mirror of https://github.com/vitalif/openscad
5798 lines
199 KiB
C++
5798 lines
199 KiB
C++
/*
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LodePNG version 20110908
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Copyright (c) 2005-2011 Lode Vandevenne
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This software is provided 'as-is', without any express or implied
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warranty. In no event will the authors be held liable for any damages
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arising from the use of this software.
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Permission is granted to anyone to use this software for any purpose,
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including commercial applications, and to alter it and redistribute it
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freely, subject to the following restrictions:
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1. The origin of this software must not be misrepresented; you must not
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claim that you wrote the original software. If you use this software
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in a product, an acknowledgment in the product documentation would be
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appreciated but is not required.
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2. Altered source versions must be plainly marked as such, and must not be
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misrepresented as being the original software.
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3. This notice may not be removed or altered from any source
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distribution.
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*/
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/*
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The manual and changelog are in the header file "lodepng.h"
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Rename this file to lodepng.cpp to use it for C++, or to lodepng.c to use it for C.
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*/
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#include "lodepng.h"
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#include <stdio.h>
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#include <stdlib.h>
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#ifdef __cplusplus
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#include <fstream>
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#endif /*__cplusplus*/
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#define VERSION_STRING "20110908"
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/*
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This source file is built up in the following large parts. The code sections
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with the "LODEPNG_COMPILE_" #defines divide this up further in an intermixed way.
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-Tools for C and common code for PNG and Zlib
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-C Code for Zlib (huffman, deflate, ...)
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-C Code for PNG (file format chunks, adam7, PNG filters, color conversions, ...)
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-The C++ wrapper around all of the above
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*/
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/* ////////////////////////////////////////////////////////////////////////// */
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/* ////////////////////////////////////////////////////////////////////////// */
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/* // Tools for C, and common code for PNG and Zlib. // */
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/* ////////////////////////////////////////////////////////////////////////// */
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/* ////////////////////////////////////////////////////////////////////////// */
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/*
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Often in case of an error a value is assigned to a variable and then it breaks
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out of a loop (to go to the cleanup phase of a function). This macro does that.
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It makes the error handling code shorter and more readable.
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Example: if(!uivector_resizev(&frequencies_ll, 286, 0)) ERROR_BREAK(9924);
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*/
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#define CERROR_BREAK(errorvar, code)\
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{\
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errorvar = code;\
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break;\
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}
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/*version of CERROR_BREAK that assumes the common case where the error variable is named "error"*/
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#define ERROR_BREAK(code) CERROR_BREAK(error, code)
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/*
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About vector, uivector, ucvector and string:
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-All of them wrap dynamic arrays or text strings in a similar way.
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-LodePNG was originally written in C++. The vectors replace the std::vectors that were used in the C++ version.
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-The string tools are made to avoid problems with compilers that declare things like strncat as deprecated.
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-They're not used in the interface, only internally in this file as static functions.
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-As with many other structs in this file, the init and cleanup functions serve as ctor and dtor.
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*/
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#ifdef LODEPNG_COMPILE_ZLIB
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#ifdef LODEPNG_COMPILE_ENCODER
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typedef struct vector /*dynamic vector of void* pointers. This one is used only by the deflate compressor*/
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{
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void* data;
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size_t size; /*in groups of bytes depending on type*/
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size_t allocsize; /*in bytes*/
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unsigned typesize; /*sizeof the type you store in data*/
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} vector;
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static unsigned vector_resize(vector* p, size_t size) /*returns 1 if success, 0 if failure ==> nothing done*/
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{
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if(size * p->typesize > p->allocsize)
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{
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size_t newsize = size * p->typesize * 2;
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void* data = realloc(p->data, newsize);
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if(data)
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{
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p->allocsize = newsize;
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p->data = data;
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p->size = size;
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}
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else return 0;
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}
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else p->size = size;
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return 1;
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}
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/*resize and use destructor on elements if it gets smaller*/
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static unsigned vector_resized(vector* p, size_t size, void dtor(void*))
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{
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size_t i;
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if(size < p->size)
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{
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for(i = size; i < p->size; i++)
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{
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dtor(&((char*)(p->data))[i * p->typesize]);
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}
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}
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return vector_resize(p, size);
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}
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static void vector_cleanup(void* p)
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{
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((vector*)p)->size = ((vector*)p)->allocsize = 0;
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free(((vector*)p)->data);
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((vector*)p)->data = NULL;
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}
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static void vector_cleanupd(vector* p, void dtor(void*)) /*clear and use destructor on elements*/
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{
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vector_resized(p, 0, dtor);
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vector_cleanup(p);
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}
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static void vector_init(vector* p, unsigned typesize)
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{
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p->data = NULL;
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p->size = p->allocsize = 0;
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p->typesize = typesize;
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}
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static void vector_swap(vector* p, vector* q) /*they're supposed to have the same typesize*/
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{
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size_t tmp;
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void* tmpp;
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tmp = p->size; p->size = q->size; q->size = tmp;
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tmp = p->allocsize; p->allocsize = q->allocsize; q->allocsize = tmp;
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tmpp = p->data; p->data = q->data; q->data = tmpp;
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}
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static void* vector_get(vector* p, size_t index)
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{
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return &((char*)p->data)[index * p->typesize];
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}
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#endif /*LODEPNG_COMPILE_ENCODER*/
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#endif /*LODEPNG_COMPILE_ZLIB*/
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/* /////////////////////////////////////////////////////////////////////////// */
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#ifdef LODEPNG_COMPILE_ZLIB
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/*dynamic vector of unsigned ints*/
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typedef struct uivector
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{
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unsigned* data;
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size_t size; /*size in number of unsigned longs*/
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size_t allocsize; /*allocated size in bytes*/
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} uivector;
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static void uivector_cleanup(void* p)
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{
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((uivector*)p)->size = ((uivector*)p)->allocsize = 0;
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free(((uivector*)p)->data);
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((uivector*)p)->data = NULL;
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}
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/*returns 1 if success, 0 if failure ==> nothing done*/
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static unsigned uivector_resize(uivector* p, size_t size)
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{
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if(size * sizeof(unsigned) > p->allocsize)
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{
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size_t newsize = size * sizeof(unsigned) * 2;
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void* data = realloc(p->data, newsize);
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if(data)
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{
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p->allocsize = newsize;
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p->data = (unsigned*)data;
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p->size = size;
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}
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else return 0;
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}
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else p->size = size;
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return 1;
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}
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/*resize and give all new elements the value*/
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static unsigned uivector_resizev(uivector* p, size_t size, unsigned value)
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{
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size_t oldsize = p->size, i;
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if(!uivector_resize(p, size)) return 0;
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for(i = oldsize; i < size; i++) p->data[i] = value;
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return 1;
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}
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static void uivector_init(uivector* p)
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{
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p->data = NULL;
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p->size = p->allocsize = 0;
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}
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#ifdef LODEPNG_COMPILE_ENCODER
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/*returns 1 if success, 0 if failure ==> nothing done*/
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static unsigned uivector_push_back(uivector* p, unsigned c)
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{
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if(!uivector_resize(p, p->size + 1)) return 0;
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p->data[p->size - 1] = c;
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return 1;
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}
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/*copy q to p, returns 1 if success, 0 if failure ==> nothing done*/
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static unsigned uivector_copy(uivector* p, const uivector* q)
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{
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size_t i;
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if(!uivector_resize(p, q->size)) return 0;
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for(i = 0; i < q->size; i++) p->data[i] = q->data[i];
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return 1;
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}
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static void uivector_swap(uivector* p, uivector* q)
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{
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size_t tmp;
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unsigned* tmpp;
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tmp = p->size; p->size = q->size; q->size = tmp;
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tmp = p->allocsize; p->allocsize = q->allocsize; q->allocsize = tmp;
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tmpp = p->data; p->data = q->data; q->data = tmpp;
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}
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#endif /*LODEPNG_COMPILE_ENCODER*/
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#endif /*LODEPNG_COMPILE_ZLIB*/
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/* /////////////////////////////////////////////////////////////////////////// */
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/*dynamic vector of unsigned chars*/
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typedef struct ucvector
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{
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unsigned char* data;
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size_t size; /*used size*/
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size_t allocsize; /*allocated size*/
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} ucvector;
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static void ucvector_cleanup(void* p)
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{
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((ucvector*)p)->size = ((ucvector*)p)->allocsize = 0;
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free(((ucvector*)p)->data);
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((ucvector*)p)->data = NULL;
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}
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/*returns 1 if success, 0 if failure ==> nothing done*/
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static unsigned ucvector_resize(ucvector* p, size_t size)
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{
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if(size * sizeof(unsigned char) > p->allocsize)
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{
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size_t newsize = size * sizeof(unsigned char) * 2;
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void* data = realloc(p->data, newsize);
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if(data)
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{
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p->allocsize = newsize;
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p->data = (unsigned char*)data;
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p->size = size;
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}
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else return 0; /*error: not enough memory*/
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}
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else p->size = size;
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return 1;
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}
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#ifdef LODEPNG_COMPILE_DECODER
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#ifdef LODEPNG_COMPILE_PNG
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/*resize and give all new elements the value*/
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static unsigned ucvector_resizev(ucvector* p, size_t size, unsigned char value)
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{
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size_t oldsize = p->size, i;
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if(!ucvector_resize(p, size)) return 0;
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for(i = oldsize; i < size; i++) p->data[i] = value;
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return 1;
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}
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#endif /*LODEPNG_COMPILE_PNG*/
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#endif /*LODEPNG_COMPILE_DECODER*/
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static void ucvector_init(ucvector* p)
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{
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p->data = NULL;
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p->size = p->allocsize = 0;
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}
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#ifdef LODEPNG_COMPILE_ZLIB
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/*you can both convert from vector to buffer&size and vica versa. If you use
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init_buffer to take over a buffer and size, it is not needed to use cleanup*/
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static void ucvector_init_buffer(ucvector* p, unsigned char* buffer, size_t size)
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{
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p->data = buffer;
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p->allocsize = p->size = size;
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}
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#endif /*LODEPNG_COMPILE_ZLIB*/
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#ifdef LODEPNG_COMPILE_ENCODER
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/*returns 1 if success, 0 if failure ==> nothing done*/
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static unsigned ucvector_push_back(ucvector* p, unsigned char c)
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{
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if(!ucvector_resize(p, p->size + 1)) return 0;
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p->data[p->size - 1] = c;
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return 1;
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}
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#endif /*LODEPNG_COMPILE_ENCODER*/
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/* ////////////////////////////////////////////////////////////////////////// */
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#ifdef LODEPNG_COMPILE_PNG
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#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
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/*returns 1 if success, 0 if failure ==> nothing done*/
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static unsigned string_resize(char** out, size_t size)
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{
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char* data = (char*)realloc(*out, size + 1);
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if(data)
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{
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data[size] = 0; /*null termination char*/
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*out = data;
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}
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return data != 0;
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}
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/*init a {char*, size_t} pair for use as string*/
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static void string_init(char** out)
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{
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*out = NULL;
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string_resize(out, 0);
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}
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/*free the above pair again*/
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static void string_cleanup(char** out)
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{
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free(*out);
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*out = NULL;
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}
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static void string_set(char** out, const char* in)
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{
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size_t insize = strlen(in), i = 0;
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if(string_resize(out, insize))
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{
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for(i = 0; i < insize; i++)
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{
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(*out)[i] = in[i];
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}
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}
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}
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#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
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#endif /*LODEPNG_COMPILE_PNG*/
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/* ////////////////////////////////////////////////////////////////////////// */
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unsigned LodePNG_read32bitInt(const unsigned char* buffer)
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{
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return (buffer[0] << 24) | (buffer[1] << 16) | (buffer[2] << 8) | buffer[3];
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}
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/*buffer must have at least 4 allocated bytes available*/
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static void LodePNG_set32bitInt(unsigned char* buffer, unsigned value)
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{
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buffer[0] = (unsigned char)((value >> 24) & 0xff);
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buffer[1] = (unsigned char)((value >> 16) & 0xff);
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buffer[2] = (unsigned char)((value >> 8) & 0xff);
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buffer[3] = (unsigned char)((value ) & 0xff);
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}
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#ifdef LODEPNG_COMPILE_ENCODER
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static void LodePNG_add32bitInt(ucvector* buffer, unsigned value)
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{
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ucvector_resize(buffer, buffer->size + 4); /*todo: give error if resize failed*/
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LodePNG_set32bitInt(&buffer->data[buffer->size - 4], value);
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}
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#endif /*LODEPNG_COMPILE_ENCODER*/
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/* ////////////////////////////////////////////////////////////////////////// */
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/* / File IO / */
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/* ////////////////////////////////////////////////////////////////////////// */
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#ifdef LODEPNG_COMPILE_DISK
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unsigned LodePNG_loadFile(unsigned char** out, size_t* outsize, const char* filename)
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{
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FILE* file;
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long size;
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/*provide some proper output values if error will happen*/
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*out = 0;
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*outsize = 0;
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file = fopen(filename, "rb");
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if(!file) return 78;
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/*get filesize:*/
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fseek(file , 0 , SEEK_END);
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size = ftell(file);
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rewind(file);
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/*read contents of the file into the vector*/
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*outsize = 0;
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*out = (unsigned char*)malloc((size_t)size);
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if(size && (*out)) (*outsize) = fread(*out, 1, (size_t)size, file);
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fclose(file);
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if(!(*out) && size) return 9900; /*the above malloc failed*/
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return 0;
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}
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/*write given buffer to the file, overwriting the file, it doesn't append to it.*/
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unsigned LodePNG_saveFile(const unsigned char* buffer, size_t buffersize, const char* filename)
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{
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FILE* file;
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file = fopen(filename, "wb" );
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if(!file) return 79;
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fwrite((char*)buffer , 1 , buffersize, file);
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fclose(file);
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return 0;
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}
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#endif /*LODEPNG_COMPILE_DISK*/
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/* ////////////////////////////////////////////////////////////////////////// */
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/* ////////////////////////////////////////////////////////////////////////// */
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/* // End of common code and tools. Begin of Zlib related code. // */
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/* ////////////////////////////////////////////////////////////////////////// */
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/* ////////////////////////////////////////////////////////////////////////// */
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#ifdef LODEPNG_COMPILE_ZLIB
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/* ////////////////////////////////////////////////////////////////////////// */
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/* / Reading and writing single bits and bytes from/to stream for Deflate / */
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/* ////////////////////////////////////////////////////////////////////////// */
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#ifdef LODEPNG_COMPILE_ENCODER
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/*TODO: this ignores potential out of memory errors*/
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static void addBitToStream(size_t* bitpointer, ucvector* bitstream, unsigned char bit)
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{
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/*add a new byte at the end*/
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if((*bitpointer) % 8 == 0) ucvector_push_back(bitstream, (unsigned char)0);
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/*earlier bit of huffman code is in a lesser significant bit of an earlier byte*/
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(bitstream->data[bitstream->size - 1]) |= (bit << ((*bitpointer) & 0x7));
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(*bitpointer)++;
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}
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static void addBitsToStream(size_t* bitpointer, ucvector* bitstream, unsigned value, size_t nbits)
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{
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size_t i;
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for(i = 0; i < nbits; i++) addBitToStream(bitpointer, bitstream, (unsigned char)((value >> i) & 1));
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}
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static void addBitsToStreamReversed(size_t* bitpointer, ucvector* bitstream, unsigned value, size_t nbits)
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{
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size_t i;
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for(i = 0; i < nbits; i++) addBitToStream(bitpointer, bitstream, (unsigned char)((value >> (nbits - 1 - i)) & 1));
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}
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#endif /*LODEPNG_COMPILE_ENCODER*/
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#ifdef LODEPNG_COMPILE_DECODER
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#define READBIT(bitpointer, bitstream) ((bitstream[bitpointer >> 3] >> (bitpointer & 0x7)) & (unsigned char)1)
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static unsigned char readBitFromStream(size_t* bitpointer, const unsigned char* bitstream)
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{
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unsigned char result = (unsigned char)(READBIT(*bitpointer, bitstream));
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(*bitpointer)++;
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return result;
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}
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static unsigned readBitsFromStream(size_t* bitpointer, const unsigned char* bitstream, size_t nbits)
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{
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unsigned result = 0, i;
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for(i = 0; i < nbits; i++)
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{
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result += ((unsigned)READBIT(*bitpointer, bitstream)) << i;
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(*bitpointer)++;
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}
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return result;
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}
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#endif /*LODEPNG_COMPILE_DECODER*/
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/* ////////////////////////////////////////////////////////////////////////// */
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/* / Deflate - Huffman / */
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/* ////////////////////////////////////////////////////////////////////////// */
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#define FIRST_LENGTH_CODE_INDEX 257
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#define LAST_LENGTH_CODE_INDEX 285
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/*256 literals, the end code, some length codes, and 2 unused codes*/
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#define NUM_DEFLATE_CODE_SYMBOLS 288
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/*the distance codes have their own symbols, 30 used, 2 unused*/
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#define NUM_DISTANCE_SYMBOLS 32
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/*the code length codes. 0-15: code lengths, 16: copy previous 3-6 times, 17: 3-10 zeros, 18: 11-138 zeros*/
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#define NUM_CODE_LENGTH_CODES 19
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|
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/*the base lengths represented by codes 257-285*/
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static const unsigned LENGTHBASE[29]
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= {3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31, 35, 43, 51, 59,
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67, 83, 99, 115, 131, 163, 195, 227, 258};
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|
|
/*the extra bits used by codes 257-285 (added to base length)*/
|
|
static const unsigned LENGTHEXTRA[29]
|
|
= {0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3,
|
|
4, 4, 4, 4, 5, 5, 5, 5, 0};
|
|
|
|
/*the base backwards distances (the bits of distance codes appear after length codes and use their own huffman tree)*/
|
|
static const unsigned DISTANCEBASE[30]
|
|
= {1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193, 257, 385, 513,
|
|
769, 1025, 1537, 2049, 3073, 4097, 6145, 8193, 12289, 16385, 24577};
|
|
|
|
/*the extra bits of backwards distances (added to base)*/
|
|
static const unsigned DISTANCEEXTRA[30]
|
|
= {0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8,
|
|
8, 9, 9, 10, 10, 11, 11, 12, 12, 13, 13};
|
|
|
|
/*the order in which "code length alphabet code lengths" are stored, out of this
|
|
the huffman tree of the dynamic huffman tree lengths is generated*/
|
|
static const unsigned CLCL_ORDER[NUM_CODE_LENGTH_CODES]
|
|
= {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
|
|
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
|
|
/*
|
|
Huffman tree struct, containing multiple representations of the tree
|
|
*/
|
|
typedef struct HuffmanTree
|
|
{
|
|
uivector tree2d;
|
|
uivector tree1d;
|
|
uivector lengths; /*the lengths of the codes of the 1d-tree*/
|
|
unsigned maxbitlen; /*maximum number of bits a single code can get*/
|
|
unsigned numcodes; /*number of symbols in the alphabet = number of codes*/
|
|
} HuffmanTree;
|
|
|
|
/*function used for debug purposes to draw the tree in ascii art with C++*/
|
|
/*#include <iostream>
|
|
static void HuffmanTree_draw(HuffmanTree* tree)
|
|
{
|
|
std::cout << "tree. length: " << tree->numcodes << " maxbitlen: " << tree->maxbitlen << std::endl;
|
|
for(size_t i = 0; i < tree->tree1d.size; i++)
|
|
{
|
|
if(tree->lengths.data[i])
|
|
std::cout << i << " " << tree->tree1d.data[i] << " " << tree->lengths.data[i] << std::endl;
|
|
}
|
|
std::cout << std::endl;
|
|
}*/
|
|
|
|
static void HuffmanTree_init(HuffmanTree* tree)
|
|
{
|
|
uivector_init(&tree->tree2d);
|
|
uivector_init(&tree->tree1d);
|
|
uivector_init(&tree->lengths);
|
|
}
|
|
|
|
static void HuffmanTree_cleanup(HuffmanTree* tree)
|
|
{
|
|
uivector_cleanup(&tree->tree2d);
|
|
uivector_cleanup(&tree->tree1d);
|
|
uivector_cleanup(&tree->lengths);
|
|
}
|
|
|
|
/*the tree representation used by the decoder. return value is error*/
|
|
static unsigned HuffmanTree_make2DTree(HuffmanTree* tree)
|
|
{
|
|
unsigned nodefilled = 0; /*up to which node it is filled*/
|
|
unsigned treepos = 0; /*position in the tree (1 of the numcodes columns)*/
|
|
unsigned n, i;
|
|
|
|
if(!uivector_resize(&tree->tree2d, tree->numcodes * 2)) return 9901; /*alloc fail*/
|
|
|
|
/*
|
|
convert tree1d[] to tree2d[][]. In the 2D array, a value of 32767 means
|
|
uninited, a value >= numcodes is an address to another bit, a value < numcodes
|
|
is a code. The 2 rows are the 2 possible bit values (0 or 1), there are as
|
|
many columns as codes - 1.
|
|
A good huffmann tree has N * 2 - 1 nodes, of which N - 1 are internal nodes.
|
|
Here, the internal nodes are stored (what their 0 and 1 option point to).
|
|
There is only memory for such good tree currently, if there are more nodes
|
|
(due to too long length codes), error 55 will happen
|
|
*/
|
|
for(n = 0; n < tree->numcodes * 2; n++)
|
|
{
|
|
tree->tree2d.data[n] = 32767; /*32767 here means the tree2d isn't filled there yet*/
|
|
}
|
|
|
|
for(n = 0; n < tree->numcodes; n++) /*the codes*/
|
|
{
|
|
for(i = 0; i < tree->lengths.data[n]; i++) /*the bits for this code*/
|
|
{
|
|
unsigned char bit = (unsigned char)((tree->tree1d.data[n] >> (tree->lengths.data[n] - i - 1)) & 1);
|
|
if(treepos > tree->numcodes - 2) return 55; /*error 55: oversubscribed; see description in header*/
|
|
if(tree->tree2d.data[2 * treepos + bit] == 32767) /*not yet filled in*/
|
|
{
|
|
if(i + 1 == tree->lengths.data[n]) /*last bit*/
|
|
{
|
|
tree->tree2d.data[2 * treepos + bit] = n; /*put the current code in it*/
|
|
treepos = 0;
|
|
}
|
|
else
|
|
{
|
|
/*put address of the next step in here, first that address has to be found of course
|
|
(it's just nodefilled + 1)...*/
|
|
nodefilled++;
|
|
/*addresses encoded with numcodes added to it*/
|
|
tree->tree2d.data[2 * treepos + bit] = nodefilled + tree->numcodes;
|
|
treepos = nodefilled;
|
|
}
|
|
}
|
|
else treepos = tree->tree2d.data[2 * treepos + bit] - tree->numcodes;
|
|
}
|
|
}
|
|
|
|
for(n = 0; n < tree->numcodes * 2; n++)
|
|
{
|
|
if(tree->tree2d.data[n] == 32767) tree->tree2d.data[n] = 0; /*remove possible remaining 32767's*/
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
Second step for the ...makeFromLengths and ...makeFromFrequencies functions.
|
|
numcodes, lengths and maxbitlen must already be filled in correctly. return
|
|
value is error.
|
|
*/
|
|
static unsigned HuffmanTree_makeFromLengths2(HuffmanTree* tree)
|
|
{
|
|
uivector blcount;
|
|
uivector nextcode;
|
|
unsigned bits, n, error = 0;
|
|
|
|
uivector_init(&blcount);
|
|
uivector_init(&nextcode);
|
|
if(!uivector_resize(&tree->tree1d, tree->numcodes)
|
|
|| !uivector_resizev(&blcount, tree->maxbitlen + 1, 0)
|
|
|| !uivector_resizev(&nextcode, tree->maxbitlen + 1, 0))
|
|
error = 9902; /*alloc fail*/
|
|
|
|
if(!error)
|
|
{
|
|
/*step 1: count number of instances of each code length*/
|
|
for(bits = 0; bits < tree->numcodes; bits++) blcount.data[tree->lengths.data[bits]]++;
|
|
/*step 2: generate the nextcode values*/
|
|
for(bits = 1; bits <= tree->maxbitlen; bits++)
|
|
{
|
|
nextcode.data[bits] = (nextcode.data[bits - 1] + blcount.data[bits - 1]) << 1;
|
|
}
|
|
/*step 3: generate all the codes*/
|
|
for(n = 0; n < tree->numcodes; n++)
|
|
{
|
|
if(tree->lengths.data[n] != 0) tree->tree1d.data[n] = nextcode.data[tree->lengths.data[n]]++;
|
|
}
|
|
}
|
|
|
|
uivector_cleanup(&blcount);
|
|
uivector_cleanup(&nextcode);
|
|
|
|
if(!error) return HuffmanTree_make2DTree(tree);
|
|
else return error;
|
|
}
|
|
|
|
/*
|
|
given the code lengths (as stored in the PNG file), generate the tree as defined
|
|
by Deflate. maxbitlen is the maximum bits that a code in the tree can have.
|
|
return value is error.
|
|
*/
|
|
static unsigned HuffmanTree_makeFromLengths(HuffmanTree* tree, const unsigned* bitlen,
|
|
size_t numcodes, unsigned maxbitlen)
|
|
{
|
|
unsigned i;
|
|
if(!uivector_resize(&tree->lengths, numcodes)) return 9903; /*alloc fail*/
|
|
for(i = 0; i < numcodes; i++) tree->lengths.data[i] = bitlen[i];
|
|
tree->numcodes = (unsigned)numcodes; /*number of symbols*/
|
|
tree->maxbitlen = maxbitlen;
|
|
return HuffmanTree_makeFromLengths2(tree);
|
|
}
|
|
|
|
#ifdef LODEPNG_COMPILE_ENCODER
|
|
|
|
/*
|
|
A coin, this is the terminology used for the package-merge algorithm and the
|
|
coin collector's problem. This is used to generate the huffman tree.
|
|
A coin can be multiple coins (when they're merged)
|
|
*/
|
|
typedef struct Coin
|
|
{
|
|
uivector symbols;
|
|
float weight; /*the sum of all weights in this coin*/
|
|
} Coin;
|
|
|
|
static void Coin_init(Coin* c)
|
|
{
|
|
uivector_init(&c->symbols);
|
|
}
|
|
|
|
/*argument c is void* so that this dtor can be given as function pointer to the vector resize function*/
|
|
static void Coin_cleanup(void* c)
|
|
{
|
|
uivector_cleanup(&((Coin*)c)->symbols);
|
|
}
|
|
|
|
static void Coin_copy(Coin* c1, const Coin* c2)
|
|
{
|
|
c1->weight = c2->weight;
|
|
uivector_copy(&c1->symbols, &c2->symbols);
|
|
}
|
|
|
|
static void addCoins(Coin* c1, const Coin* c2)
|
|
{
|
|
size_t i;
|
|
for(i = 0; i < c2->symbols.size; i++) uivector_push_back(&c1->symbols, c2->symbols.data[i]);
|
|
c1->weight += c2->weight;
|
|
}
|
|
|
|
/*
|
|
Coin_sort: This uses a simple combsort to sort the data. This function is not critical for
|
|
overall encoding speed and the data amount isn't that large.
|
|
*/
|
|
static void Coin_sort(Coin* data, size_t amount)
|
|
{
|
|
size_t gap = amount;
|
|
unsigned char swapped = 0;
|
|
while((gap > 1) || swapped)
|
|
{
|
|
size_t i;
|
|
gap = (gap * 10) / 13; /*shrink factor 1.3*/
|
|
if(gap == 9 || gap == 10) gap = 11; /*combsort11*/
|
|
if(gap < 1) gap = 1;
|
|
swapped = 0;
|
|
for(i = 0; i < amount - gap; i++)
|
|
{
|
|
size_t j = i + gap;
|
|
if(data[j].weight < data[i].weight)
|
|
{
|
|
float temp = data[j].weight; data[j].weight = data[i].weight; data[i].weight = temp;
|
|
uivector_swap(&data[i].symbols, &data[j].symbols);
|
|
swapped = 1;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
static unsigned HuffmanTree_fillInCoins(vector* coins, const unsigned* frequencies, unsigned numcodes, size_t sum)
|
|
{
|
|
unsigned i;
|
|
for(i = 0; i < numcodes; i++)
|
|
{
|
|
Coin* coin;
|
|
if(frequencies[i] == 0) continue; /*it's important to exclude symbols that aren't present*/
|
|
if(!vector_resize(coins, coins->size + 1))
|
|
{
|
|
vector_cleanup(coins);
|
|
return 9904; /*alloc fail*/
|
|
}
|
|
coin = (Coin*)(vector_get(coins, coins->size - 1));
|
|
Coin_init(coin);
|
|
coin->weight = frequencies[i] / (float)sum;
|
|
uivector_push_back(&coin->symbols, i);
|
|
}
|
|
if(coins->size) Coin_sort((Coin*)coins->data, coins->size);
|
|
return 0;
|
|
}
|
|
|
|
/*Create the Huffman tree given the symbol frequencies*/
|
|
static unsigned HuffmanTree_makeFromFrequencies(HuffmanTree* tree, const unsigned* frequencies,
|
|
size_t numcodes, unsigned maxbitlen)
|
|
{
|
|
unsigned i, j;
|
|
size_t sum = 0, numpresent = 0;
|
|
unsigned error = 0;
|
|
|
|
vector prev_row; /*type Coin, the previous row of coins*/
|
|
vector coins; /*type Coin, the coins of the currently calculated row*/
|
|
|
|
tree->maxbitlen = maxbitlen;
|
|
|
|
for(i = 0; i < numcodes; i++)
|
|
{
|
|
if(frequencies[i] > 0)
|
|
{
|
|
numpresent++;
|
|
sum += frequencies[i];
|
|
}
|
|
}
|
|
|
|
if(numcodes == 0) return 80; /*error: a tree of 0 symbols is not supposed to be made*/
|
|
tree->numcodes = (unsigned)numcodes; /*number of symbols*/
|
|
uivector_resize(&tree->lengths, 0);
|
|
if(!uivector_resizev(&tree->lengths, tree->numcodes, 0)) return 9905; /*alloc fail*/
|
|
|
|
/*there are no symbols at all, in that case add one symbol of value 0 to the tree (see RFC 1951 section 3.2.7) */
|
|
if(numpresent == 0)
|
|
{
|
|
tree->lengths.data[0] = 1;
|
|
return HuffmanTree_makeFromLengths2(tree);
|
|
}
|
|
/*the package merge algorithm gives wrong results if there's only one symbol
|
|
(theoretically 0 bits would then suffice, but we need a proper symbol for zlib)*/
|
|
else if(numpresent == 1)
|
|
{
|
|
for(i = 0; i < numcodes; i++) if(frequencies[i]) tree->lengths.data[i] = 1;
|
|
return HuffmanTree_makeFromLengths2(tree);
|
|
}
|
|
|
|
vector_init(&coins, sizeof(Coin));
|
|
vector_init(&prev_row, sizeof(Coin));
|
|
|
|
/*Package-Merge algorithm represented by coin collector's problem
|
|
For every symbol, maxbitlen coins will be created*/
|
|
|
|
/*first row, lowest denominator*/
|
|
error = HuffmanTree_fillInCoins(&coins, frequencies, tree->numcodes, sum);
|
|
if(!error)
|
|
{
|
|
for(j = 1; j <= maxbitlen && !error; j++) /*each of the remaining rows*/
|
|
{
|
|
vector_swap(&coins, &prev_row); /*swap instead of copying*/
|
|
if(!vector_resized(&coins, 0, Coin_cleanup)) ERROR_BREAK(9906 /*alloc fail*/);
|
|
for(i = 0; i + 1 < prev_row.size; i += 2)
|
|
{
|
|
if(!vector_resize(&coins, coins.size + 1)) ERROR_BREAK(9907 /*alloc fail*/);
|
|
Coin_init((Coin*)vector_get(&coins, coins.size - 1));
|
|
Coin_copy((Coin*)vector_get(&coins, coins.size - 1), (Coin*)vector_get(&prev_row, i));
|
|
/*merge the coins into packages*/
|
|
addCoins((Coin*)vector_get(&coins, coins.size - 1), (Coin*)vector_get(&prev_row, i + 1));
|
|
}
|
|
if(j < maxbitlen)
|
|
{
|
|
error = HuffmanTree_fillInCoins(&coins, frequencies, tree->numcodes, sum);
|
|
}
|
|
}
|
|
}
|
|
|
|
if(!error)
|
|
{
|
|
/*keep the coins with lowest weight, so that they add up to the amount of symbols - 1*/
|
|
vector_resized(&coins, numpresent - 1, Coin_cleanup);
|
|
|
|
/*calculate the lenghts of each symbol, as the amount of times a coin of each symbol is used*/
|
|
for(i = 0; i < coins.size; i++)
|
|
{
|
|
Coin* coin = (Coin*)vector_get(&coins, i);
|
|
for(j = 0; j < coin->symbols.size; j++) tree->lengths.data[coin->symbols.data[j]]++;
|
|
}
|
|
|
|
error = HuffmanTree_makeFromLengths2(tree);
|
|
}
|
|
|
|
vector_cleanupd(&coins, Coin_cleanup);
|
|
vector_cleanupd(&prev_row, Coin_cleanup);
|
|
|
|
return error;
|
|
}
|
|
|
|
static unsigned HuffmanTree_getCode(const HuffmanTree* tree, unsigned index)
|
|
{
|
|
return tree->tree1d.data[index];
|
|
}
|
|
|
|
static unsigned HuffmanTree_getLength(const HuffmanTree* tree, unsigned index)
|
|
{
|
|
return tree->lengths.data[index];
|
|
}
|
|
#endif /*LODEPNG_COMPILE_ENCODER*/
|
|
|
|
/*get the literal and length code tree of a deflated block with fixed tree, as per the deflate specification*/
|
|
static unsigned generateFixedLitLenTree(HuffmanTree* tree)
|
|
{
|
|
unsigned i, error = 0;
|
|
uivector bitlen;
|
|
uivector_init(&bitlen);
|
|
if(!uivector_resize(&bitlen, NUM_DEFLATE_CODE_SYMBOLS)) error = 9909; /*alloc fail*/
|
|
|
|
if(!error)
|
|
{
|
|
/*288 possible codes: 0-255=literals, 256=endcode, 257-285=lengthcodes, 286-287=unused*/
|
|
for(i = 0; i <= 143; i++) bitlen.data[i] = 8;
|
|
for(i = 144; i <= 255; i++) bitlen.data[i] = 9;
|
|
for(i = 256; i <= 279; i++) bitlen.data[i] = 7;
|
|
for(i = 280; i <= 287; i++) bitlen.data[i] = 8;
|
|
|
|
error = HuffmanTree_makeFromLengths(tree, bitlen.data, NUM_DEFLATE_CODE_SYMBOLS, 15);
|
|
}
|
|
|
|
uivector_cleanup(&bitlen);
|
|
return error;
|
|
}
|
|
|
|
/*get the distance code tree of a deflated block with fixed tree, as specified in the deflate specification*/
|
|
static unsigned generateFixedDistanceTree(HuffmanTree* tree)
|
|
{
|
|
unsigned i, error = 0;
|
|
uivector bitlen;
|
|
uivector_init(&bitlen);
|
|
if(!uivector_resize(&bitlen, NUM_DISTANCE_SYMBOLS)) error = 9910; /*alloc fail*/
|
|
|
|
/*there are 32 distance codes, but 30-31 are unused*/
|
|
if(!error)
|
|
{
|
|
for(i = 0; i < NUM_DISTANCE_SYMBOLS; i++) bitlen.data[i] = 5;
|
|
error = HuffmanTree_makeFromLengths(tree, bitlen.data, NUM_DISTANCE_SYMBOLS, 15);
|
|
}
|
|
uivector_cleanup(&bitlen);
|
|
return error;
|
|
}
|
|
|
|
#ifdef LODEPNG_COMPILE_DECODER
|
|
|
|
/*
|
|
returns the code, or (unsigned)(-1) if error happened
|
|
inbitlength is the length of the complete buffer, in bits (so its byte length times 8)
|
|
*/
|
|
static unsigned huffmanDecodeSymbol(const unsigned char* in, size_t* bp,
|
|
const HuffmanTree* codetree, size_t inbitlength)
|
|
{
|
|
unsigned treepos = 0, ct;
|
|
for(;;)
|
|
{
|
|
if(*bp > inbitlength) return (unsigned)(-1); /*error: end of input memory reached without endcode*/
|
|
|
|
/*
|
|
decode the symbol from the tree. The "readBitFromStream" code is inlined in
|
|
the expression below because this is the biggest bottleneck while decoding
|
|
*/
|
|
ct = codetree->tree2d.data[(treepos << 1) + READBIT(*bp, in)];
|
|
(*bp)++;
|
|
if(ct < codetree->numcodes) return ct; /*the symbol is decoded, return it*/
|
|
else treepos = ct - codetree->numcodes; /*symbol not yet decoded, instead move tree position*/
|
|
|
|
if(treepos >= codetree->numcodes) return (unsigned)(-1); /*error: it appeared outside the codetree*/
|
|
}
|
|
}
|
|
#endif /*LODEPNG_COMPILE_DECODER*/
|
|
|
|
#ifdef LODEPNG_COMPILE_DECODER
|
|
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
/* / Inflator (Decompressor) / */
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
|
|
/*get the tree of a deflated block with fixed tree, as specified in the deflate specification*/
|
|
static void getTreeInflateFixed(HuffmanTree* tree_ll, HuffmanTree* tree_d)
|
|
{
|
|
/*error checking not done, this is fixed stuff, it works, it doesn't depend on the image*/
|
|
/*TODO: out of memory errors could still happen...*/
|
|
generateFixedLitLenTree(tree_ll);
|
|
generateFixedDistanceTree(tree_d);
|
|
}
|
|
|
|
/*get the tree of a deflated block with dynamic tree, the tree itself is also Huffman compressed with a known tree*/
|
|
static unsigned getTreeInflateDynamic(HuffmanTree* tree_ll, HuffmanTree* tree_d,
|
|
const unsigned char* in, size_t* bp, size_t inlength)
|
|
{
|
|
/*make sure that length values that aren't filled in will be 0, or a wrong tree will be generated*/
|
|
unsigned error = 0;
|
|
unsigned n, HLIT, HDIST, HCLEN, i;
|
|
size_t inbitlength = inlength * 8;
|
|
|
|
/*see comments in deflateDynamic for explanation of the context and these variables, it is analogous*/
|
|
uivector bitlen_ll; /*lit,len code lengths*/
|
|
uivector bitlen_d; /*dist code lengths*/
|
|
/*code length code lengths ("clcl"), the bit lengths of the huffman tree used to compress bitlen_ll and bitlen_d*/
|
|
uivector bitlen_cl;
|
|
HuffmanTree tree_cl; /*the code tree for code length codes (the huffman tree for compressed huffman trees)*/
|
|
|
|
if((*bp) >> 3 >= inlength - 2) return 49; /*the bit pointer is or will go past the memory*/
|
|
|
|
/*number of literal/length codes + 257. Unlike the spec, the value 257 is added to it here already*/
|
|
HLIT = readBitsFromStream(bp, in, 5) + 257;
|
|
/*number of distance codes. Unlike the spec, the value 1 is added to it here already*/
|
|
HDIST = readBitsFromStream(bp, in, 5) + 1;
|
|
/*number of code length codes. Unlike the spec, the value 4 is added to it here already*/
|
|
HCLEN = readBitsFromStream(bp, in, 4) + 4;
|
|
|
|
HuffmanTree_init(&tree_cl);
|
|
uivector_init(&bitlen_ll);
|
|
uivector_init(&bitlen_d);
|
|
uivector_init(&bitlen_cl);
|
|
|
|
while(!error)
|
|
{
|
|
/*read the code length codes out of 3 * (amount of code length codes) bits*/
|
|
|
|
if(!uivector_resize(&bitlen_cl, NUM_CODE_LENGTH_CODES)) ERROR_BREAK(9911);
|
|
|
|
for(i = 0; i < NUM_CODE_LENGTH_CODES; i++)
|
|
{
|
|
if(i < HCLEN) bitlen_cl.data[CLCL_ORDER[i]] = readBitsFromStream(bp, in, 3);
|
|
else bitlen_cl.data[CLCL_ORDER[i]] = 0; /*if not, it must stay 0*/
|
|
}
|
|
|
|
error = HuffmanTree_makeFromLengths(&tree_cl, bitlen_cl.data, bitlen_cl.size, 7);
|
|
if(error) break;
|
|
|
|
/*now we can use this tree to read the lengths for the tree that this function will return*/
|
|
uivector_resizev(&bitlen_ll, NUM_DEFLATE_CODE_SYMBOLS, 0);
|
|
uivector_resizev(&bitlen_d, NUM_DISTANCE_SYMBOLS, 0);
|
|
i = 0;
|
|
if(!bitlen_ll.data || !bitlen_d.data) ERROR_BREAK(9912); /*alloc fail*/
|
|
|
|
/*i is the current symbol we're reading in the part that contains the code lengths of lit/len and dist codes*/
|
|
while(i < HLIT + HDIST)
|
|
{
|
|
unsigned code = huffmanDecodeSymbol(in, bp, &tree_cl, inbitlength);
|
|
if(code <= 15) /*a length code*/
|
|
{
|
|
if(i < HLIT) bitlen_ll.data[i] = code;
|
|
else bitlen_d.data[i - HLIT] = code;
|
|
i++;
|
|
}
|
|
else if(code == 16) /*repeat previous*/
|
|
{
|
|
unsigned replength = 3; /*read in the 2 bits that indicate repeat length (3-6)*/
|
|
unsigned value; /*set value to the previous code*/
|
|
|
|
if((*bp) >> 3 >= inlength) ERROR_BREAK(50); /*error, bit pointer jumps past memory*/
|
|
|
|
replength += readBitsFromStream(bp, in, 2);
|
|
|
|
if((i - 1) < HLIT) value = bitlen_ll.data[i - 1];
|
|
else value = bitlen_d.data[i - HLIT - 1];
|
|
/*repeat this value in the next lengths*/
|
|
for(n = 0; n < replength; n++)
|
|
{
|
|
if(i >= HLIT + HDIST) ERROR_BREAK(13); /*error: i is larger than the amount of codes*/
|
|
if(i < HLIT) bitlen_ll.data[i] = value;
|
|
else bitlen_d.data[i - HLIT] = value;
|
|
i++;
|
|
}
|
|
}
|
|
else if(code == 17) /*repeat "0" 3-10 times*/
|
|
{
|
|
unsigned replength = 3; /*read in the bits that indicate repeat length*/
|
|
if((*bp) >> 3 >= inlength) ERROR_BREAK(50); /*error, bit pointer jumps past memory*/
|
|
|
|
replength += readBitsFromStream(bp, in, 3);
|
|
|
|
/*repeat this value in the next lengths*/
|
|
for(n = 0; n < replength; n++)
|
|
{
|
|
if(i >= HLIT + HDIST) ERROR_BREAK(14); /*error: i is larger than the amount of codes*/
|
|
|
|
if(i < HLIT) bitlen_ll.data[i] = 0;
|
|
else bitlen_d.data[i - HLIT] = 0;
|
|
i++;
|
|
}
|
|
}
|
|
else if(code == 18) /*repeat "0" 11-138 times*/
|
|
{
|
|
unsigned replength = 11; /*read in the bits that indicate repeat length*/
|
|
if((*bp) >> 3 >= inlength) ERROR_BREAK(50); /*error, bit pointer jumps past memory*/
|
|
|
|
replength += readBitsFromStream(bp, in, 7);
|
|
|
|
/*repeat this value in the next lengths*/
|
|
for(n = 0; n < replength; n++)
|
|
{
|
|
if(i >= HLIT + HDIST) ERROR_BREAK(15); /*error: i is larger than the amount of codes*/
|
|
|
|
if(i < HLIT) bitlen_ll.data[i] = 0;
|
|
else bitlen_d.data[i - HLIT] = 0;
|
|
i++;
|
|
}
|
|
}
|
|
else /*if(code == (unsigned)(-1))*/ /*huffmanDecodeSymbol returns (unsigned)(-1) in case of error*/
|
|
{
|
|
if(code == (unsigned)(-1))
|
|
{
|
|
/*return error code 10 or 11 depending on the situation that happened in huffmanDecodeSymbol
|
|
(10=no endcode, 11=wrong jump outside of tree)*/
|
|
error = (*bp) > inlength * 8 ? 10 : 11;
|
|
}
|
|
else error = 16; /*unexisting code, this can never happen*/
|
|
break;
|
|
}
|
|
}
|
|
if(error) break;
|
|
|
|
if(bitlen_ll.data[256] == 0) ERROR_BREAK(64); /*the length of the end code 256 must be larger than 0*/
|
|
|
|
/*now we've finally got HLIT and HDIST, so generate the code trees, and the function is done*/
|
|
error = HuffmanTree_makeFromLengths(tree_ll, &bitlen_ll.data[0], bitlen_ll.size, 15);
|
|
if(error) break;
|
|
error = HuffmanTree_makeFromLengths(tree_d, &bitlen_d.data[0], bitlen_d.size, 15);
|
|
|
|
break; /*end of error-while*/
|
|
}
|
|
|
|
uivector_cleanup(&bitlen_cl);
|
|
uivector_cleanup(&bitlen_ll);
|
|
uivector_cleanup(&bitlen_d);
|
|
HuffmanTree_cleanup(&tree_cl);
|
|
|
|
return error;
|
|
}
|
|
|
|
/*inflate a block with dynamic of fixed Huffman tree*/
|
|
static unsigned inflateHuffmanBlock(ucvector* out, const unsigned char* in, size_t* bp,
|
|
size_t* pos, size_t inlength, unsigned btype)
|
|
{
|
|
unsigned error = 0;
|
|
HuffmanTree tree_ll; /*the huffman tree for literal and length codes*/
|
|
HuffmanTree tree_d; /*the huffman tree for distance codes*/
|
|
size_t inbitlength = inlength * 8;
|
|
|
|
HuffmanTree_init(&tree_ll);
|
|
HuffmanTree_init(&tree_d);
|
|
|
|
if(btype == 1) getTreeInflateFixed(&tree_ll, &tree_d);
|
|
else if(btype == 2)
|
|
{
|
|
error = getTreeInflateDynamic(&tree_ll, &tree_d, in, bp, inlength);
|
|
}
|
|
|
|
for(;;) /*decode all symbols until end reached*/
|
|
{
|
|
/*code_ll is literal, length or end code*/
|
|
unsigned code_ll = huffmanDecodeSymbol(in, bp, &tree_ll, inbitlength);
|
|
if(code_ll <= 255) /*literal symbol*/
|
|
{
|
|
if((*pos) >= out->size)
|
|
{
|
|
/*reserve more room at once*/
|
|
if(!ucvector_resize(out, ((*pos) + 1) * 2)) ERROR_BREAK(9913 /*alloc fail*/);
|
|
}
|
|
out->data[(*pos)] = (unsigned char)(code_ll);
|
|
(*pos)++;
|
|
}
|
|
else if(code_ll >= FIRST_LENGTH_CODE_INDEX && code_ll <= LAST_LENGTH_CODE_INDEX) /*length code*/
|
|
{
|
|
unsigned code_d, distance;
|
|
unsigned numextrabits_l, numextrabits_d; /*extra bits for length and distance*/
|
|
size_t start, forward, backward, length;
|
|
|
|
/*part 1: get length base*/
|
|
length = LENGTHBASE[code_ll - FIRST_LENGTH_CODE_INDEX];
|
|
|
|
/*part 2: get extra bits and add the value of that to length*/
|
|
numextrabits_l = LENGTHEXTRA[code_ll - FIRST_LENGTH_CODE_INDEX];
|
|
if(((*bp) >> 3) >= inlength) ERROR_BREAK(51); /*error, bit pointer will jump past memory*/
|
|
length += readBitsFromStream(bp, in, numextrabits_l);
|
|
|
|
/*part 3: get distance code*/
|
|
code_d = huffmanDecodeSymbol(in, bp, &tree_d, inbitlength);
|
|
if(code_d > 29)
|
|
{
|
|
if(code_ll == (unsigned)(-1)) /*huffmanDecodeSymbol returns (unsigned)(-1) in case of error*/
|
|
{
|
|
/*return error code 10 or 11 depending on the situation that happened in huffmanDecodeSymbol
|
|
(10=no endcode, 11=wrong jump outside of tree)*/
|
|
error = (*bp) > inlength * 8 ? 10 : 11;
|
|
}
|
|
else error = 18; /*error: invalid distance code (30-31 are never used)*/
|
|
break;
|
|
}
|
|
distance = DISTANCEBASE[code_d];
|
|
|
|
/*part 4: get extra bits from distance*/
|
|
numextrabits_d = DISTANCEEXTRA[code_d];
|
|
if(((*bp) >> 3) >= inlength) ERROR_BREAK(51); /*error, bit pointer will jump past memory*/
|
|
|
|
distance += readBitsFromStream(bp, in, numextrabits_d);
|
|
|
|
/*part 5: fill in all the out[n] values based on the length and dist*/
|
|
start = (*pos);
|
|
backward = start - distance;
|
|
if((*pos) + length >= out->size)
|
|
{
|
|
/*reserve more room at once*/
|
|
if(!ucvector_resize(out, ((*pos) + length) * 2)) ERROR_BREAK(9914 /*alloc fail*/);
|
|
}
|
|
|
|
for(forward = 0; forward < length; forward++)
|
|
{
|
|
out->data[(*pos)] = out->data[backward];
|
|
(*pos)++;
|
|
backward++;
|
|
if(backward >= start) backward = start - distance;
|
|
}
|
|
}
|
|
else if(code_ll == 256)
|
|
{
|
|
break; /*end code, break the loop*/
|
|
}
|
|
else /*if(code == (unsigned)(-1))*/ /*huffmanDecodeSymbol returns (unsigned)(-1) in case of error*/
|
|
{
|
|
/*return error code 10 or 11 depending on the situation that happened in huffmanDecodeSymbol
|
|
(10=no endcode, 11=wrong jump outside of tree)*/
|
|
error = (*bp) > inlength * 8 ? 10 : 11;
|
|
break;
|
|
}
|
|
}
|
|
|
|
HuffmanTree_cleanup(&tree_ll);
|
|
HuffmanTree_cleanup(&tree_d);
|
|
|
|
return error;
|
|
}
|
|
|
|
static unsigned inflateNoCompression(ucvector* out, const unsigned char* in, size_t* bp, size_t* pos, size_t inlength)
|
|
{
|
|
/*go to first boundary of byte*/
|
|
size_t p;
|
|
unsigned LEN, NLEN, n, error = 0;
|
|
while(((*bp) & 0x7) != 0) (*bp)++;
|
|
p = (*bp) / 8; /*byte position*/
|
|
|
|
/*read LEN (2 bytes) and NLEN (2 bytes)*/
|
|
if(p >= inlength - 4) return 52; /*error, bit pointer will jump past memory*/
|
|
LEN = in[p] + 256 * in[p + 1]; p += 2;
|
|
NLEN = in[p] + 256 * in[p + 1]; p += 2;
|
|
|
|
/*check if 16-bit NLEN is really the one's complement of LEN*/
|
|
if(LEN + NLEN != 65535) return 21; /*error: NLEN is not one's complement of LEN*/
|
|
|
|
if((*pos) + LEN >= out->size)
|
|
{
|
|
if(!ucvector_resize(out, (*pos) + LEN)) return 9915; /*alloc fail*/
|
|
}
|
|
|
|
/*read the literal data: LEN bytes are now stored in the out buffer*/
|
|
if(p + LEN > inlength) return 23; /*error: reading outside of in buffer*/
|
|
for(n = 0; n < LEN; n++) out->data[(*pos)++] = in[p++];
|
|
|
|
(*bp) = p * 8;
|
|
|
|
return error;
|
|
}
|
|
|
|
/*inflate the deflated data (cfr. deflate spec); return value is the error*/
|
|
static unsigned LodePNG_inflate(ucvector* out, const unsigned char* in, size_t insize, size_t inpos)
|
|
{
|
|
/*bit pointer in the "in" data, current byte is bp >> 3, current bit is bp & 0x7 (from lsb to msb of the byte)*/
|
|
size_t bp = 0;
|
|
unsigned BFINAL = 0;
|
|
size_t pos = 0; /*byte position in the out buffer*/
|
|
|
|
unsigned error = 0;
|
|
|
|
while(!BFINAL)
|
|
{
|
|
unsigned BTYPE;
|
|
if(bp + 2 >= insize * 8) return 52; /*error, bit pointer will jump past memory*/
|
|
BFINAL = readBitFromStream(&bp, &in[inpos]);
|
|
BTYPE = 1 * readBitFromStream(&bp, &in[inpos]);
|
|
BTYPE += 2 * readBitFromStream(&bp, &in[inpos]);
|
|
|
|
if(BTYPE == 3) return 20; /*error: invalid BTYPE*/
|
|
else if(BTYPE == 0) error = inflateNoCompression(out, &in[inpos], &bp, &pos, insize); /*no compression*/
|
|
else error = inflateHuffmanBlock(out, &in[inpos], &bp, &pos, insize, BTYPE); /*compression, BTYPE 01 or 10*/
|
|
|
|
if(error) return error;
|
|
}
|
|
|
|
/*Only now we know the true size of out, resize it to that*/
|
|
if(!ucvector_resize(out, pos)) error = 9916; /*alloc fail*/
|
|
|
|
return error;
|
|
}
|
|
|
|
#endif /*LODEPNG_COMPILE_DECODER*/
|
|
|
|
#ifdef LODEPNG_COMPILE_ENCODER
|
|
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
/* / Deflator (Compressor) / */
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
|
|
static const size_t MAX_SUPPORTED_DEFLATE_LENGTH = 258;
|
|
|
|
/*bitlen is the size in bits of the code*/
|
|
static void addHuffmanSymbol(size_t* bp, ucvector* compressed, unsigned code, unsigned bitlen)
|
|
{
|
|
addBitsToStreamReversed(bp, compressed, code, bitlen);
|
|
}
|
|
|
|
/*search the index in the array, that has the largest value smaller than or equal to the given value,
|
|
given array must be sorted (if no value is smaller, it returns the size of the given array)*/
|
|
static size_t searchCodeIndex(const unsigned* array, size_t array_size, size_t value)
|
|
{
|
|
/*linear search implementation*/
|
|
/*for(size_t i = 1; i < array_size; i++) if(array[i] > value) return i - 1;
|
|
return array_size - 1;*/
|
|
|
|
/*binary search implementation (not that much faster) (precondition: array_size > 0)*/
|
|
size_t left = 1;
|
|
size_t right = array_size - 1;
|
|
while(left <= right)
|
|
{
|
|
size_t mid = (left + right) / 2;
|
|
if(array[mid] <= value) left = mid + 1; /*the value to find is more to the right*/
|
|
else if(array[mid - 1] > value) right = mid - 1; /*the value to find is more to the left*/
|
|
else return mid - 1;
|
|
}
|
|
return array_size - 1;
|
|
}
|
|
|
|
static void addLengthDistance(uivector* values, size_t length, size_t distance)
|
|
{
|
|
/*values in encoded vector are those used by deflate:
|
|
0-255: literal bytes
|
|
256: end
|
|
257-285: length/distance pair (length code, followed by extra length bits, distance code, extra distance bits)
|
|
286-287: invalid*/
|
|
|
|
unsigned length_code = (unsigned)searchCodeIndex(LENGTHBASE, 29, length);
|
|
unsigned extra_length = (unsigned)(length - LENGTHBASE[length_code]);
|
|
unsigned dist_code = (unsigned)searchCodeIndex(DISTANCEBASE, 30, distance);
|
|
unsigned extra_distance = (unsigned)(distance - DISTANCEBASE[dist_code]);
|
|
|
|
uivector_push_back(values, length_code + FIRST_LENGTH_CODE_INDEX);
|
|
uivector_push_back(values, extra_length);
|
|
uivector_push_back(values, dist_code);
|
|
uivector_push_back(values, extra_distance);
|
|
}
|
|
|
|
#if 0
|
|
/*the "brute force" version of the encodeLZ7 algorithm, not used anymore, kept here for reference*/
|
|
static unsigned encodeLZ77_brute(uivector* out, const unsigned char* in, size_t insize, unsigned windowSize)
|
|
{
|
|
size_t pos;
|
|
for(pos = 0; pos < insize; pos++)
|
|
{
|
|
size_t length = 0, offset = 0; /*the length and offset found for the current position*/
|
|
size_t max_offset = pos < windowSize ? pos : windowSize; /*how far back to test*/
|
|
size_t current_offset;
|
|
|
|
/**search for the longest string, backwards through all possible distances (=offsets)**/
|
|
for(current_offset = 1; current_offset < max_offset; current_offset++)
|
|
{
|
|
size_t backpos = pos - current_offset;
|
|
if(in[backpos] == in[pos])
|
|
{
|
|
/*test the next characters*/
|
|
size_t current_length = 1;
|
|
size_t backtest = backpos + 1;
|
|
size_t foretest = pos + 1;
|
|
/*maximum supporte length by deflate is max length*/
|
|
while(foretest < insize && in[backtest] == in[foretest] && current_length < MAX_SUPPORTED_DEFLATE_LENGTH)
|
|
{
|
|
if(backpos >= pos)
|
|
{
|
|
/*continue as if we work on the decoded bytes after pos by jumping back before pos*/
|
|
backpos -= current_offset;
|
|
}
|
|
current_length++;
|
|
backtest++;
|
|
foretest++;
|
|
}
|
|
if(current_length > length)
|
|
{
|
|
length = current_length; /*the longest length*/
|
|
offset = current_offset; /*the offset that is related to this longest length*/
|
|
/*you can jump out of this for loop once a length of max length is found (gives significant speed gain)*/
|
|
if(current_length == MAX_SUPPORTED_DEFLATE_LENGTH) break;
|
|
}
|
|
}
|
|
}
|
|
|
|
/**encode it as length/distance pair or literal value**/
|
|
if(length < 3) /*only lengths of 3 or higher are supported as length/distance pair*/
|
|
{
|
|
uivector_push_back(out, in[pos]);
|
|
}
|
|
else
|
|
{
|
|
addLengthDistance(out, length, offset);
|
|
pos += (length - 1);
|
|
}
|
|
} /*end of the loop through each character of input*/
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
static const unsigned HASH_NUM_VALUES = 2048;
|
|
static const unsigned HASH_NUM_CHARACTERS = 3;
|
|
static const unsigned HASH_SHIFT = 2;
|
|
/*
|
|
The HASH_NUM_CHARACTERS value is used to make encoding faster by using longer
|
|
sequences to generate a hash value from the stream bytes. Setting it to 3
|
|
gives exactly the same compression as the brute force method, since deflate's
|
|
run length encoding starts with lengths of 3. Setting it to higher values,
|
|
like 6, can make the encoding faster (not always though!), but will cause the
|
|
encoding to miss any length between 3 and this value, so that the compression
|
|
may be worse (but this can vary too depending on the image, sometimes it is
|
|
even a bit better instead).
|
|
The HASH_NUM_VALUES is the amount of unique possible hash values that
|
|
combinations of bytes can give, the higher it is the more memory is needed, but
|
|
if it's too low the advantage of hashing is gone.
|
|
*/
|
|
|
|
static unsigned getHash(const unsigned char* data, size_t size, size_t pos, size_t num)
|
|
{
|
|
unsigned result = 0;
|
|
size_t amount, i;
|
|
if(pos >= size) return 0;
|
|
amount = num;
|
|
if(pos + amount >= size) amount = size - pos;
|
|
for(i = 0; i < amount; i++) result ^= (data[pos + i] << (i * HASH_SHIFT));
|
|
return result % HASH_NUM_VALUES;
|
|
}
|
|
|
|
static unsigned countInitialZeros(const unsigned char* data, size_t size, size_t pos)
|
|
{
|
|
size_t max_count = MAX_SUPPORTED_DEFLATE_LENGTH;
|
|
size_t i;
|
|
if(max_count > size - pos) max_count = size - pos;
|
|
for(i = 0; i < max_count; i++)
|
|
{
|
|
if(data[pos + i] != 0)
|
|
return i;
|
|
}
|
|
return max_count;
|
|
}
|
|
|
|
/*push a value to the vector in a circular way. This is to do as if we're extending
|
|
the vector's size forever, but instead the size is limited to maxsize and it wraps
|
|
around, to avoid too large memory size. The pos pointer gets updated to the current
|
|
end (unless updatepos is false, in that case pos is only used to know the current
|
|
value). returns 1 on success, 0 if fail*/
|
|
static unsigned push_circular(uivector* v, unsigned* pos, unsigned value, size_t maxsize, unsigned updatepos)
|
|
{
|
|
if(v->size < maxsize)
|
|
{
|
|
if(!uivector_push_back(v, value)) return 0;
|
|
if(updatepos) (*pos)++;
|
|
}
|
|
else
|
|
{
|
|
if(updatepos)
|
|
{
|
|
(*pos)++;
|
|
if((*pos) > maxsize) (*pos) = 1;
|
|
}
|
|
v->data[(*pos) - 1] = value;
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
/*Enable to use lazy instead of greedy matghing. It looks one byte further
|
|
to see if that one gives a longer distance. This gives slightly better compression, at the cost
|
|
of a speed loss.*/
|
|
#define LAZY_MATCHING
|
|
|
|
/*
|
|
LZ77-encode the data. Return value is error code. The input are raw bytes, the output
|
|
is in the form of unsigned integers with codes representing for example literal bytes, or
|
|
length/distance pairs.
|
|
It uses a hash table technique to let it encode faster. When doing LZ77 encoding, a
|
|
sliding window (of windowSize) is used, and all past bytes in that window can be used as
|
|
the "dictionary". A brute force search through all possible distances would be slow, and
|
|
this hash technique is one out of several ways to speed this up.
|
|
*/
|
|
static unsigned encodeLZ77(uivector* out, const unsigned char* in, size_t insize, unsigned windowSize)
|
|
{
|
|
/**generate hash table**/
|
|
/*
|
|
The hash table is 2-dimensional. For every possible hash value, it contains a list of positions
|
|
in the data where this hash occured.
|
|
tablepos1 and tablepos2 remember the last used start and end index in the hash table for each hash value.
|
|
*/
|
|
vector table; /*HASH_NUM_VALUES uivectors; this is what would be an std::vector<std::vector<unsigned> > in C++*/
|
|
uivector tablepos1, tablepos2;
|
|
/*hash 0 indicates a possible common case of a long sequence of zeros, store and use the amount here for a speedup*/
|
|
uivector initialZerosTable;
|
|
unsigned pos, i, error = 0;
|
|
unsigned hash_num_characters = HASH_NUM_CHARACTERS;
|
|
|
|
vector_init(&table, sizeof(uivector));
|
|
if(!vector_resize(&table, HASH_NUM_VALUES)) return 9917; /*alloc fail*/
|
|
for(i = 0; i < HASH_NUM_VALUES; i++)
|
|
{
|
|
uivector* v = (uivector*)vector_get(&table, i);
|
|
uivector_init(v);
|
|
}
|
|
|
|
/*remember start and end positions in the tables to search in*/
|
|
uivector_init(&tablepos1);
|
|
uivector_init(&tablepos2);
|
|
uivector_init(&initialZerosTable);
|
|
|
|
if(!uivector_resizev(&tablepos1, HASH_NUM_VALUES, 0)) error = 9918; /*alloc fail*/
|
|
if(!uivector_resizev(&tablepos2, HASH_NUM_VALUES, 0)) error = 9919; /*alloc fail*/
|
|
|
|
if(!error)
|
|
{
|
|
unsigned offset, max_offset; /*the offset represents the distance in LZ77 terminology*/
|
|
unsigned length, tablepos;
|
|
#ifdef LAZY_MATCHING
|
|
unsigned lazy = 0;
|
|
unsigned lazylength, lazyoffset;
|
|
#endif /*LAZY_MATCHING*/
|
|
unsigned hash, initialZeros = 0;
|
|
unsigned backpos, current_offset, t1, t2, t11, current_length;
|
|
const unsigned char *lastptr, *foreptr, *backptr;
|
|
uivector* v; /*vector from the hash table we're currently working on*/
|
|
unsigned hashWindow = windowSize;
|
|
unsigned numones = 0;
|
|
|
|
for(pos = 0; pos < insize; pos++)
|
|
{
|
|
length = 0, offset = 0; /*the length and offset found for the current position*/
|
|
max_offset = pos < windowSize ? pos : windowSize; /*how far back to test*/
|
|
|
|
/*search for the longest string. First find out where in the table to start
|
|
(the first value that is in the range from "pos - max_offset" to "pos")*/
|
|
hash = getHash(in, insize, pos, hash_num_characters);
|
|
v = (uivector*)vector_get(&table, hash);
|
|
if(!push_circular(v, &tablepos2.data[hash], pos, hashWindow, 1)) ERROR_BREAK(9920 /*alloc fail*/);
|
|
|
|
if(hash == 0)
|
|
{
|
|
initialZeros = countInitialZeros(in, insize, pos);
|
|
if(!push_circular(&initialZerosTable, &tablepos2.data[hash], initialZeros, hashWindow, 0))
|
|
ERROR_BREAK(9920 /*alloc fail*/);
|
|
}
|
|
|
|
while(v->data[tablepos1.data[hash]] < pos - max_offset)
|
|
{
|
|
/*it now points to the first value in the table for which the index is
|
|
larger than or equal to pos - max_offset*/
|
|
tablepos1.data[hash]++;
|
|
if(tablepos1.data[hash] >= hashWindow) tablepos1.data[hash] = 0;
|
|
}
|
|
|
|
t1 = tablepos1.data[hash];
|
|
t2 = tablepos2.data[hash] - 1;
|
|
if(tablepos2.data[hash] == 0) t2 = hashWindow - 1;
|
|
|
|
lastptr = &in[insize < pos + MAX_SUPPORTED_DEFLATE_LENGTH ? insize : pos + MAX_SUPPORTED_DEFLATE_LENGTH];
|
|
|
|
t11 = t1 == 0 ? hashWindow - 1 : t1 - 1;
|
|
for(tablepos = t2 == 0 ? hashWindow - 1 : t2 - 1;
|
|
tablepos != t2 && tablepos != t11 && tablepos < v->size;
|
|
tablepos = tablepos == 0 ? hashWindow - 1 : tablepos - 1)
|
|
{
|
|
backpos = v->data[tablepos];
|
|
current_offset = pos - backpos;
|
|
/*test the next characters*/
|
|
foreptr = &in[pos];
|
|
backptr = &in[backpos];
|
|
|
|
if(hash == 0)
|
|
{
|
|
unsigned skip = initialZerosTable.data[tablepos];
|
|
if(skip > initialZeros) skip = initialZeros;
|
|
if(skip > insize - pos) skip = insize - pos;
|
|
backptr += skip;
|
|
foreptr += skip;
|
|
}
|
|
while(foreptr != lastptr && *backptr == *foreptr) /*maximum supported length by deflate is max length*/
|
|
{
|
|
++backptr;
|
|
++foreptr;
|
|
}
|
|
current_length = (unsigned)(foreptr - &in[pos]);
|
|
if(current_length > length)
|
|
{
|
|
length = current_length; /*the longest length*/
|
|
offset = current_offset; /*the offset that is related to this longest length*/
|
|
/*you can jump out of this for loop once a length of max length is found (gives significant speed gain)*/
|
|
if(current_length == MAX_SUPPORTED_DEFLATE_LENGTH) break;
|
|
}
|
|
}
|
|
|
|
#ifdef LAZY_MATCHING
|
|
if(!lazy && length >= 3 && length < MAX_SUPPORTED_DEFLATE_LENGTH)
|
|
{
|
|
lazylength = length;
|
|
lazyoffset = offset;
|
|
lazy = 1;
|
|
continue;
|
|
}
|
|
if(lazy)
|
|
{
|
|
if(pos == 0) ERROR_BREAK(81);
|
|
lazy = 0;
|
|
if(length > lazylength + 1)
|
|
{
|
|
/*push the previous character as literal*/
|
|
if(!uivector_push_back(out, in[pos - 1])) ERROR_BREAK(9921 /*alloc fail*/);
|
|
}
|
|
else
|
|
{
|
|
length = lazylength;
|
|
offset = lazyoffset;
|
|
pos--;
|
|
}
|
|
}
|
|
#endif /*LAZY_MATCHING*/
|
|
|
|
/**encode it as length/distance pair or literal value**/
|
|
if(length < 3) /*only lengths of 3 or higher are supported as length/distance pair*/
|
|
{
|
|
if(!uivector_push_back(out, in[pos])) ERROR_BREAK(9921 /*alloc fail*/);
|
|
}
|
|
else
|
|
{
|
|
unsigned j, local_hash;
|
|
addLengthDistance(out, length, offset);
|
|
for(j = 0; j < length - 1; j++)
|
|
{
|
|
unsigned* t2p; /*pointer to current tablepos2 element*/
|
|
pos++;
|
|
local_hash = getHash(in, insize, pos, hash_num_characters);
|
|
t2p = &tablepos2.data[local_hash];
|
|
v = (uivector*)vector_get(&table, local_hash);
|
|
if(!push_circular(v, t2p, pos, hashWindow, 1)) ERROR_BREAK(9920 /*alloc fail*/);
|
|
|
|
if(local_hash == 0)
|
|
{
|
|
initialZeros = countInitialZeros(in, insize, pos);
|
|
if(!push_circular(&initialZerosTable, t2p, initialZeros, hashWindow, 0))
|
|
ERROR_BREAK(9922 /*alloc fail*/);
|
|
}
|
|
if(local_hash == 1 && hash_num_characters == 3)
|
|
{
|
|
/*
|
|
If many hash values are getting grouped together in hash value 1, 4, 16, 20, ...,
|
|
it indicates there are many near-zero values. This is not zero enough to benefit from a speed
|
|
increase from the initialZerosTable, and makes it very slow. For that case only, switch to
|
|
hash_num_characters = 6. Value 6 is experimentally found to be fastest. For this particular type
|
|
of file, the compression isn't even worse, despite the fact that lengths < 6 are now no longer
|
|
found, and that by changing hash_num_characters not all previously found hash values are still valid.
|
|
Almost all images compress fast enough and smaller with hash_num_characters = 3, except sine plasma
|
|
images. Those benefit a lot from this heuristic.
|
|
*/
|
|
if(numones > 8192 && numones > pos / 16) hash_num_characters = 6;
|
|
else numones++;
|
|
}
|
|
}
|
|
}
|
|
} /*end of the loop through each character of input*/
|
|
} /*end of "if(!error)"*/
|
|
|
|
/*cleanup*/
|
|
for(i = 0; i < table.size; i++)
|
|
{
|
|
uivector* v = (uivector*)vector_get(&table, i);
|
|
uivector_cleanup(v);
|
|
}
|
|
vector_cleanup(&table);
|
|
uivector_cleanup(&tablepos1);
|
|
uivector_cleanup(&tablepos2);
|
|
uivector_cleanup(&initialZerosTable);
|
|
return error;
|
|
}
|
|
|
|
/* /////////////////////////////////////////////////////////////////////////// */
|
|
|
|
static unsigned deflateNoCompression(ucvector* out, const unsigned char* data, size_t datasize)
|
|
{
|
|
/*non compressed deflate block data: 1 bit BFINAL,2 bits BTYPE,(5 bits): it jumps to start of next byte,
|
|
2 bytes LEN, 2 bytes NLEN, LEN bytes literal DATA*/
|
|
|
|
size_t i, j, numdeflateblocks = datasize / 65536 + 1;
|
|
unsigned datapos = 0;
|
|
for(i = 0; i < numdeflateblocks; i++)
|
|
{
|
|
unsigned BFINAL, BTYPE, LEN, NLEN;
|
|
unsigned char firstbyte;
|
|
|
|
BFINAL = (i == numdeflateblocks - 1);
|
|
BTYPE = 0;
|
|
|
|
firstbyte = (unsigned char)(BFINAL + ((BTYPE & 1) << 1) + ((BTYPE & 2) << 1));
|
|
ucvector_push_back(out, firstbyte);
|
|
|
|
LEN = 65535;
|
|
if(datasize - datapos < 65535) LEN = (unsigned)datasize - datapos;
|
|
NLEN = 65535 - LEN;
|
|
|
|
ucvector_push_back(out, (unsigned char)(LEN % 256));
|
|
ucvector_push_back(out, (unsigned char)(LEN / 256));
|
|
ucvector_push_back(out, (unsigned char)(NLEN % 256));
|
|
ucvector_push_back(out, (unsigned char)(NLEN / 256));
|
|
|
|
/*Decompressed data*/
|
|
for(j = 0; j < 65535 && datapos < datasize; j++)
|
|
{
|
|
ucvector_push_back(out, data[datapos++]);
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
write the lz77-encoded data, which has lit, len and dist codes, to compressed stream using huffman trees.
|
|
tree_ll: the tree for lit and len codes.
|
|
tree_d: the tree for distance codes.
|
|
*/
|
|
static void writeLZ77data(size_t* bp, ucvector* out, const uivector* lz77_encoded,
|
|
const HuffmanTree* tree_ll, const HuffmanTree* tree_d)
|
|
{
|
|
size_t i = 0;
|
|
for(i = 0; i < lz77_encoded->size; i++)
|
|
{
|
|
unsigned val = lz77_encoded->data[i];
|
|
addHuffmanSymbol(bp, out, HuffmanTree_getCode(tree_ll, val), HuffmanTree_getLength(tree_ll, val));
|
|
if(val > 256) /*for a length code, 3 more things have to be added*/
|
|
{
|
|
unsigned length_index = val - FIRST_LENGTH_CODE_INDEX;
|
|
unsigned n_length_extra_bits = LENGTHEXTRA[length_index];
|
|
unsigned length_extra_bits = lz77_encoded->data[++i];
|
|
|
|
unsigned distance_code = lz77_encoded->data[++i];
|
|
|
|
unsigned distance_index = distance_code;
|
|
unsigned n_distance_extra_bits = DISTANCEEXTRA[distance_index];
|
|
unsigned distance_extra_bits = lz77_encoded->data[++i];
|
|
|
|
addBitsToStream(bp, out, length_extra_bits, n_length_extra_bits);
|
|
addHuffmanSymbol(bp, out, HuffmanTree_getCode(tree_d, distance_code),
|
|
HuffmanTree_getLength(tree_d, distance_code));
|
|
addBitsToStream(bp, out, distance_extra_bits, n_distance_extra_bits);
|
|
}
|
|
}
|
|
}
|
|
|
|
/*Deflate for a block of type "dynamic", that is, with freely, optimally, created huffman trees*/
|
|
static unsigned deflateDynamic(ucvector* out, const unsigned char* data, size_t datasize,
|
|
const LodePNG_CompressSettings* settings)
|
|
{
|
|
unsigned error = 0;
|
|
|
|
/*
|
|
A block is compressed as follows: The PNG data is lz77 encoded, resulting in
|
|
literal bytes and length/distance pairs. This is then huffman compressed with
|
|
two huffman trees. One huffman tree is used for the lit and len values ("ll"),
|
|
another huffman tree is used for the dist values ("d"). These two trees are
|
|
stored using their code lengths, and to compress even more these code lengths
|
|
are also run-length encoded and huffman compressed. This gives a huffman tree
|
|
of code lengths "cl". The code lenghts used to describe this third tree are
|
|
the code length code lengths ("clcl").
|
|
*/
|
|
|
|
/*The lz77 encoded data, represented with integers since there will also be length and distance codes in it*/
|
|
uivector lz77_encoded;
|
|
HuffmanTree tree_ll; /*tree for lit,len values*/
|
|
HuffmanTree tree_d; /*tree for distance codes*/
|
|
HuffmanTree tree_cl; /*tree for encoding the code lengths representing tree_ll and tree_d*/
|
|
uivector frequencies_ll; /*frequency of lit,len codes*/
|
|
uivector frequencies_d; /*frequency of dist codes*/
|
|
uivector frequencies_cl; /*frequency of code length codes*/
|
|
uivector bitlen_lld; /*lit,len,dist code lenghts (int bits), literally (without repeat codes).*/
|
|
uivector bitlen_lld_e; /*bitlen_lld encoded with repeat codes (this is a rudemtary run length compression)*/
|
|
/*bitlen_cl is the code length code lengths ("clcl"). The bit lengths of codes to represent tree_cl
|
|
(these are written as is in the file, it would be crazy to compress these using yet another huffman
|
|
tree that needs to be represented by yet another set of code lengths)*/
|
|
uivector bitlen_cl;
|
|
|
|
/*
|
|
Due to the huffman compression of huffman tree representations ("two levels"), there are some anologies:
|
|
bitlen_lld is to tree_cl what data is to tree_ll and tree_d.
|
|
bitlen_lld_e is to bitlen_lld what lz77_encoded is to data.
|
|
bitlen_cl is to bitlen_lld_e what bitlen_lld is to lz77_encoded.
|
|
*/
|
|
|
|
unsigned BFINAL = 1; /*make only one block... the first and final one*/
|
|
size_t numcodes_ll, numcodes_d, i;
|
|
size_t bp = 0; /*the bit pointer*/
|
|
unsigned HLIT, HDIST, HCLEN;
|
|
|
|
uivector_init(&lz77_encoded);
|
|
HuffmanTree_init(&tree_ll);
|
|
HuffmanTree_init(&tree_d);
|
|
HuffmanTree_init(&tree_cl);
|
|
uivector_init(&frequencies_ll);
|
|
uivector_init(&frequencies_d);
|
|
uivector_init(&frequencies_cl);
|
|
uivector_init(&bitlen_lld);
|
|
uivector_init(&bitlen_lld_e);
|
|
uivector_init(&bitlen_cl);
|
|
|
|
/*This while loop is never loops due to a break at the end, it is here to
|
|
allow breaking out of it to the cleanup phase on error conditions.*/
|
|
while(!error)
|
|
{
|
|
if(settings->useLZ77)
|
|
{
|
|
error = encodeLZ77(&lz77_encoded, data, datasize, settings->windowSize); /*LZ77 encoded*/
|
|
if(error) break;
|
|
}
|
|
else
|
|
{
|
|
if(!uivector_resize(&lz77_encoded, datasize)) ERROR_BREAK(9923 /*alloc fail*/);
|
|
for(i = 0; i < datasize; i++) lz77_encoded.data[i] = data[i]; /*no LZ77, but still will be Huffman compressed*/
|
|
}
|
|
|
|
if(!uivector_resizev(&frequencies_ll, 286, 0)) ERROR_BREAK(9924 /*alloc fail*/);
|
|
if(!uivector_resizev(&frequencies_d, 30, 0)) ERROR_BREAK(9925 /*alloc fail*/);
|
|
|
|
/*Count the frequencies of lit, len and dist codes*/
|
|
for(i = 0; i < lz77_encoded.size; i++)
|
|
{
|
|
unsigned symbol = lz77_encoded.data[i];
|
|
frequencies_ll.data[symbol]++;
|
|
if(symbol > 256)
|
|
{
|
|
unsigned dist = lz77_encoded.data[i + 2];
|
|
frequencies_d.data[dist]++;
|
|
i += 3;
|
|
}
|
|
}
|
|
frequencies_ll.data[256] = 1; /*there will be exactly 1 end code, at the end of the block*/
|
|
|
|
/*Make both huffman trees, one for the lit and len codes, one for the dist codes*/
|
|
error = HuffmanTree_makeFromFrequencies(&tree_ll, frequencies_ll.data, frequencies_ll.size, 15);
|
|
if(error) break;
|
|
error = HuffmanTree_makeFromFrequencies(&tree_d, frequencies_d.data, frequencies_d.size, 15);
|
|
if(error) break;
|
|
|
|
numcodes_ll = tree_ll.numcodes; if(numcodes_ll > 286) numcodes_ll = 286;
|
|
numcodes_d = tree_d.numcodes; if(numcodes_d > 30) numcodes_d = 30;
|
|
/*store the code lengths of both generated trees in bitlen_lld*/
|
|
for(i = 0; i < numcodes_ll; i++) uivector_push_back(&bitlen_lld, HuffmanTree_getLength(&tree_ll, (unsigned)i));
|
|
for(i = 0; i < numcodes_d; i++) uivector_push_back(&bitlen_lld, HuffmanTree_getLength(&tree_d, (unsigned)i));
|
|
|
|
/*run-length compress bitlen_ldd into bitlen_lld_e by using repeat codes 16 (copy length 3-6 times),
|
|
17 (3-10 zeroes), 18 (11-138 zeroes)*/
|
|
for(i = 0; i < (unsigned)bitlen_lld.size; i++)
|
|
{
|
|
unsigned j = 0; /*amount of repititions*/
|
|
while(i + j + 1 < (unsigned)bitlen_lld.size && bitlen_lld.data[i + j + 1] == bitlen_lld.data[i]) j++;
|
|
|
|
if(bitlen_lld.data[i] == 0 && j >= 2) /*repeat code for zeroes*/
|
|
{
|
|
j++; /*include the first zero*/
|
|
if(j <= 10) /*repeat code 17 supports max 10 zeroes*/
|
|
{
|
|
uivector_push_back(&bitlen_lld_e, 17);
|
|
uivector_push_back(&bitlen_lld_e, j - 3);
|
|
}
|
|
else /*repeat code 18 supports max 138 zeroes*/
|
|
{
|
|
if(j > 138) j = 138;
|
|
uivector_push_back(&bitlen_lld_e, 18);
|
|
uivector_push_back(&bitlen_lld_e, j - 11);
|
|
}
|
|
i += (j - 1);
|
|
}
|
|
else if(j >= 3) /*repeat code for value other than zero*/
|
|
{
|
|
size_t k;
|
|
unsigned num = j / 6, rest = j % 6;
|
|
uivector_push_back(&bitlen_lld_e, bitlen_lld.data[i]);
|
|
for(k = 0; k < num; k++)
|
|
{
|
|
uivector_push_back(&bitlen_lld_e, 16);
|
|
uivector_push_back(&bitlen_lld_e, 6 - 3);
|
|
}
|
|
if(rest >= 3)
|
|
{
|
|
uivector_push_back(&bitlen_lld_e, 16);
|
|
uivector_push_back(&bitlen_lld_e, rest - 3);
|
|
}
|
|
else j -= rest;
|
|
i += j;
|
|
}
|
|
else /*too short to benefit from repeat code*/
|
|
{
|
|
uivector_push_back(&bitlen_lld_e, bitlen_lld.data[i]);
|
|
}
|
|
}
|
|
|
|
/*generate tree_cl, the huffmantree of huffmantrees*/
|
|
|
|
if(!uivector_resizev(&frequencies_cl, NUM_CODE_LENGTH_CODES, 0)) ERROR_BREAK(9926 /*alloc fail*/);
|
|
for(i = 0; i < bitlen_lld_e.size; i++)
|
|
{
|
|
frequencies_cl.data[bitlen_lld_e.data[i]]++;
|
|
/*after a repeat code come the bits that specify the number of repetitions,
|
|
those don't need to be in the frequencies_cl calculation*/
|
|
if(bitlen_lld_e.data[i] >= 16) i++;
|
|
}
|
|
|
|
error = HuffmanTree_makeFromFrequencies(&tree_cl, frequencies_cl.data, frequencies_cl.size, 7);
|
|
if(error) break;
|
|
|
|
if(!uivector_resize(&bitlen_cl, NUM_CODE_LENGTH_CODES)) ERROR_BREAK(9927 /*alloc fail*/);
|
|
for(i = 0; i < NUM_CODE_LENGTH_CODES; i++)
|
|
{
|
|
/*lenghts of code length tree is in the order as specified by deflate*/
|
|
bitlen_cl.data[i] = HuffmanTree_getLength(&tree_cl, CLCL_ORDER[i]);
|
|
}
|
|
while(bitlen_cl.data[bitlen_cl.size - 1] == 0 && bitlen_cl.size > 4)
|
|
{
|
|
/*remove zeros at the end, but minimum size must be 4*/
|
|
if(!uivector_resize(&bitlen_cl, bitlen_cl.size - 1)) ERROR_BREAK(9928 /*alloc fail*/);
|
|
}
|
|
if(error) break;
|
|
|
|
/*
|
|
Write everything into the output
|
|
|
|
After the BFINAL and BTYPE, the dynamic block consists out of the following:
|
|
- 5 bits HLIT, 5 bits HDIST, 4 bits HCLEN
|
|
- (HCLEN+4)*3 bits code lengths of code length alphabet
|
|
- HLIT + 257 code lenghts of lit/length alphabet (encoded using the code length
|
|
alphabet, + possible repetition codes 16, 17, 18)
|
|
- HDIST + 1 code lengths of distance alphabet (encoded using the code length
|
|
alphabet, + possible repetition codes 16, 17, 18)
|
|
- compressed data
|
|
- 256 (end code)
|
|
*/
|
|
|
|
/*Write block type*/
|
|
addBitToStream(&bp, out, BFINAL);
|
|
addBitToStream(&bp, out, 0); /*first bit of BTYPE "dynamic"*/
|
|
addBitToStream(&bp, out, 1); /*second bit of BTYPE "dynamic"*/
|
|
|
|
/*write the HLIT, HDIST and HCLEN values*/
|
|
HLIT = (unsigned)(numcodes_ll - 257);
|
|
HDIST = (unsigned)(numcodes_d - 1);
|
|
HCLEN = (unsigned)bitlen_cl.size - 4;
|
|
addBitsToStream(&bp, out, HLIT, 5);
|
|
addBitsToStream(&bp, out, HDIST, 5);
|
|
addBitsToStream(&bp, out, HCLEN, 4);
|
|
|
|
/*write the code lenghts of the code length alphabet*/
|
|
for(i = 0; i < HCLEN + 4; i++) addBitsToStream(&bp, out, bitlen_cl.data[i], 3);
|
|
|
|
/*write the lenghts of the lit/len AND the dist alphabet*/
|
|
for(i = 0; i < bitlen_lld_e.size; i++)
|
|
{
|
|
addHuffmanSymbol(&bp, out, HuffmanTree_getCode(&tree_cl, bitlen_lld_e.data[i]),
|
|
HuffmanTree_getLength(&tree_cl, bitlen_lld_e.data[i]));
|
|
/*extra bits of repeat codes*/
|
|
if(bitlen_lld_e.data[i] == 16) addBitsToStream(&bp, out, bitlen_lld_e.data[++i], 2);
|
|
else if(bitlen_lld_e.data[i] == 17) addBitsToStream(&bp, out, bitlen_lld_e.data[++i], 3);
|
|
else if(bitlen_lld_e.data[i] == 18) addBitsToStream(&bp, out, bitlen_lld_e.data[++i], 7);
|
|
}
|
|
|
|
/*write the compressed data symbols*/
|
|
writeLZ77data(&bp, out, &lz77_encoded, &tree_ll, &tree_d);
|
|
/*error: the length of the end code 256 must be larger than 0*/
|
|
if(HuffmanTree_getLength(&tree_ll, 256) == 0) ERROR_BREAK(64);
|
|
|
|
/*write the end code*/
|
|
addHuffmanSymbol(&bp, out, HuffmanTree_getCode(&tree_ll, 256), HuffmanTree_getLength(&tree_ll, 256));
|
|
|
|
break; /*end of error-while*/
|
|
}
|
|
|
|
/*cleanup*/
|
|
uivector_cleanup(&lz77_encoded);
|
|
HuffmanTree_cleanup(&tree_ll);
|
|
HuffmanTree_cleanup(&tree_d);
|
|
HuffmanTree_cleanup(&tree_cl);
|
|
uivector_cleanup(&frequencies_ll);
|
|
uivector_cleanup(&frequencies_d);
|
|
uivector_cleanup(&frequencies_cl);
|
|
uivector_cleanup(&bitlen_lld_e);
|
|
uivector_cleanup(&bitlen_lld);
|
|
uivector_cleanup(&bitlen_cl);
|
|
|
|
return error;
|
|
}
|
|
|
|
static unsigned deflateFixed(ucvector* out, const unsigned char* data,
|
|
size_t datasize, const LodePNG_CompressSettings* settings)
|
|
{
|
|
HuffmanTree tree_ll; /*tree for literal values and length codes*/
|
|
HuffmanTree tree_d; /*tree for distance codes*/
|
|
|
|
unsigned BFINAL = 1; /*make only one block... the first and final one*/
|
|
unsigned error = 0;
|
|
size_t i, bp = 0; /*the bit pointer*/
|
|
|
|
HuffmanTree_init(&tree_ll);
|
|
HuffmanTree_init(&tree_d);
|
|
|
|
generateFixedLitLenTree(&tree_ll);
|
|
generateFixedDistanceTree(&tree_d);
|
|
|
|
addBitToStream(&bp, out, BFINAL);
|
|
addBitToStream(&bp, out, 1); /*first bit of BTYPE*/
|
|
addBitToStream(&bp, out, 0); /*second bit of BTYPE*/
|
|
|
|
if(settings->useLZ77) /*LZ77 encoded*/
|
|
{
|
|
uivector lz77_encoded;
|
|
uivector_init(&lz77_encoded);
|
|
error = encodeLZ77(&lz77_encoded, data, datasize, settings->windowSize);
|
|
if(!error) writeLZ77data(&bp, out, &lz77_encoded, &tree_ll, &tree_d);
|
|
uivector_cleanup(&lz77_encoded);
|
|
}
|
|
else /*no LZ77, but still will be Huffman compressed*/
|
|
{
|
|
for(i = 0; i < datasize; i++)
|
|
{
|
|
addHuffmanSymbol(&bp, out, HuffmanTree_getCode(&tree_ll, data[i]), HuffmanTree_getLength(&tree_ll, data[i]));
|
|
}
|
|
}
|
|
/*add END code*/
|
|
if(!error) addHuffmanSymbol(&bp, out, HuffmanTree_getCode(&tree_ll, 256), HuffmanTree_getLength(&tree_ll, 256));
|
|
|
|
/*cleanup*/
|
|
HuffmanTree_cleanup(&tree_ll);
|
|
HuffmanTree_cleanup(&tree_d);
|
|
|
|
return error;
|
|
}
|
|
|
|
static unsigned LodePNG_deflate(ucvector* out, const unsigned char* data, size_t datasize,
|
|
const LodePNG_CompressSettings* settings)
|
|
{
|
|
unsigned error = 0;
|
|
if(settings->btype == 0) error = deflateNoCompression(out, data, datasize);
|
|
else if(settings->btype == 1) error = deflateFixed(out, data, datasize, settings);
|
|
else if(settings->btype == 2) error = deflateDynamic(out, data, datasize, settings);
|
|
else error = 61;
|
|
return error;
|
|
}
|
|
|
|
#endif /*LODEPNG_COMPILE_DECODER*/
|
|
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
/* / Adler32 */
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
|
|
static unsigned update_adler32(unsigned adler, const unsigned char* data, unsigned len)
|
|
{
|
|
unsigned s1 = adler & 0xffff;
|
|
unsigned s2 = (adler >> 16) & 0xffff;
|
|
|
|
while(len > 0)
|
|
{
|
|
/*at least 5550 sums can be done before the sums overflow, saving a lot of module divisions*/
|
|
unsigned amount = len > 5550 ? 5550 : len;
|
|
len -= amount;
|
|
while(amount > 0)
|
|
{
|
|
s1 = (s1 + *data++);
|
|
s2 = (s2 + s1);
|
|
amount--;
|
|
}
|
|
s1 %= 65521;
|
|
s2 %= 65521;
|
|
}
|
|
|
|
return (s2 << 16) | s1;
|
|
}
|
|
|
|
/*Return the adler32 of the bytes data[0..len-1]*/
|
|
static unsigned adler32(const unsigned char* data, unsigned len)
|
|
{
|
|
return update_adler32(1L, data, len);
|
|
}
|
|
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
/* / Zlib / */
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
|
|
#ifdef LODEPNG_COMPILE_DECODER
|
|
|
|
unsigned LodePNG_zlib_decompress(unsigned char** out, size_t* outsize, const unsigned char* in,
|
|
size_t insize, const LodePNG_DecompressSettings* settings)
|
|
{
|
|
unsigned error = 0;
|
|
unsigned CM, CINFO, FDICT;
|
|
ucvector outv;
|
|
|
|
if(insize < 2) return 53; /*error, size of zlib data too small*/
|
|
/*read information from zlib header*/
|
|
if((in[0] * 256 + in[1]) % 31 != 0)
|
|
{
|
|
/*error: 256 * in[0] + in[1] must be a multiple of 31, the FCHECK value is supposed to be made that way*/
|
|
return 24;
|
|
}
|
|
|
|
CM = in[0] & 15;
|
|
CINFO = (in[0] >> 4) & 15;
|
|
/*FCHECK = in[1] & 31;*/ /*FCHECK is already tested above*/
|
|
FDICT = (in[1] >> 5) & 1;
|
|
/*FLEVEL = (in[1] >> 6) & 3;*/ /*FLEVEL is not used here*/
|
|
|
|
if(CM != 8 || CINFO > 7)
|
|
{
|
|
/*error: only compression method 8: inflate with sliding window of 32k is supported by the PNG spec*/
|
|
return 25;
|
|
}
|
|
if(FDICT != 0)
|
|
{
|
|
/*error: the specification of PNG says about the zlib stream:
|
|
"The additional flags shall not specify a preset dictionary."*/
|
|
return 26;
|
|
}
|
|
|
|
/*ucvector-controlled version of the output buffer, for dynamic array*/
|
|
ucvector_init_buffer(&outv, *out, *outsize);
|
|
error = LodePNG_inflate(&outv, in, insize, 2);
|
|
*out = outv.data;
|
|
*outsize = outv.size;
|
|
if(error) return error;
|
|
|
|
if(!settings->ignoreAdler32)
|
|
{
|
|
unsigned ADLER32 = LodePNG_read32bitInt(&in[insize - 4]);
|
|
unsigned checksum = adler32(outv.data, (unsigned)outv.size);
|
|
if(checksum != ADLER32) return 58; /*error, adler checksum not correct, data must be corrupted*/
|
|
}
|
|
|
|
return 0; /*no error*/
|
|
}
|
|
|
|
#endif /*LODEPNG_COMPILE_DECODER*/
|
|
|
|
#ifdef LODEPNG_COMPILE_ENCODER
|
|
|
|
unsigned LodePNG_zlib_compress(unsigned char** out, size_t* outsize, const unsigned char* in,
|
|
size_t insize, const LodePNG_CompressSettings* settings)
|
|
{
|
|
/*initially, *out must be NULL and outsize 0, if you just give some random *out
|
|
that's pointing to a non allocated buffer, this'll crash*/
|
|
ucvector deflatedata, outv;
|
|
size_t i;
|
|
unsigned error;
|
|
|
|
unsigned ADLER32;
|
|
/*zlib data: 1 byte CMF (CM+CINFO), 1 byte FLG, deflate data, 4 byte ADLER32 checksum of the Decompressed data*/
|
|
unsigned CMF = 120; /*0b01111000: CM 8, CINFO 7. With CINFO 7, any window size up to 32768 can be used.*/
|
|
unsigned FLEVEL = 0;
|
|
unsigned FDICT = 0;
|
|
unsigned CMFFLG = 256 * CMF + FDICT * 32 + FLEVEL * 64;
|
|
unsigned FCHECK = 31 - CMFFLG % 31;
|
|
CMFFLG += FCHECK;
|
|
|
|
/*ucvector-controlled version of the output buffer, for dynamic array*/
|
|
ucvector_init_buffer(&outv, *out, *outsize);
|
|
|
|
ucvector_push_back(&outv, (unsigned char)(CMFFLG / 256));
|
|
ucvector_push_back(&outv, (unsigned char)(CMFFLG % 256));
|
|
|
|
ucvector_init(&deflatedata);
|
|
error = LodePNG_deflate(&deflatedata, in, insize, settings);
|
|
|
|
if(!error)
|
|
{
|
|
ADLER32 = adler32(in, (unsigned)insize);
|
|
for(i = 0; i < deflatedata.size; i++) ucvector_push_back(&outv, deflatedata.data[i]);
|
|
ucvector_cleanup(&deflatedata);
|
|
LodePNG_add32bitInt(&outv, ADLER32);
|
|
}
|
|
|
|
*out = outv.data;
|
|
*outsize = outv.size;
|
|
|
|
return error;
|
|
}
|
|
|
|
#endif /*LODEPNG_COMPILE_ENCODER*/
|
|
|
|
#else /*no LODEPNG_COMPILE_ZLIB*/
|
|
|
|
/*
|
|
Dummy functions used if LODEPNG_COMPILE_ZLIB isn't defined. You need to implement
|
|
these yourself when disabling the LodePNG Zlib part, e.g. by calling another
|
|
library from here.
|
|
|
|
*out must be NULL and *outsize must be 0 initially, and after the function is done,
|
|
*out must point to the decompressed data, *outsize must be the size of it, and must
|
|
be the size of the useful data in bytes, not the alloc size.
|
|
*/
|
|
|
|
#ifdef LODEPNG_COMPILE_DECODER
|
|
static unsigned LodePNG_zlib_decompress(unsigned char** out, size_t* outsize, const unsigned char* in,
|
|
size_t insize, const LodePNG_DecompressSettings* settings)
|
|
{
|
|
return 0; //Placeholder to be implemented if LODEPNG_COMPILE_ZLIB is disabled.
|
|
}
|
|
#endif /*LODEPNG_COMPILE_DECODER*/
|
|
#ifdef LODEPNG_COMPILE_ENCODER
|
|
static unsigned LodePNG_zlib_compress(unsigned char** out, size_t* outsize, const unsigned char* in,
|
|
size_t insize, const LodePNG_CompressSettings* settings)
|
|
{
|
|
return 0; //Placeholder to be implemented if LODEPNG_COMPILE_ZLIB is disabled.
|
|
}
|
|
#endif /*LODEPNG_COMPILE_ENCODER*/
|
|
|
|
#endif /*LODEPNG_COMPILE_ZLIB*/
|
|
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
|
|
#ifdef LODEPNG_COMPILE_ENCODER
|
|
|
|
/*this is a good tradeoff between speed and compression ratio*/
|
|
#define DEFAULT_WINDOWSIZE 2048
|
|
|
|
void LodePNG_CompressSettings_init(LodePNG_CompressSettings* settings)
|
|
{
|
|
/*compress with dynamic huffman tree (not in the mathematical sense, just not the predefined one)*/
|
|
settings->btype = 2;
|
|
settings->useLZ77 = 1;
|
|
settings->windowSize = DEFAULT_WINDOWSIZE;
|
|
}
|
|
|
|
const LodePNG_CompressSettings LodePNG_defaultCompressSettings = {2, 1, DEFAULT_WINDOWSIZE};
|
|
|
|
#endif /*LODEPNG_COMPILE_ENCODER*/
|
|
|
|
#ifdef LODEPNG_COMPILE_DECODER
|
|
|
|
void LodePNG_DecompressSettings_init(LodePNG_DecompressSettings* settings)
|
|
{
|
|
settings->ignoreAdler32 = 0;
|
|
}
|
|
|
|
const LodePNG_DecompressSettings LodePNG_defaultDecompressSettings = {0};
|
|
|
|
#endif /*LODEPNG_COMPILE_DECODER*/
|
|
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
/* // End of Zlib related code. Begin of PNG related code. // */
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
|
|
#ifdef LODEPNG_COMPILE_PNG
|
|
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
/* / CRC32 / */
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
|
|
static unsigned Crc32_crc_table_computed = 0;
|
|
static unsigned Crc32_crc_table[256];
|
|
|
|
/*Make the table for a fast CRC.*/
|
|
static void Crc32_make_crc_table(void)
|
|
{
|
|
unsigned c, k, n;
|
|
for(n = 0; n < 256; n++)
|
|
{
|
|
c = n;
|
|
for(k = 0; k < 8; k++)
|
|
{
|
|
if(c & 1) c = 0xedb88320L ^ (c >> 1);
|
|
else c = c >> 1;
|
|
}
|
|
Crc32_crc_table[n] = c;
|
|
}
|
|
Crc32_crc_table_computed = 1;
|
|
}
|
|
|
|
/*Update a running CRC with the bytes buf[0..len-1]--the CRC should be
|
|
initialized to all 1's, and the transmitted value is the 1's complement of the
|
|
final running CRC (see the crc() routine below).*/
|
|
static unsigned Crc32_update_crc(const unsigned char* buf, unsigned crc, size_t len)
|
|
{
|
|
unsigned c = crc;
|
|
size_t n;
|
|
|
|
if(!Crc32_crc_table_computed) Crc32_make_crc_table();
|
|
for(n = 0; n < len; n++)
|
|
{
|
|
c = Crc32_crc_table[(c ^ buf[n]) & 0xff] ^ (c >> 8);
|
|
}
|
|
return c;
|
|
}
|
|
|
|
/*Return the CRC of the bytes buf[0..len-1].*/
|
|
static unsigned Crc32_crc(const unsigned char* buf, size_t len)
|
|
{
|
|
return Crc32_update_crc(buf, 0xffffffffL, len) ^ 0xffffffffL;
|
|
}
|
|
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
/* / Reading and writing single bits and bytes from/to stream for LodePNG / */
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
|
|
static unsigned char readBitFromReversedStream(size_t* bitpointer, const unsigned char* bitstream)
|
|
{
|
|
unsigned char result = (unsigned char)((bitstream[(*bitpointer) >> 3] >> (7 - ((*bitpointer) & 0x7))) & 1);
|
|
(*bitpointer)++;
|
|
return result;
|
|
}
|
|
|
|
static unsigned readBitsFromReversedStream(size_t* bitpointer, const unsigned char* bitstream, size_t nbits)
|
|
{
|
|
unsigned result = 0;
|
|
size_t i;
|
|
for(i = nbits - 1; i < nbits; i--)
|
|
{
|
|
result += (unsigned)readBitFromReversedStream(bitpointer, bitstream) << i;
|
|
}
|
|
return result;
|
|
}
|
|
|
|
#ifdef LODEPNG_COMPILE_DECODER
|
|
static void setBitOfReversedStream0(size_t* bitpointer, unsigned char* bitstream, unsigned char bit)
|
|
{
|
|
/*the current bit in bitstream must be 0 for this to work*/
|
|
if(bit)
|
|
{
|
|
/*earlier bit of huffman code is in a lesser significant bit of an earlier byte*/
|
|
bitstream[(*bitpointer) >> 3] |= (bit << (7 - ((*bitpointer) & 0x7)));
|
|
}
|
|
(*bitpointer)++;
|
|
}
|
|
#endif /*LODEPNG_COMPILE_DECODER*/
|
|
|
|
static void setBitOfReversedStream(size_t* bitpointer, unsigned char* bitstream, unsigned char bit)
|
|
{
|
|
/*the current bit in bitstream may be 0 or 1 for this to work*/
|
|
if(bit == 0) bitstream[(*bitpointer) >> 3] &= (unsigned char)(~(1 << (7 - ((*bitpointer) & 0x7))));
|
|
else bitstream[(*bitpointer) >> 3] |= (1 << (7 - ((*bitpointer) & 0x7)));
|
|
(*bitpointer)++;
|
|
}
|
|
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
/* / PNG chunks / */
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
|
|
unsigned LodePNG_chunk_length(const unsigned char* chunk)
|
|
{
|
|
return LodePNG_read32bitInt(&chunk[0]);
|
|
}
|
|
|
|
void LodePNG_chunk_type(char type[5], const unsigned char* chunk)
|
|
{
|
|
unsigned i;
|
|
for(i = 0; i < 4; i++) type[i] = chunk[4 + i];
|
|
type[4] = 0; /*null termination char*/
|
|
}
|
|
|
|
unsigned char LodePNG_chunk_type_equals(const unsigned char* chunk, const char* type)
|
|
{
|
|
if(strlen(type) != 4) return 0;
|
|
return (chunk[4] == type[0] && chunk[5] == type[1] && chunk[6] == type[2] && chunk[7] == type[3]);
|
|
}
|
|
|
|
unsigned char LodePNG_chunk_critical(const unsigned char* chunk)
|
|
{
|
|
return((chunk[4] & 32) == 0);
|
|
}
|
|
|
|
unsigned char LodePNG_chunk_private(const unsigned char* chunk)
|
|
{
|
|
return((chunk[6] & 32) != 0);
|
|
}
|
|
|
|
unsigned char LodePNG_chunk_safetocopy(const unsigned char* chunk)
|
|
{
|
|
return((chunk[7] & 32) != 0);
|
|
}
|
|
|
|
unsigned char* LodePNG_chunk_data(unsigned char* chunk)
|
|
{
|
|
return &chunk[8];
|
|
}
|
|
|
|
const unsigned char* LodePNG_chunk_data_const(const unsigned char* chunk)
|
|
{
|
|
return &chunk[8];
|
|
}
|
|
|
|
unsigned LodePNG_chunk_check_crc(const unsigned char* chunk)
|
|
{
|
|
unsigned length = LodePNG_chunk_length(chunk);
|
|
unsigned CRC = LodePNG_read32bitInt(&chunk[length + 8]);
|
|
/*the CRC is taken of the data and the 4 chunk type letters, not the length*/
|
|
unsigned checksum = Crc32_crc(&chunk[4], length + 4);
|
|
if(CRC != checksum) return 1;
|
|
else return 0;
|
|
}
|
|
|
|
void LodePNG_chunk_generate_crc(unsigned char* chunk)
|
|
{
|
|
unsigned length = LodePNG_chunk_length(chunk);
|
|
unsigned CRC = Crc32_crc(&chunk[4], length + 4);
|
|
LodePNG_set32bitInt(chunk + 8 + length, CRC);
|
|
}
|
|
|
|
unsigned char* LodePNG_chunk_next(unsigned char* chunk)
|
|
{
|
|
unsigned total_chunk_length = LodePNG_chunk_length(chunk) + 12;
|
|
return &chunk[total_chunk_length];
|
|
}
|
|
|
|
const unsigned char* LodePNG_chunk_next_const(const unsigned char* chunk)
|
|
{
|
|
unsigned total_chunk_length = LodePNG_chunk_length(chunk) + 12;
|
|
return &chunk[total_chunk_length];
|
|
}
|
|
|
|
unsigned LodePNG_append_chunk(unsigned char** out, size_t* outlength, const unsigned char* chunk)
|
|
{
|
|
unsigned i;
|
|
unsigned total_chunk_length = LodePNG_chunk_length(chunk) + 12;
|
|
unsigned char *chunk_start, *new_buffer;
|
|
size_t new_length = (*outlength) + total_chunk_length;
|
|
if(new_length < total_chunk_length || new_length < (*outlength)) return 77; /*integer overflow happened*/
|
|
|
|
new_buffer = (unsigned char*)realloc(*out, new_length);
|
|
if(!new_buffer) return 9929; /*alloc fail*/
|
|
(*out) = new_buffer;
|
|
(*outlength) = new_length;
|
|
chunk_start = &(*out)[new_length - total_chunk_length];
|
|
|
|
for(i = 0; i < total_chunk_length; i++) chunk_start[i] = chunk[i];
|
|
|
|
return 0;
|
|
}
|
|
|
|
unsigned LodePNG_create_chunk(unsigned char** out, size_t* outlength, unsigned length,
|
|
const char* type, const unsigned char* data)
|
|
{
|
|
unsigned i;
|
|
unsigned char *chunk, *new_buffer;
|
|
size_t new_length = (*outlength) + length + 12;
|
|
if(new_length < length + 12 || new_length < (*outlength)) return 77; /*integer overflow happened*/
|
|
new_buffer = (unsigned char*)realloc(*out, new_length);
|
|
if(!new_buffer) return 9930; /*alloc fail*/
|
|
(*out) = new_buffer;
|
|
(*outlength) = new_length;
|
|
chunk = &(*out)[(*outlength) - length - 12];
|
|
|
|
/*1: length*/
|
|
LodePNG_set32bitInt(chunk, (unsigned)length);
|
|
|
|
/*2: chunk name (4 letters)*/
|
|
chunk[4] = type[0];
|
|
chunk[5] = type[1];
|
|
chunk[6] = type[2];
|
|
chunk[7] = type[3];
|
|
|
|
/*3: the data*/
|
|
for(i = 0; i < length; i++) chunk[8 + i] = data[i];
|
|
|
|
/*4: CRC (of the chunkname characters and the data)*/
|
|
LodePNG_chunk_generate_crc(chunk);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
/* / Color types and such / */
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
|
|
/*return type is a LodePNG error code*/
|
|
static unsigned checkColorValidity(unsigned colorType, unsigned bd) /*bd = bitDepth*/
|
|
{
|
|
switch(colorType)
|
|
{
|
|
case 0: if(!(bd == 1 || bd == 2 || bd == 4 || bd == 8 || bd == 16)) return 37; break; /*grey*/
|
|
case 2: if(!( bd == 8 || bd == 16)) return 37; break; /*RGB*/
|
|
case 3: if(!(bd == 1 || bd == 2 || bd == 4 || bd == 8 )) return 37; break; /*palette*/
|
|
case 4: if(!( bd == 8 || bd == 16)) return 37; break; /*grey + alpha*/
|
|
case 6: if(!( bd == 8 || bd == 16)) return 37; break; /*RGBA*/
|
|
default: return 31;
|
|
}
|
|
return 0; /*allowed color type / bits combination*/
|
|
}
|
|
|
|
static unsigned getNumColorChannels(unsigned colorType)
|
|
{
|
|
switch(colorType)
|
|
{
|
|
case 0: return 1; /*grey*/
|
|
case 2: return 3; /*RGB*/
|
|
case 3: return 1; /*palette*/
|
|
case 4: return 2; /*grey + alpha*/
|
|
case 6: return 4; /*RGBA*/
|
|
}
|
|
return 0; /*unexisting color type*/
|
|
}
|
|
|
|
static unsigned getBpp(unsigned colorType, unsigned bitDepth)
|
|
{
|
|
/*bits per pixel is amount of channels * bits per channel*/
|
|
return getNumColorChannels(colorType) * bitDepth;
|
|
}
|
|
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
|
|
void LodePNG_InfoColor_init(LodePNG_InfoColor* info)
|
|
{
|
|
info->key_defined = 0;
|
|
info->key_r = info->key_g = info->key_b = 0;
|
|
info->colorType = 6;
|
|
info->bitDepth = 8;
|
|
info->palette = 0;
|
|
info->palettesize = 0;
|
|
}
|
|
|
|
void LodePNG_InfoColor_cleanup(LodePNG_InfoColor* info)
|
|
{
|
|
LodePNG_InfoColor_clearPalette(info);
|
|
}
|
|
|
|
void LodePNG_InfoColor_clearPalette(LodePNG_InfoColor* info)
|
|
{
|
|
if(info->palette) free(info->palette);
|
|
info->palettesize = 0;
|
|
}
|
|
|
|
unsigned LodePNG_InfoColor_addPalette(LodePNG_InfoColor* info,
|
|
unsigned char r, unsigned char g, unsigned char b, unsigned char a)
|
|
{
|
|
unsigned char* data;
|
|
/*the same resize technique as C++ std::vectors is used, and here it's made so that for a palette with
|
|
the max of 256 colors, it'll have the exact alloc size*/
|
|
if(!(info->palettesize & (info->palettesize - 1))) /*if palettesize is 0 or a power of two*/
|
|
{
|
|
/*allocated data must be at least 4* palettesize (for 4 color bytes)*/
|
|
size_t alloc_size = info->palettesize == 0 ? 4 : info->palettesize * 4 * 2;
|
|
data = (unsigned char*)realloc(info->palette, alloc_size);
|
|
if(!data) return 9931; /*alloc fail*/
|
|
else info->palette = data;
|
|
}
|
|
info->palette[4 * info->palettesize + 0] = r;
|
|
info->palette[4 * info->palettesize + 1] = g;
|
|
info->palette[4 * info->palettesize + 2] = b;
|
|
info->palette[4 * info->palettesize + 3] = a;
|
|
info->palettesize++;
|
|
return 0;
|
|
}
|
|
|
|
unsigned LodePNG_InfoColor_getBpp(const LodePNG_InfoColor* info)
|
|
{
|
|
/*calculate bits per pixel out of colorType and bitDepth*/
|
|
return getBpp(info->colorType, info->bitDepth);
|
|
}
|
|
|
|
unsigned LodePNG_InfoColor_getChannels(const LodePNG_InfoColor* info)
|
|
{
|
|
return getNumColorChannels(info->colorType);
|
|
}
|
|
|
|
unsigned LodePNG_InfoColor_isGreyscaleType(const LodePNG_InfoColor* info)
|
|
{
|
|
return info->colorType == 0 || info->colorType == 4;
|
|
}
|
|
|
|
unsigned LodePNG_InfoColor_isAlphaType(const LodePNG_InfoColor* info)
|
|
{
|
|
return (info->colorType & 4) != 0;
|
|
}
|
|
|
|
unsigned LodePNG_InfoColor_isPaletteType(const LodePNG_InfoColor* info)
|
|
{
|
|
return info->colorType == 3;
|
|
}
|
|
|
|
unsigned LodePNG_InfoColor_hasPaletteAlpha(const LodePNG_InfoColor* info)
|
|
{
|
|
size_t i;
|
|
for(i = 0; i < info->palettesize; i++)
|
|
{
|
|
if(info->palette[i * 4 + 3] < 255) return 1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
unsigned LodePNG_InfoColor_canHaveAlpha(const LodePNG_InfoColor* info)
|
|
{
|
|
return info->key_defined
|
|
|| LodePNG_InfoColor_isAlphaType(info)
|
|
|| LodePNG_InfoColor_hasPaletteAlpha(info);
|
|
}
|
|
|
|
unsigned LodePNG_InfoColor_equal(const LodePNG_InfoColor* info1, const LodePNG_InfoColor* info2)
|
|
{
|
|
return info1->colorType == info2->colorType
|
|
&& info1->bitDepth == info2->bitDepth; /*palette and color key not compared*/
|
|
}
|
|
|
|
#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS
|
|
void LodePNG_UnknownChunks_init(LodePNG_UnknownChunks* chunks)
|
|
{
|
|
unsigned i;
|
|
for(i = 0; i < 3; i++) chunks->data[i] = 0;
|
|
for(i = 0; i < 3; i++) chunks->datasize[i] = 0;
|
|
}
|
|
|
|
void LodePNG_UnknownChunks_cleanup(LodePNG_UnknownChunks* chunks)
|
|
{
|
|
unsigned i;
|
|
for(i = 0; i < 3; i++) free(chunks->data[i]);
|
|
}
|
|
|
|
unsigned LodePNG_UnknownChunks_copy(LodePNG_UnknownChunks* dest, const LodePNG_UnknownChunks* src)
|
|
{
|
|
unsigned i;
|
|
|
|
LodePNG_UnknownChunks_cleanup(dest);
|
|
|
|
for(i = 0; i < 3; i++)
|
|
{
|
|
size_t j;
|
|
dest->datasize[i] = src->datasize[i];
|
|
dest->data[i] = (unsigned char*)malloc(src->datasize[i]);
|
|
if(!dest->data[i] && dest->datasize[i]) return 9932; /*alloc fail*/
|
|
for(j = 0; j < src->datasize[i]; j++) dest->data[i][j] = src->data[i][j];
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/
|
|
|
|
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
|
|
void LodePNG_Text_init(LodePNG_Text* text)
|
|
{
|
|
text->num = 0;
|
|
text->keys = NULL;
|
|
text->strings = NULL;
|
|
}
|
|
|
|
void LodePNG_Text_cleanup(LodePNG_Text* text)
|
|
{
|
|
LodePNG_Text_clear(text);
|
|
}
|
|
|
|
unsigned LodePNG_Text_copy(LodePNG_Text* dest, const LodePNG_Text* source)
|
|
{
|
|
size_t i = 0;
|
|
dest->keys = 0;
|
|
dest->strings = 0;
|
|
dest->num = 0;
|
|
for(i = 0; i < source->num; i++)
|
|
{
|
|
unsigned error = LodePNG_Text_add(dest, source->keys[i], source->strings[i]);
|
|
if(error) return error;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
void LodePNG_Text_clear(LodePNG_Text* text)
|
|
{
|
|
size_t i;
|
|
for(i = 0; i < text->num; i++)
|
|
{
|
|
string_cleanup(&text->keys[i]);
|
|
string_cleanup(&text->strings[i]);
|
|
}
|
|
free(text->keys);
|
|
free(text->strings);
|
|
}
|
|
|
|
unsigned LodePNG_Text_add(LodePNG_Text* text, const char* key, const char* str)
|
|
{
|
|
char** new_keys = (char**)(realloc(text->keys, sizeof(char*) * (text->num + 1)));
|
|
char** new_strings = (char**)(realloc(text->strings, sizeof(char*) * (text->num + 1)));
|
|
if(!new_keys || !new_strings)
|
|
{
|
|
free(new_keys);
|
|
free(new_strings);
|
|
return 9933; /*alloc fail*/
|
|
}
|
|
|
|
text->num++;
|
|
text->keys = new_keys;
|
|
text->strings = new_strings;
|
|
|
|
string_init(&text->keys[text->num - 1]);
|
|
string_set(&text->keys[text->num - 1], key);
|
|
|
|
string_init(&text->strings[text->num - 1]);
|
|
string_set(&text->strings[text->num - 1], str);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/******************************************************************************/
|
|
|
|
void LodePNG_IText_init(LodePNG_IText* text)
|
|
{
|
|
text->num = 0;
|
|
text->keys = NULL;
|
|
text->langtags = NULL;
|
|
text->transkeys = NULL;
|
|
text->strings = NULL;
|
|
}
|
|
|
|
void LodePNG_IText_cleanup(LodePNG_IText* text)
|
|
{
|
|
LodePNG_IText_clear(text);
|
|
}
|
|
|
|
unsigned LodePNG_IText_copy(LodePNG_IText* dest, const LodePNG_IText* source)
|
|
{
|
|
size_t i = 0;
|
|
dest->keys = 0;
|
|
dest->langtags = 0;
|
|
dest->transkeys = 0;
|
|
dest->strings = 0;
|
|
dest->num = 0;
|
|
for(i = 0; i < source->num; i++)
|
|
{
|
|
unsigned error = LodePNG_IText_add(dest, source->keys[i], source->langtags[i],
|
|
source->transkeys[i], source->strings[i]);
|
|
if(error) return error;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
void LodePNG_IText_clear(LodePNG_IText* text)
|
|
{
|
|
size_t i;
|
|
for(i = 0; i < text->num; i++)
|
|
{
|
|
string_cleanup(&text->keys[i]);
|
|
string_cleanup(&text->langtags[i]);
|
|
string_cleanup(&text->transkeys[i]);
|
|
string_cleanup(&text->strings[i]);
|
|
}
|
|
free(text->keys);
|
|
free(text->langtags);
|
|
free(text->transkeys);
|
|
free(text->strings);
|
|
}
|
|
|
|
unsigned LodePNG_IText_add(LodePNG_IText* text, const char* key, const char* langtag,
|
|
const char* transkey, const char* str)
|
|
{
|
|
char** new_keys = (char**)(realloc(text->keys, sizeof(char*) * (text->num + 1)));
|
|
char** new_langtags = (char**)(realloc(text->langtags, sizeof(char*) * (text->num + 1)));
|
|
char** new_transkeys = (char**)(realloc(text->transkeys, sizeof(char*) * (text->num + 1)));
|
|
char** new_strings = (char**)(realloc(text->strings, sizeof(char*) * (text->num + 1)));
|
|
if(!new_keys || !new_langtags || !new_transkeys || !new_strings)
|
|
{
|
|
free(new_keys);
|
|
free(new_langtags);
|
|
free(new_transkeys);
|
|
free(new_strings);
|
|
return 9934; /*alloc fail*/
|
|
}
|
|
|
|
text->num++;
|
|
text->keys = new_keys;
|
|
text->langtags = new_langtags;
|
|
text->transkeys = new_transkeys;
|
|
text->strings = new_strings;
|
|
|
|
string_init(&text->keys[text->num - 1]);
|
|
string_set(&text->keys[text->num - 1], key);
|
|
|
|
string_init(&text->langtags[text->num - 1]);
|
|
string_set(&text->langtags[text->num - 1], langtag);
|
|
|
|
string_init(&text->transkeys[text->num - 1]);
|
|
string_set(&text->transkeys[text->num - 1], transkey);
|
|
|
|
string_init(&text->strings[text->num - 1]);
|
|
string_set(&text->strings[text->num - 1], str);
|
|
|
|
return 0;
|
|
}
|
|
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
|
|
|
|
void LodePNG_InfoPng_init(LodePNG_InfoPng* info)
|
|
{
|
|
info->width = info->height = 0;
|
|
LodePNG_InfoColor_init(&info->color);
|
|
info->interlaceMethod = 0;
|
|
info->compressionMethod = 0;
|
|
info->filterMethod = 0;
|
|
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
|
|
info->background_defined = 0;
|
|
info->background_r = info->background_g = info->background_b = 0;
|
|
|
|
LodePNG_Text_init(&info->text);
|
|
LodePNG_IText_init(&info->itext);
|
|
|
|
info->time_defined = 0;
|
|
info->phys_defined = 0;
|
|
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
|
|
#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS
|
|
LodePNG_UnknownChunks_init(&info->unknown_chunks);
|
|
#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/
|
|
}
|
|
|
|
void LodePNG_InfoPng_cleanup(LodePNG_InfoPng* info)
|
|
{
|
|
LodePNG_InfoColor_cleanup(&info->color);
|
|
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
|
|
LodePNG_Text_cleanup(&info->text);
|
|
LodePNG_IText_cleanup(&info->itext);
|
|
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
|
|
#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS
|
|
LodePNG_UnknownChunks_cleanup(&info->unknown_chunks);
|
|
#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/
|
|
}
|
|
|
|
unsigned LodePNG_InfoPng_copy(LodePNG_InfoPng* dest, const LodePNG_InfoPng* source)
|
|
{
|
|
unsigned error = 0;
|
|
LodePNG_InfoPng_cleanup(dest);
|
|
*dest = *source;
|
|
LodePNG_InfoColor_init(&dest->color);
|
|
error = LodePNG_InfoColor_copy(&dest->color, &source->color); if(error) return error;
|
|
|
|
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
|
|
error = LodePNG_Text_copy(&dest->text, &source->text); if(error) return error;
|
|
error = LodePNG_IText_copy(&dest->itext, &source->itext); if(error) return error;
|
|
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
|
|
|
|
#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS
|
|
LodePNG_UnknownChunks_init(&dest->unknown_chunks);
|
|
error = LodePNG_UnknownChunks_copy(&dest->unknown_chunks, &source->unknown_chunks); if(error) return error;
|
|
#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/
|
|
return error;
|
|
}
|
|
|
|
void LodePNG_InfoPng_swap(LodePNG_InfoPng* a, LodePNG_InfoPng* b)
|
|
{
|
|
LodePNG_InfoPng temp = *a;
|
|
*a = *b;
|
|
*b = temp;
|
|
}
|
|
|
|
unsigned LodePNG_InfoColor_copy(LodePNG_InfoColor* dest, const LodePNG_InfoColor* source)
|
|
{
|
|
size_t i;
|
|
LodePNG_InfoColor_cleanup(dest);
|
|
*dest = *source;
|
|
dest->palette = (unsigned char*)malloc(source->palettesize * 4);
|
|
if(!dest->palette && source->palettesize) return 9935; /*alloc fail*/
|
|
for(i = 0; i < source->palettesize * 4; i++) dest->palette[i] = source->palette[i];
|
|
return 0;
|
|
}
|
|
|
|
void LodePNG_InfoRaw_init(LodePNG_InfoRaw* info)
|
|
{
|
|
LodePNG_InfoColor_init(&info->color);
|
|
}
|
|
|
|
void LodePNG_InfoRaw_cleanup(LodePNG_InfoRaw* info)
|
|
{
|
|
LodePNG_InfoColor_cleanup(&info->color);
|
|
}
|
|
|
|
unsigned LodePNG_InfoRaw_copy(LodePNG_InfoRaw* dest, const LodePNG_InfoRaw* source)
|
|
{
|
|
unsigned error = 0;
|
|
LodePNG_InfoRaw_cleanup(dest);
|
|
*dest = *source;
|
|
LodePNG_InfoColor_init(&dest->color);
|
|
error = LodePNG_InfoColor_copy(&dest->color, &source->color);
|
|
return error; /*this variable could be removed, but it's more clear what is returned this way*/
|
|
}
|
|
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
|
|
/*convert from any color type to RGB or RGBA with 8 bits per sample*/
|
|
static unsigned LodePNG_convert_rgb_a_8(unsigned char* out, const unsigned char* in,
|
|
LodePNG_InfoColor* infoIn, size_t numpixels, unsigned bytes, unsigned alpha)
|
|
{
|
|
size_t i, c, bp = 0; /*bp = bitpointer, used by less-than-8-bit color types*/
|
|
|
|
if(infoIn->bitDepth == 8)
|
|
{
|
|
switch(infoIn->colorType)
|
|
{
|
|
case 0: /*greyscale color*/
|
|
for(i = 0; i < numpixels; i++)
|
|
{
|
|
out[bytes * i + 0] = out[bytes * i + 1] = out[bytes * i + 2] = in[i];
|
|
if(alpha) out[bytes * i + 3] = infoIn->key_defined && in[i] == infoIn->key_r ? 0 : 255;
|
|
}
|
|
break;
|
|
case 2: /*RGB color*/
|
|
for(i = 0; i < numpixels; i++)
|
|
{
|
|
for(c = 0; c < 3; c++) out[bytes * i + c] = in[3 * i + c];
|
|
if(alpha)
|
|
{
|
|
if(infoIn->key_defined == 1 && in[3 * i + 0] == infoIn->key_r
|
|
&& in[3 * i + 1] == infoIn->key_g && in[3 * i + 2] == infoIn->key_b)
|
|
out[bytes * i + 3] = 0;
|
|
else out[bytes * i + 3] = 255;
|
|
}
|
|
}
|
|
break;
|
|
case 3: /*indexed color (palette)*/
|
|
for(i = 0; i < numpixels; i++)
|
|
{
|
|
if(in[i] >= infoIn->palettesize) return 46; /*invalid palette index*/
|
|
for(c = 0; c < bytes; c++) out[bytes * i + c] = infoIn->palette[4 * in[i] + c];
|
|
}
|
|
break;
|
|
case 4: /*greyscale with alpha*/
|
|
for(i = 0; i < numpixels; i++)
|
|
{
|
|
out[bytes * i + 0] = out[bytes * i + 1] = out[bytes * i + 2] = in[2 * i + 0];
|
|
if(alpha) out[bytes * i + 3] = in[2 * i + 1];
|
|
}
|
|
break;
|
|
case 6: /*RGB with alpha*/
|
|
for(i = 0; i < numpixels; i++)
|
|
{
|
|
for(c = 0; c < bytes; c++) out[bytes * i + c] = in[4 * i + c];
|
|
}
|
|
break;
|
|
default: break;
|
|
}
|
|
}
|
|
else if(infoIn->bitDepth == 16)
|
|
{
|
|
switch(infoIn->colorType)
|
|
{
|
|
case 0: /*greyscale color*/
|
|
for(i = 0; i < numpixels; i++)
|
|
{
|
|
out[bytes * i + 0] = out[bytes * i + 1] = out[bytes * i + 2] = in[2 * i];
|
|
if(alpha) out[bytes * i + 3] = infoIn->key_defined && 256U * in[i] + in[i + 1] == infoIn->key_r ? 0 : 255;
|
|
}
|
|
break;
|
|
case 2: /*RGB color*/
|
|
for(i = 0; i < numpixels; i++)
|
|
{
|
|
if(alpha) out[bytes * i + 3] = 255;
|
|
for(c = 0; c < 3; c++) out[bytes * i + c] = in[6 * i + 2 * c];
|
|
if(alpha)
|
|
{
|
|
if(infoIn->key_defined && 256U * in[6 * i + 0] + in[6 * i + 1] == infoIn->key_r
|
|
&& 256U * in[6 * i + 2] + in[6 * i + 3] == infoIn->key_g
|
|
&& 256U * in[6 * i + 4] + in[6 * i + 5] == infoIn->key_b)
|
|
out[bytes * i + 3] = 0;
|
|
else out[bytes * i + 3] = 255;
|
|
}
|
|
}
|
|
break;
|
|
case 4: /*greyscale with alpha*/
|
|
for(i = 0; i < numpixels; i++)
|
|
{
|
|
out[bytes * i + 0] = out[bytes * i + 1] = out[bytes * i + 2] = in[4 * i];
|
|
if(alpha) out[bytes * i + 3] = in[4 * i + 2];
|
|
}
|
|
break;
|
|
case 6: /*RGB with alpha*/
|
|
for(i = 0; i < numpixels; i++)
|
|
{
|
|
for(c = 0; c < bytes; c++) out[bytes * i + c] = in[8 * i + 2 * c];
|
|
}
|
|
break;
|
|
default: break;
|
|
}
|
|
}
|
|
else /*infoIn->bitDepth is less than 8 bit per channel*/
|
|
{
|
|
switch(infoIn->colorType)
|
|
{
|
|
case 0: /*greyscale color*/
|
|
for(i = 0; i < numpixels; i++)
|
|
{
|
|
unsigned value = readBitsFromReversedStream(&bp, in, infoIn->bitDepth);
|
|
unsigned highest = ((1U << infoIn->bitDepth) - 1U); /*highest possible value for this bit depth*/
|
|
/*scale value from 0 to 255*/
|
|
out[bytes * i + 0] = out[bytes * i + 1] = out[bytes * i + 2]
|
|
= (unsigned char)((value * 255) / highest);
|
|
if(alpha) out[bytes * i + 3] = infoIn->key_defined && value == infoIn->key_r ? 0 : 255;
|
|
}
|
|
break;
|
|
case 3: /*indexed color (palette)*/
|
|
for(i = 0; i < numpixels; i++)
|
|
{
|
|
unsigned value = readBitsFromReversedStream(&bp, in, infoIn->bitDepth);
|
|
if(value >= infoIn->palettesize) return 47;
|
|
for(c = 0; c < bytes; c++) out[bytes * i + c] = infoIn->palette[4 * value + c];
|
|
}
|
|
break;
|
|
default: break;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/*convert from any greyscale color type to 8-bit greyscale with or without alpha channel*/
|
|
static unsigned LodePNG_convert_grey_8(unsigned char* out, const unsigned char* in,
|
|
LodePNG_InfoColor* infoIn, size_t numpixels, unsigned bytes, unsigned alpha)
|
|
{
|
|
size_t i, bp = 0; /*bp = bitpointer, used by less-than-8-bit color types*/
|
|
|
|
if(infoIn->bitDepth == 8)
|
|
{
|
|
switch(infoIn->colorType)
|
|
{
|
|
case 0: /*greyscale color*/
|
|
for(i = 0; i < numpixels; i++)
|
|
{
|
|
out[bytes * i] = in[i];
|
|
if(alpha) out[bytes * i + 1] = infoIn->key_defined && in[i] == infoIn->key_r ? 0 : 255;
|
|
}
|
|
break;
|
|
case 4: /*greyscale with alpha*/
|
|
for(i = 0; i < numpixels; i++)
|
|
{
|
|
out[bytes * i + 0] = in[2 * i + 0];
|
|
if(alpha) out[bytes * i + 1] = in[2 * i + 1];
|
|
}
|
|
break;
|
|
default: return 31;
|
|
}
|
|
}
|
|
else if(infoIn->bitDepth == 16)
|
|
{
|
|
switch(infoIn->colorType)
|
|
{
|
|
case 0: /*greyscale color*/
|
|
for(i = 0; i < numpixels; i++)
|
|
{
|
|
if(alpha) out[bytes * i + 1] = 255;
|
|
out[bytes * i] = in[2 * i];
|
|
if(alpha && infoIn->key_defined && 256U * in[i] + in[i + 1] == infoIn->key_r)
|
|
{
|
|
out[bytes * i + 1] = 0;
|
|
}
|
|
}
|
|
break;
|
|
case 4: /*greyscale with alpha*/
|
|
for(i = 0; i < numpixels; i++)
|
|
{
|
|
out[bytes * i] = in[4 * i]; /*most significant byte*/
|
|
if(alpha) out[bytes * i + 1] = in[4 * i + 2]; /*most significant byte*/
|
|
}
|
|
break;
|
|
default: return 31;
|
|
}
|
|
}
|
|
else /*infoIn->bitDepth is less than 8 bit per channel*/
|
|
{
|
|
if(infoIn->colorType != 0) return 31; /*colorType 0 is the only greyscale type with < 8 bits per channel*/
|
|
for(i = 0; i < numpixels; i++)
|
|
{
|
|
unsigned value = readBitsFromReversedStream(&bp, in, infoIn->bitDepth);
|
|
unsigned highest = ((1U << infoIn->bitDepth) - 1U); /*highest possible value for this bit depth*/
|
|
out[bytes * i] = (unsigned char)((value * 255) / highest); /*scale value from 0 to 255*/
|
|
if(alpha)
|
|
{
|
|
if(infoIn->key_defined && value == infoIn->key_r) out[bytes * i + 1] = 0;
|
|
else out[bytes * i + 1] = 255;
|
|
}
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/*convert from any color type to RGB or RGBA with 8 bits per sample*/
|
|
static unsigned LodePNG_convert_rgb_a_16(unsigned char* out, const unsigned char* in,
|
|
LodePNG_InfoColor* infoIn, size_t numpixels, unsigned bytes, unsigned alpha)
|
|
{
|
|
size_t i, c, bp = 0; /*bp = bitpointer, used by less-than-8-bit color types*/
|
|
|
|
if(infoIn->bitDepth == 8)
|
|
{
|
|
switch(infoIn->colorType)
|
|
{
|
|
case 0: /*greyscale color*/
|
|
for(i = 0; i < numpixels; i++)
|
|
{
|
|
out[bytes * i + 0] = out[bytes * i + 2] = out[bytes * i + 4] = in[i];
|
|
out[bytes * i + 1] = out[bytes * i + 3] = out[bytes * i + 5] = in[i];
|
|
if(alpha)
|
|
{
|
|
if(alpha && infoIn->key_defined && in[i] == infoIn->key_r) out[bytes * i + 6] = out[bytes * i + 7] = 0;
|
|
else out[bytes * i + 6] = out[bytes * i + 7] = 255;
|
|
}
|
|
}
|
|
break;
|
|
case 2: /*RGB color*/
|
|
for(i = 0; i < numpixels; i++)
|
|
{
|
|
out[bytes * i + 0] = out[bytes * i + 1] = in[3 * i + 0];
|
|
out[bytes * i + 2] = out[bytes * i + 3] = in[3 * i + 1];
|
|
out[bytes * i + 4] = out[bytes * i + 5] = in[3 * i + 2];
|
|
if(alpha)
|
|
{
|
|
if(infoIn->key_defined == 1 && in[3 * i + 0] == infoIn->key_r
|
|
&& in[3 * i + 1] == infoIn->key_g && in[3 * i + 2] == infoIn->key_b)
|
|
out[bytes * i + 6] = out[bytes * i + 7] = 0;
|
|
else out[bytes * i + 6] = out[bytes * i + 7] = 255;
|
|
}
|
|
}
|
|
break;
|
|
case 3: /*indexed color (palette)*/
|
|
for(i = 0; i < numpixels; i++)
|
|
{
|
|
if(in[i] >= infoIn->palettesize) return 46; /*invalid palette index*/
|
|
for(c = 0; c < bytes; c++)
|
|
{
|
|
out[bytes * i + 2 * c] = out[bytes * i + 2 * c + 1] = infoIn->palette[4 * in[i] + c];
|
|
}
|
|
}
|
|
break;
|
|
case 4: /*greyscale with alpha*/
|
|
for(i = 0; i < numpixels; i++)
|
|
{
|
|
out[bytes * i + 0] = out[bytes * i + 2] = out[bytes * i + 4] = in[i];
|
|
out[bytes * i + 1] = out[bytes * i + 3] = out[bytes * i + 5] = in[i];
|
|
if(alpha)
|
|
{
|
|
out[bytes * i + 6] = out[bytes * i + 7] = in[2 * i + 1];
|
|
}
|
|
}
|
|
break;
|
|
case 6: /*RGB with alpha*/
|
|
for(i = 0; i < numpixels; i++)
|
|
{
|
|
for(c = 0; c < 3; c++)
|
|
{
|
|
out[bytes * i + 2 * c] = out[bytes * i + 2 * c + 1] = in[4 * i + c];
|
|
}
|
|
if(alpha)
|
|
{
|
|
out[bytes * i + 6] = out[bytes * i + 7] = in[4 * i + c];
|
|
}
|
|
}
|
|
break;
|
|
default: break;
|
|
}
|
|
}
|
|
else if(infoIn->bitDepth == 16)
|
|
{
|
|
switch(infoIn->colorType)
|
|
{
|
|
case 0: /*greyscale color*/
|
|
for(i = 0; i < numpixels; i++)
|
|
{
|
|
out[bytes * i + 0] = out[bytes * i + 2] = out[bytes * i + 4] = in[2 * i];
|
|
out[bytes * i + 1] = out[bytes * i + 3] = out[bytes * i + 5] = in[2 * i + 1];
|
|
if(alpha)
|
|
{
|
|
if(infoIn->key_defined && 256U * in[i] + in[i + 1] == infoIn->key_r)
|
|
out[bytes * i + 6] = out[bytes * i + 7] = 0;
|
|
else out[bytes * i + 6] = out[bytes * i + 7] = 255;
|
|
}
|
|
}
|
|
break;
|
|
case 2: /*RGB color*/
|
|
for(i = 0; i < numpixels; i++)
|
|
{
|
|
for(c = 0; c < 6; c++) out[bytes * i + c] = in[6 * i + c];
|
|
if(alpha)
|
|
{
|
|
if(infoIn->key_defined && 256U * in[6 * i + 0] + in[6 * i + 1] == infoIn->key_r
|
|
&& 256U * in[6 * i + 2] + in[6 * i + 3] == infoIn->key_g
|
|
&& 256U * in[6 * i + 4] + in[6 * i + 5] == infoIn->key_b)
|
|
out[bytes * i + 6] = out[bytes * i + 7] = 0;
|
|
else out[bytes * i + 6] = out[bytes * i + 7] = 255;
|
|
}
|
|
}
|
|
break;
|
|
case 4: /*greyscale with alpha*/
|
|
for(i = 0; i < numpixels; i++)
|
|
{
|
|
out[bytes * i + 0] = out[bytes * i + 2] = out[bytes * i + 4] = in[4 * i + 0];
|
|
out[bytes * i + 1] = out[bytes * i + 3] = out[bytes * i + 5] = in[4 * i + 1];
|
|
if(alpha)
|
|
{
|
|
out[bytes * i + 6] = in[4 * i + 2];
|
|
out[bytes * i + 7] = in[4 * i + 3];
|
|
}
|
|
}
|
|
break;
|
|
case 6: /*RGB with alpha*/
|
|
for(i = 0; i < numpixels; i++)
|
|
{
|
|
for(c = 0; c < bytes; c++) out[bytes * i + c] = in[8 * i + 2 * c];
|
|
}
|
|
break;
|
|
default: break;
|
|
}
|
|
}
|
|
else /*infoIn->bitDepth is less than 8 bit per channel*/
|
|
{
|
|
switch(infoIn->colorType)
|
|
{
|
|
case 0: /*greyscale color*/
|
|
for(i = 0; i < numpixels; i++)
|
|
{
|
|
unsigned value = readBitsFromReversedStream(&bp, in, infoIn->bitDepth);
|
|
unsigned highest = ((1U << infoIn->bitDepth) - 1U); /*highest possible value for this bit depth*/
|
|
/*scale value from 0 to 255*/
|
|
out[bytes * i + 0] = out[bytes * i + 2] = out[bytes * i + 4]
|
|
= out[bytes * i + 1] = out[bytes * i + 3]
|
|
= out[bytes * i + 5] = (unsigned char)((value * 255) / highest);
|
|
if(alpha)
|
|
{
|
|
if(infoIn->key_defined && value == infoIn->key_r) out[bytes * i + 6] = out[bytes * i + 7] = 0;
|
|
else out[bytes * i + 6] = out[bytes * i + 7] = 255;
|
|
}
|
|
}
|
|
break;
|
|
case 3: /*indexed color (palette)*/
|
|
for(i = 0; i < numpixels; i++)
|
|
{
|
|
unsigned value = readBitsFromReversedStream(&bp, in, infoIn->bitDepth);
|
|
if(value >= infoIn->palettesize) return 47;
|
|
for(c = 0; c < bytes / 2; c++)
|
|
{
|
|
out[bytes * i + c * 2 + 0] = out[bytes * i + c * 2 + 1] = infoIn->palette[4 * value + c];
|
|
}
|
|
}
|
|
break;
|
|
default: break;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/*convert from any greyscale color type to 16-bit greyscale with or without alpha channel*/
|
|
static unsigned LodePNG_convert_grey_16(unsigned char* out, const unsigned char* in,
|
|
LodePNG_InfoColor* infoIn, size_t numpixels, unsigned bytes, unsigned alpha)
|
|
{
|
|
size_t i, c, bp = 0; /*bp = bitpointer, used by less-than-8-bit color types*/
|
|
|
|
if(infoIn->bitDepth == 8)
|
|
{
|
|
switch(infoIn->colorType)
|
|
{
|
|
case 0: /*greyscale color*/
|
|
for(i = 0; i < numpixels; i++)
|
|
{
|
|
out[bytes * i] = out[bytes * i + 1] = in[i];
|
|
if(alpha)
|
|
{
|
|
if(infoIn->key_defined && in[i] == infoIn->key_r) out[bytes * i + 2] = out[bytes * i + 3] = 0;
|
|
else out[bytes * i + 2] = out[bytes * i + 3] = 255;
|
|
}
|
|
}
|
|
break;
|
|
case 4: /*greyscale with alpha*/
|
|
for(i = 0; i < numpixels; i++)
|
|
{
|
|
out[bytes * i + 0] = out[bytes * i + 1] = in[2 * i + 0];
|
|
if(alpha) out[bytes * i + 2] = out[bytes * i + 3] = in[2 * i + 1];
|
|
}
|
|
break;
|
|
default: return 31;
|
|
}
|
|
}
|
|
else if(infoIn->bitDepth == 16)
|
|
{
|
|
switch(infoIn->colorType)
|
|
{
|
|
case 0: /*greyscale color*/
|
|
for(i = 0; i < numpixels; i++)
|
|
{
|
|
out[bytes * i + 0] = in[2 * i + 0];
|
|
out[bytes * i + 1] = in[2 * i + 1];
|
|
if(alpha)
|
|
{
|
|
if(infoIn->key_defined && 256U * in[i] + in[i + 1] == infoIn->key_r)
|
|
out[bytes * i + 2] = out[bytes * i + 3] = 0;
|
|
else out[bytes * i + 2] = out[bytes * i + 3] = 255;
|
|
}
|
|
}
|
|
break;
|
|
case 4: /*greyscale with alpha*/
|
|
for(i = 0; i < numpixels; i++)
|
|
{
|
|
for(c = 0; c < bytes; c++) out[bytes * i + c] = in[4 * i + c];
|
|
}
|
|
break;
|
|
default: return 31;
|
|
}
|
|
}
|
|
else /*infoIn->bitDepth is less than 8 bit per channel*/
|
|
{
|
|
if(infoIn->colorType != 0) return 31; /*colorType 0 is the only greyscale type with < 8 bits per channel*/
|
|
for(i = 0; i < numpixels; i++)
|
|
{
|
|
unsigned value = readBitsFromReversedStream(&bp, in, infoIn->bitDepth);
|
|
unsigned highest = ((1U << infoIn->bitDepth) - 1U); /*highest possible value for this bit depth*/
|
|
out[bytes * i] = out[bytes * i + 1] = (unsigned char)((value * 255) / highest); /*scale value from 0 to 255*/
|
|
if(alpha)
|
|
{
|
|
if(infoIn->key_defined && value == infoIn->key_r) out[bytes * i + 2] = out[bytes * i + 3] = 0;
|
|
else out[bytes * i + 2] = out[bytes * i + 3] = 255;
|
|
}
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
converts from any color type to 24-bit or 32-bit (later maybe more supported). return value = LodePNG error code
|
|
the out buffer must have (w * h * bpp + 7) / 8 bytes, where bpp is the bits per pixel of the output color type
|
|
(LodePNG_InfoColor_getBpp) for < 8 bpp images, there may _not_ be padding bits at the end of scanlines.
|
|
*/
|
|
unsigned LodePNG_convert(unsigned char* out, const unsigned char* in, LodePNG_InfoColor* infoOut,
|
|
LodePNG_InfoColor* infoIn, unsigned w, unsigned h)
|
|
{
|
|
size_t numpixels = w * h; /*amount of pixels*/
|
|
unsigned bytes = LodePNG_InfoColor_getBpp(infoOut) / 8; /*bytes per pixel in the output image*/
|
|
unsigned alpha = LodePNG_InfoColor_isAlphaType(infoOut); /*use 8-bit alpha channel*/
|
|
|
|
/*cases where in and out already have the same format*/
|
|
if(LodePNG_InfoColor_equal(infoIn, infoOut))
|
|
{
|
|
size_t i;
|
|
size_t size = (numpixels * LodePNG_InfoColor_getBpp(infoIn) + 7) / 8;
|
|
for(i = 0; i < size; i++) out[i] = in[i];
|
|
return 0;
|
|
}
|
|
else if((infoOut->colorType == 2 || infoOut->colorType == 6) && infoOut->bitDepth == 8)
|
|
{
|
|
LodePNG_convert_rgb_a_8(out, in, infoIn, numpixels, bytes, alpha);
|
|
}
|
|
else if(LodePNG_InfoColor_isGreyscaleType(infoOut) && infoOut->bitDepth == 8)
|
|
{
|
|
/*conversion from greyscale to greyscale*/
|
|
if(!LodePNG_InfoColor_isGreyscaleType(infoIn)) return 62; /*converting from color to grey is not supported*/
|
|
LodePNG_convert_grey_8(out, in, infoIn, numpixels, bytes, alpha);
|
|
}
|
|
else if((infoOut->colorType == 2 || infoOut->colorType == 6) && infoOut->bitDepth == 16)
|
|
{
|
|
LodePNG_convert_rgb_a_16(out, in, infoIn, numpixels, bytes, alpha);
|
|
}
|
|
else if(LodePNG_InfoColor_isGreyscaleType(infoOut) && infoOut->bitDepth == 16)
|
|
{
|
|
/*conversion from greyscale to greyscale*/
|
|
if(!LodePNG_InfoColor_isGreyscaleType(infoIn)) return 62; /*converting from color to grey is not supported*/
|
|
LodePNG_convert_grey_16(out, in, infoIn, numpixels, bytes, alpha);
|
|
}
|
|
else return 59; /*invalid color mode*/
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
Paeth predicter, used by PNG filter type 4
|
|
The parameters are of type short, but should come from unsigned chars, the shorts
|
|
are only needed to make the paeth calculation correct.
|
|
*/
|
|
static unsigned char paethPredictor(short a, short b, short c)
|
|
{
|
|
short pa = abs(b - c);
|
|
short pb = abs(a - c);
|
|
short pc = abs(a + b - c - c);
|
|
|
|
/*short pc = a + b - c;
|
|
short pa = abs(pc - a);
|
|
short pb = abs(pc - b);
|
|
pc = abs(pc - c);*/
|
|
|
|
if(pa <= pb && pa <= pc) return (unsigned char)a;
|
|
else if(pb <= pc) return (unsigned char)b;
|
|
else return (unsigned char)c;
|
|
}
|
|
|
|
/*shared values used by multiple Adam7 related functions*/
|
|
|
|
static const unsigned ADAM7_IX[7] = { 0, 4, 0, 2, 0, 1, 0 }; /*x start values*/
|
|
static const unsigned ADAM7_IY[7] = { 0, 0, 4, 0, 2, 0, 1 }; /*y start values*/
|
|
static const unsigned ADAM7_DX[7] = { 8, 8, 4, 4, 2, 2, 1 }; /*x delta values*/
|
|
static const unsigned ADAM7_DY[7] = { 8, 8, 8, 4, 4, 2, 2 }; /*y delta values*/
|
|
|
|
static void Adam7_getpassvalues(unsigned passw[7], unsigned passh[7], size_t filter_passstart[8],
|
|
size_t padded_passstart[8], size_t passstart[8], unsigned w, unsigned h, unsigned bpp)
|
|
{
|
|
/*the passstart values have 8 values: the 8th one indicates the byte after the end of the 7th (= last) pass*/
|
|
unsigned i;
|
|
|
|
/*calculate width and height in pixels of each pass*/
|
|
for(i = 0; i < 7; i++)
|
|
{
|
|
passw[i] = (w + ADAM7_DX[i] - ADAM7_IX[i] - 1) / ADAM7_DX[i];
|
|
passh[i] = (h + ADAM7_DY[i] - ADAM7_IY[i] - 1) / ADAM7_DY[i];
|
|
if(passw[i] == 0) passh[i] = 0;
|
|
if(passh[i] == 0) passw[i] = 0;
|
|
}
|
|
|
|
filter_passstart[0] = padded_passstart[0] = passstart[0] = 0;
|
|
for(i = 0; i < 7; i++)
|
|
{
|
|
/*if passw[i] is 0, it's 0 bytes, not 1 (no filtertype-byte)*/
|
|
filter_passstart[i + 1] = filter_passstart[i]
|
|
+ ((passw[i] && passh[i]) ? passh[i] * (1 + (passw[i] * bpp + 7) / 8) : 0);
|
|
/*bits padded if needed to fill full byte at end of each scanline*/
|
|
padded_passstart[i + 1] = padded_passstart[i] + passh[i] * ((passw[i] * bpp + 7) / 8);
|
|
/*only padded at end of reduced image*/
|
|
passstart[i + 1] = passstart[i] + (passh[i] * passw[i] * bpp + 7) / 8;
|
|
}
|
|
}
|
|
|
|
#ifdef LODEPNG_COMPILE_DECODER
|
|
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
/* / PNG Decoder / */
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
|
|
/*read the information from the header and store it in the LodePNG_Info. return value is error*/
|
|
void LodePNG_Decoder_inspect(LodePNG_Decoder* decoder, const unsigned char* in, size_t inlength)
|
|
{
|
|
if(inlength == 0 || in == 0)
|
|
{
|
|
decoder->error = 48; /*the given data is empty*/
|
|
return;
|
|
}
|
|
if(inlength < 29)
|
|
{
|
|
decoder->error = 27; /*error: the data length is smaller than the length of a PNG header*/
|
|
return;
|
|
}
|
|
|
|
/*when decoding a new PNG image, make sure all parameters created after previous decoding are reset*/
|
|
LodePNG_InfoPng_cleanup(&decoder->infoPng);
|
|
LodePNG_InfoPng_init(&decoder->infoPng);
|
|
decoder->error = 0;
|
|
|
|
if(in[0] != 137 || in[1] != 80 || in[2] != 78 || in[3] != 71
|
|
|| in[4] != 13 || in[5] != 10 || in[6] != 26 || in[7] != 10)
|
|
{
|
|
decoder->error = 28; /*error: the first 8 bytes are not the correct PNG signature*/
|
|
return;
|
|
}
|
|
if(in[12] != 'I' || in[13] != 'H' || in[14] != 'D' || in[15] != 'R')
|
|
{
|
|
decoder->error = 29; /*error: it doesn't start with a IHDR chunk!*/
|
|
return;
|
|
}
|
|
|
|
/*read the values given in the header*/
|
|
decoder->infoPng.width = LodePNG_read32bitInt(&in[16]);
|
|
decoder->infoPng.height = LodePNG_read32bitInt(&in[20]);
|
|
decoder->infoPng.color.bitDepth = in[24];
|
|
decoder->infoPng.color.colorType = in[25];
|
|
decoder->infoPng.compressionMethod = in[26];
|
|
decoder->infoPng.filterMethod = in[27];
|
|
decoder->infoPng.interlaceMethod = in[28];
|
|
|
|
if(!decoder->settings.ignoreCrc)
|
|
{
|
|
unsigned CRC = LodePNG_read32bitInt(&in[29]);
|
|
unsigned checksum = Crc32_crc(&in[12], 17);
|
|
if(CRC != checksum)
|
|
{
|
|
decoder->error = 57; /*invalid CRC*/
|
|
return;
|
|
}
|
|
}
|
|
|
|
/*error: only compression method 0 is allowed in the specification*/
|
|
if(decoder->infoPng.compressionMethod != 0) { decoder->error = 32; return; }
|
|
/*error: only filter method 0 is allowed in the specification*/
|
|
if(decoder->infoPng.filterMethod != 0) { decoder->error = 33; return; }
|
|
/*error: only interlace methods 0 and 1 exist in the specification*/
|
|
if(decoder->infoPng.interlaceMethod > 1) { decoder->error = 34; return; }
|
|
|
|
decoder->error = checkColorValidity(decoder->infoPng.color.colorType, decoder->infoPng.color.bitDepth);
|
|
}
|
|
|
|
static unsigned unfilterScanline(unsigned char* recon, const unsigned char* scanline, const unsigned char* precon,
|
|
size_t bytewidth, unsigned char filterType, size_t length)
|
|
{
|
|
/*
|
|
For PNG filter method 0
|
|
unfilter a PNG image scanline by scanline. when the pixels are smaller than 1 byte,
|
|
the filter works byte per byte (bytewidth = 1)
|
|
precon is the previous unfiltered scanline, recon the result, scanline the current one
|
|
the incoming scanlines do NOT include the filtertype byte, that one is given in the parameter filterType instead
|
|
recon and scanline MAY be the same memory address! precon must be disjoint.
|
|
*/
|
|
|
|
size_t i;
|
|
switch(filterType)
|
|
{
|
|
case 0:
|
|
for(i = 0; i < length; i++) recon[i] = scanline[i];
|
|
break;
|
|
case 1:
|
|
for(i = 0; i < bytewidth; i++) recon[i] = scanline[i];
|
|
for(i = bytewidth; i < length; i++) recon[i] = scanline[i] + recon[i - bytewidth];
|
|
break;
|
|
case 2:
|
|
if(precon)
|
|
{
|
|
for(i = 0; i < length; i++) recon[i] = scanline[i] + precon[i];
|
|
}
|
|
else
|
|
{
|
|
for(i = 0; i < length; i++) recon[i] = scanline[i];
|
|
}
|
|
break;
|
|
case 3:
|
|
if(precon)
|
|
{
|
|
for(i = 0; i < bytewidth; i++) recon[i] = scanline[i] + precon[i] / 2;
|
|
for(i = bytewidth; i < length; i++) recon[i] = scanline[i] + ((recon[i - bytewidth] + precon[i]) / 2);
|
|
}
|
|
else
|
|
{
|
|
for(i = 0; i < bytewidth; i++) recon[i] = scanline[i];
|
|
for(i = bytewidth; i < length; i++) recon[i] = scanline[i] + recon[i - bytewidth] / 2;
|
|
}
|
|
break;
|
|
case 4:
|
|
if(precon)
|
|
{
|
|
for(i = 0; i < bytewidth; i++)
|
|
{
|
|
recon[i] = (scanline[i] + precon[i]); /*paethPredictor(0, precon[i], 0) is always precon[i]*/
|
|
}
|
|
for(i = bytewidth; i < length; i++)
|
|
{
|
|
recon[i] = (scanline[i] + paethPredictor(recon[i - bytewidth], precon[i], precon[i - bytewidth]));
|
|
}
|
|
}
|
|
else
|
|
{
|
|
for(i = 0; i < bytewidth; i++)
|
|
{
|
|
recon[i] = scanline[i];
|
|
}
|
|
for(i = bytewidth; i < length; i++)
|
|
{
|
|
/*paethPredictor(recon[i - bytewidth], 0, 0) is always recon[i - bytewidth]*/
|
|
recon[i] = (scanline[i] + recon[i - bytewidth]);
|
|
}
|
|
}
|
|
break;
|
|
default: return 36; /*error: unexisting filter type given*/
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static unsigned unfilter(unsigned char* out, const unsigned char* in, unsigned w, unsigned h, unsigned bpp)
|
|
{
|
|
/*
|
|
For PNG filter method 0
|
|
this function unfilters a single image (e.g. without interlacing this is called once, with Adam7 seven times)
|
|
out must have enough bytes allocated already, in must have the scanlines + 1 filtertype byte per scanline
|
|
w and h are image dimensions or dimensions of reduced image, bpp is bits per pixel
|
|
in and out are allowed to be the same memory address (but aren't the same size since in has the extra filter bytes)
|
|
*/
|
|
|
|
unsigned y;
|
|
unsigned char* prevline = 0;
|
|
|
|
/*bytewidth is used for filtering, is 1 when bpp < 8, number of bytes per pixel otherwise*/
|
|
size_t bytewidth = (bpp + 7) / 8;
|
|
size_t linebytes = (w * bpp + 7) / 8;
|
|
|
|
for(y = 0; y < h; y++)
|
|
{
|
|
size_t outindex = linebytes * y;
|
|
size_t inindex = (1 + linebytes) * y; /*the extra filterbyte added to each row*/
|
|
unsigned char filterType = in[inindex];
|
|
|
|
unsigned error = unfilterScanline(&out[outindex], &in[inindex + 1], prevline, bytewidth, filterType, linebytes);
|
|
if(error) return error;
|
|
|
|
prevline = &out[outindex];
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void Adam7_deinterlace(unsigned char* out, const unsigned char* in, unsigned w, unsigned h, unsigned bpp)
|
|
{
|
|
/*Note: this function works on image buffers WITHOUT padding bits at end of scanlines
|
|
with non-multiple-of-8 bit amounts, only between reduced images is padding
|
|
out must be big enough AND must be 0 everywhere if bpp < 8 in the current implementation
|
|
(because that's likely a little bit faster)*/
|
|
unsigned passw[7], passh[7];
|
|
size_t filter_passstart[8], padded_passstart[8], passstart[8];
|
|
unsigned i;
|
|
|
|
Adam7_getpassvalues(passw, passh, filter_passstart, padded_passstart, passstart, w, h, bpp);
|
|
|
|
if(bpp >= 8)
|
|
{
|
|
for(i = 0; i < 7; i++)
|
|
{
|
|
unsigned x, y, b;
|
|
size_t bytewidth = bpp / 8;
|
|
for(y = 0; y < passh[i]; y++)
|
|
for(x = 0; x < passw[i]; x++)
|
|
{
|
|
size_t pixelinstart = passstart[i] + (y * passw[i] + x) * bytewidth;
|
|
size_t pixeloutstart = ((ADAM7_IY[i] + y * ADAM7_DY[i]) * w + ADAM7_IX[i] + x * ADAM7_DX[i]) * bytewidth;
|
|
for(b = 0; b < bytewidth; b++)
|
|
{
|
|
out[pixeloutstart + b] = in[pixelinstart + b];
|
|
}
|
|
}
|
|
}
|
|
}
|
|
else /*bpp < 8: Adam7 with pixels < 8 bit is a bit trickier: with bit pointers*/
|
|
{
|
|
for(i = 0; i < 7; i++)
|
|
{
|
|
unsigned x, y, b;
|
|
unsigned ilinebits = bpp * passw[i];
|
|
unsigned olinebits = bpp * w;
|
|
size_t obp, ibp; /*bit pointers (for out and in buffer)*/
|
|
for(y = 0; y < passh[i]; y++)
|
|
for(x = 0; x < passw[i]; x++)
|
|
{
|
|
ibp = (8 * passstart[i]) + (y * ilinebits + x * bpp);
|
|
obp = (ADAM7_IY[i] + y * ADAM7_DY[i]) * olinebits + (ADAM7_IX[i] + x * ADAM7_DX[i]) * bpp;
|
|
for(b = 0; b < bpp; b++)
|
|
{
|
|
unsigned char bit = readBitFromReversedStream(&ibp, in);
|
|
/*note that this function assumes the out buffer is completely 0, use setBitOfReversedStream otherwise*/
|
|
setBitOfReversedStream0(&obp, out, bit);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
static void removePaddingBits(unsigned char* out, const unsigned char* in,
|
|
size_t olinebits, size_t ilinebits, unsigned h)
|
|
{
|
|
/*
|
|
After filtering there are still padding bits if scanlines have non multiple of 8 bit amounts. They need
|
|
to be removed (except at last scanline of (Adam7-reduced) image) before working with pure image buffers
|
|
for the Adam7 code, the color convert code and the output to the user.
|
|
in and out are allowed to be the same buffer, in may also be higher but still overlapping; in must
|
|
have >= ilinebits*h bits, out must have >= olinebits*h bits, olinebits must be <= ilinebits
|
|
also used to move bits after earlier such operations happened, e.g. in a sequence of reduced images from Adam7
|
|
only useful if (ilinebits - olinebits) is a value in the range 1..7
|
|
*/
|
|
unsigned y;
|
|
size_t diff = ilinebits - olinebits;
|
|
size_t ibp = 0, obp = 0; /*input and output bit pointers*/
|
|
for(y = 0; y < h; y++)
|
|
{
|
|
size_t x;
|
|
for(x = 0; x < olinebits; x++)
|
|
{
|
|
unsigned char bit = readBitFromReversedStream(&ibp, in);
|
|
setBitOfReversedStream(&obp, out, bit);
|
|
}
|
|
ibp += diff;
|
|
}
|
|
}
|
|
|
|
/*out must be buffer big enough to contain full image, and in must contain the full decompressed data from
|
|
the IDAT chunks (with filter index bytes and possible padding bits)
|
|
return value is error*/
|
|
static unsigned postProcessScanlines(unsigned char* out, unsigned char* in, const LodePNG_InfoPng* infoPng)
|
|
{
|
|
/*
|
|
This function converts the filtered-padded-interlaced data into pure 2D image buffer with the PNG's colortype.
|
|
Steps:
|
|
*) if no Adam7: 1) unfilter 2) remove padding bits (= posible extra bits per scanline if bpp < 8)
|
|
*) if adam7: 1) 7x unfilter 2) 7x remove padding bits 3) Adam7_deinterlace
|
|
NOTE: the in buffer will be overwritten with intermediate data!
|
|
*/
|
|
unsigned bpp = LodePNG_InfoColor_getBpp(&infoPng->color);
|
|
unsigned w = infoPng->width;
|
|
unsigned h = infoPng->height;
|
|
unsigned error = 0;
|
|
if(bpp == 0) return 31; /*error: invalid colortype*/
|
|
|
|
if(infoPng->interlaceMethod == 0)
|
|
{
|
|
if(bpp < 8 && w * bpp != ((w * bpp + 7) / 8) * 8)
|
|
{
|
|
error = unfilter(in, in, w, h, bpp);
|
|
if(error) return error;
|
|
removePaddingBits(out, in, w * bpp, ((w * bpp + 7) / 8) * 8, h);
|
|
}
|
|
else error = unfilter(out, in, w, h, bpp); /*we can immediatly filter into the out buffer, no other steps needed*/
|
|
}
|
|
else /*interlaceMethod is 1 (Adam7)*/
|
|
{
|
|
unsigned passw[7], passh[7]; size_t filter_passstart[8], padded_passstart[8], passstart[8];
|
|
unsigned i;
|
|
|
|
Adam7_getpassvalues(passw, passh, filter_passstart, padded_passstart, passstart, w, h, bpp);
|
|
|
|
for(i = 0; i < 7; i++)
|
|
{
|
|
error = unfilter(&in[padded_passstart[i]], &in[filter_passstart[i]], passw[i], passh[i], bpp);
|
|
if(error) return error;
|
|
/*TODO: possible efficiency improvement: if in this reduced image the bits fit nicely in 1 scanline,
|
|
move bytes instead of bits or move not at all*/
|
|
if(bpp < 8)
|
|
{
|
|
/*remove padding bits in scanlines; after this there still may be padding
|
|
bits between the different reduced images: each reduced image still starts nicely at a byte*/
|
|
removePaddingBits(&in[passstart[i]], &in[padded_passstart[i]], passw[i] * bpp,
|
|
((passw[i] * bpp + 7) / 8) * 8, passh[i]);
|
|
}
|
|
}
|
|
|
|
Adam7_deinterlace(out, in, w, h, bpp);
|
|
}
|
|
|
|
return error;
|
|
}
|
|
|
|
/*read a PNG, the result will be in the same color type as the PNG (hence "generic")*/
|
|
static void decodeGeneric(LodePNG_Decoder* decoder, unsigned char** out, size_t* outsize,
|
|
const unsigned char* in, size_t insize)
|
|
{
|
|
unsigned char IEND = 0;
|
|
const unsigned char* chunk;
|
|
size_t i;
|
|
ucvector idat; /*the data from idat chunks*/
|
|
|
|
/*for unknown chunk order*/
|
|
unsigned unknown = 0;
|
|
#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS
|
|
unsigned critical_pos = 1; /*1 = after IHDR, 2 = after PLTE, 3 = after IDAT*/
|
|
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
|
|
|
|
/*provide some proper output values if error will happen*/
|
|
*out = 0;
|
|
*outsize = 0;
|
|
|
|
LodePNG_Decoder_inspect(decoder, in, insize); /*reads header and resets other parameters in decoder->infoPng*/
|
|
if(decoder->error) return;
|
|
|
|
ucvector_init(&idat);
|
|
|
|
chunk = &in[33]; /*first byte of the first chunk after the header*/
|
|
|
|
/*loop through the chunks, ignoring unknown chunks and stopping at IEND chunk.
|
|
IDAT data is put at the start of the in buffer*/
|
|
while(!IEND)
|
|
{
|
|
unsigned chunkLength;
|
|
const unsigned char* data; /*the data in the chunk*/
|
|
|
|
/*error: size of the in buffer too small to contain next chunk*/
|
|
if((size_t)((chunk - in) + 12) > insize || chunk < in) CERROR_BREAK(decoder->error, 30);
|
|
|
|
/*length of the data of the chunk, excluding the length bytes, chunk type and CRC bytes*/
|
|
chunkLength = LodePNG_chunk_length(chunk);
|
|
/*error: chunk length larger than the max PNG chunk size*/
|
|
if(chunkLength > 2147483647) CERROR_BREAK(decoder->error, 63);
|
|
|
|
if((size_t)((chunk - in) + chunkLength + 12) > insize || (chunk + chunkLength + 12) < in)
|
|
{
|
|
CERROR_BREAK(decoder->error, 64); /*error: size of the in buffer too small to contain next chunk*/
|
|
}
|
|
|
|
data = LodePNG_chunk_data_const(chunk);
|
|
|
|
/*IDAT chunk, containing compressed image data*/
|
|
if(LodePNG_chunk_type_equals(chunk, "IDAT"))
|
|
{
|
|
size_t oldsize = idat.size;
|
|
if(!ucvector_resize(&idat, oldsize + chunkLength)) CERROR_BREAK(decoder->error, 9936 /*alloc fail*/);
|
|
for(i = 0; i < chunkLength; i++) idat.data[oldsize + i] = data[i];
|
|
#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS
|
|
critical_pos = 3;
|
|
#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/
|
|
}
|
|
/*IEND chunk*/
|
|
else if(LodePNG_chunk_type_equals(chunk, "IEND"))
|
|
{
|
|
IEND = 1;
|
|
}
|
|
/*palette chunk (PLTE)*/
|
|
else if(LodePNG_chunk_type_equals(chunk, "PLTE"))
|
|
{
|
|
unsigned pos = 0;
|
|
if(decoder->infoPng.color.palette) free(decoder->infoPng.color.palette);
|
|
decoder->infoPng.color.palettesize = chunkLength / 3;
|
|
decoder->infoPng.color.palette = (unsigned char*)malloc(4 * decoder->infoPng.color.palettesize);
|
|
if(!decoder->infoPng.color.palette && decoder->infoPng.color.palettesize)
|
|
{
|
|
decoder->infoPng.color.palettesize = 0;
|
|
CERROR_BREAK(decoder->error, 9937); /*alloc fail*/
|
|
}
|
|
if(decoder->infoPng.color.palettesize > 256) CERROR_BREAK(decoder->error, 38); /*error: palette too big*/
|
|
|
|
for(i = 0; i < decoder->infoPng.color.palettesize; i++)
|
|
{
|
|
decoder->infoPng.color.palette[4 * i + 0] = data[pos++]; /*R*/
|
|
decoder->infoPng.color.palette[4 * i + 1] = data[pos++]; /*G*/
|
|
decoder->infoPng.color.palette[4 * i + 2] = data[pos++]; /*B*/
|
|
decoder->infoPng.color.palette[4 * i + 3] = 255; /*alpha*/
|
|
}
|
|
#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS
|
|
critical_pos = 2;
|
|
#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/
|
|
}
|
|
/*palette transparency chunk (tRNS)*/
|
|
else if(LodePNG_chunk_type_equals(chunk, "tRNS"))
|
|
{
|
|
if(decoder->infoPng.color.colorType == 3)
|
|
{
|
|
/*error: more alpha values given than there are palette entries*/
|
|
if(chunkLength > decoder->infoPng.color.palettesize) CERROR_BREAK(decoder->error, 38);
|
|
|
|
for(i = 0; i < chunkLength; i++) decoder->infoPng.color.palette[4 * i + 3] = data[i];
|
|
}
|
|
else if(decoder->infoPng.color.colorType == 0)
|
|
{
|
|
/*error: this chunk must be 2 bytes for greyscale image*/
|
|
if(chunkLength != 2) CERROR_BREAK(decoder->error, 30);
|
|
|
|
decoder->infoPng.color.key_defined = 1;
|
|
decoder->infoPng.color.key_r = decoder->infoPng.color.key_g
|
|
= decoder->infoPng.color.key_b = 256 * data[0] + data[1];
|
|
}
|
|
else if(decoder->infoPng.color.colorType == 2)
|
|
{
|
|
/*error: this chunk must be 6 bytes for RGB image*/
|
|
if(chunkLength != 6) CERROR_BREAK(decoder->error, 41);
|
|
|
|
decoder->infoPng.color.key_defined = 1;
|
|
decoder->infoPng.color.key_r = 256 * data[0] + data[1];
|
|
decoder->infoPng.color.key_g = 256 * data[2] + data[3];
|
|
decoder->infoPng.color.key_b = 256 * data[4] + data[5];
|
|
}
|
|
else CERROR_BREAK(decoder->error, 42); /*error: tRNS chunk not allowed for other color models*/
|
|
}
|
|
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
|
|
/*background color chunk (bKGD)*/
|
|
else if(LodePNG_chunk_type_equals(chunk, "bKGD"))
|
|
{
|
|
if(decoder->infoPng.color.colorType == 3)
|
|
{
|
|
/*error: this chunk must be 1 byte for indexed color image*/
|
|
if(chunkLength != 1) CERROR_BREAK(decoder->error, 43);
|
|
|
|
decoder->infoPng.background_defined = 1;
|
|
decoder->infoPng.background_r = decoder->infoPng.background_g = decoder->infoPng.background_b = data[0];
|
|
}
|
|
else if(decoder->infoPng.color.colorType == 0 || decoder->infoPng.color.colorType == 4)
|
|
{
|
|
/*error: this chunk must be 2 bytes for greyscale image*/
|
|
if(chunkLength != 2) CERROR_BREAK(decoder->error, 44);
|
|
|
|
decoder->infoPng.background_defined = 1;
|
|
decoder->infoPng.background_r = decoder->infoPng.background_g = decoder->infoPng.background_b
|
|
= 256 * data[0] + data[1];
|
|
}
|
|
else if(decoder->infoPng.color.colorType == 2 || decoder->infoPng.color.colorType == 6)
|
|
{
|
|
/*error: this chunk must be 6 bytes for greyscale image*/
|
|
if(chunkLength != 6) CERROR_BREAK(decoder->error, 45);
|
|
|
|
decoder->infoPng.background_defined = 1;
|
|
decoder->infoPng.background_r = 256 * data[0] + data[1];
|
|
decoder->infoPng.background_g = 256 * data[2] + data[3];
|
|
decoder->infoPng.background_b = 256 * data[4] + data[5];
|
|
}
|
|
}
|
|
/*text chunk (tEXt)*/
|
|
else if(LodePNG_chunk_type_equals(chunk, "tEXt"))
|
|
{
|
|
if(decoder->settings.readTextChunks)
|
|
{
|
|
char *key = 0, *str = 0;
|
|
|
|
while(!decoder->error) /*not really a while loop, only used to break on error*/
|
|
{
|
|
unsigned length, string2_begin;
|
|
|
|
length = 0;
|
|
while(length < chunkLength && data[length] != 0) length++;
|
|
/*error, end reached, no null terminator?*/
|
|
if(length + 1 >= chunkLength) CERROR_BREAK(decoder->error, 75);
|
|
|
|
key = (char*)malloc(length + 1);
|
|
if(!key) CERROR_BREAK(decoder->error, 9938); /*alloc fail*/
|
|
|
|
key[length] = 0;
|
|
for(i = 0; i < length; i++) key[i] = data[i];
|
|
|
|
string2_begin = length + 1;
|
|
/*error, end reached, no null terminator?*/
|
|
if(string2_begin > chunkLength) CERROR_BREAK(decoder->error, 75);
|
|
|
|
length = chunkLength - string2_begin;
|
|
str = (char*)malloc(length + 1);
|
|
if(!str) CERROR_BREAK(decoder->error, 9939); /*alloc fail*/
|
|
|
|
str[length] = 0;
|
|
for(i = 0; i < length; i++) str[i] = data[string2_begin + i];
|
|
|
|
decoder->error = LodePNG_Text_add(&decoder->infoPng.text, key, str);
|
|
|
|
break;
|
|
}
|
|
|
|
free(key);
|
|
free(str);
|
|
}
|
|
}
|
|
/*compressed text chunk (zTXt)*/
|
|
else if(LodePNG_chunk_type_equals(chunk, "zTXt"))
|
|
{
|
|
if(decoder->settings.readTextChunks)
|
|
{
|
|
unsigned length, string2_begin;
|
|
char *key = 0;
|
|
ucvector decoded;
|
|
|
|
ucvector_init(&decoded);
|
|
|
|
while(!decoder->error) /*not really a while loop, only used to break on error*/
|
|
{
|
|
for(length = 0; length < chunkLength && data[length] != 0; length++) ;
|
|
if(length + 2 >= chunkLength) CERROR_BREAK(decoder->error, 75); /*no null termination, corrupt?*/
|
|
|
|
key = (char*)malloc(length + 1);
|
|
if(!key) CERROR_BREAK(decoder->error, 9940); /*alloc fail*/
|
|
|
|
key[length] = 0;
|
|
for(i = 0; i < length; i++) key[i] = data[i];
|
|
|
|
if(data[length + 1] != 0) CERROR_BREAK(decoder->error, 72); /*the 0 byte indicating compression must be 0*/
|
|
|
|
string2_begin = length + 2;
|
|
if(string2_begin > chunkLength) CERROR_BREAK(decoder->error, 75); /*no null termination, corrupt?*/
|
|
|
|
length = chunkLength - string2_begin;
|
|
decoder->error = LodePNG_zlib_decompress(&decoded.data, &decoded.size,
|
|
(unsigned char*)(&data[string2_begin]),
|
|
length, &decoder->settings.zlibsettings);
|
|
if(decoder->error) break;
|
|
ucvector_push_back(&decoded, 0);
|
|
|
|
decoder->error = LodePNG_Text_add(&decoder->infoPng.text, key, (char*)decoded.data);
|
|
|
|
break;
|
|
}
|
|
|
|
free(key);
|
|
ucvector_cleanup(&decoded);
|
|
if(decoder->error) break;
|
|
}
|
|
}
|
|
/*international text chunk (iTXt)*/
|
|
else if(LodePNG_chunk_type_equals(chunk, "iTXt"))
|
|
{
|
|
if(decoder->settings.readTextChunks)
|
|
{
|
|
unsigned length, begin, compressed;
|
|
char *key = 0, *langtag = 0, *transkey = 0;
|
|
ucvector decoded;
|
|
ucvector_init(&decoded);
|
|
|
|
while(!decoder->error) /*not really a while loop, only used to break on error*/
|
|
{
|
|
/*Quick check if the chunk length isn't too small. Even without check
|
|
it'd still fail with other error checks below if it's too short. This just gives a different error code.*/
|
|
if(chunkLength < 5) CERROR_BREAK(decoder->error, 30); /*iTXt chunk too short*/
|
|
|
|
/*read the key*/
|
|
for(length = 0; length < chunkLength && data[length] != 0; length++) ;
|
|
if(length + 2 >= chunkLength) CERROR_BREAK(decoder->error, 75); /*no null termination char found*/
|
|
|
|
key = (char*)malloc(length + 1);
|
|
if(!key) CERROR_BREAK(decoder->error, 9941); /*alloc fail*/
|
|
|
|
key[length] = 0;
|
|
for(i = 0; i < length; i++) key[i] = data[i];
|
|
|
|
/*read the compression method*/
|
|
compressed = data[length + 1];
|
|
if(data[length + 2] != 0) CERROR_BREAK(decoder->error, 72); /*the 0 byte indicating compression must be 0*/
|
|
|
|
/*read the langtag*/
|
|
begin = length + 3;
|
|
length = 0;
|
|
for(i = begin; i < chunkLength && data[i] != 0; i++) length++;
|
|
if(begin + length + 1 >= chunkLength) CERROR_BREAK(decoder->error, 75); /*no null termination char found*/
|
|
|
|
langtag = (char*)malloc(length + 1);
|
|
if(!langtag) CERROR_BREAK(decoder->error, 9942); /*alloc fail*/
|
|
|
|
langtag[length] = 0;
|
|
for(i = 0; i < length; i++) langtag[i] = data[begin + i];
|
|
|
|
/*read the transkey*/
|
|
begin += length + 1;
|
|
length = 0;
|
|
for(i = begin; i < chunkLength && data[i] != 0; i++) length++;
|
|
if(begin + length + 1 >= chunkLength) CERROR_BREAK(decoder->error, 75); /*no null termination, corrupt?*/
|
|
|
|
transkey = (char*)malloc(length + 1);
|
|
if(!transkey) CERROR_BREAK(decoder->error, 9943); /*alloc fail*/
|
|
|
|
transkey[length] = 0;
|
|
for(i = 0; i < length; i++) transkey[i] = data[begin + i];
|
|
|
|
/*read the actual text*/
|
|
begin += length + 1;
|
|
if(begin > chunkLength) CERROR_BREAK(decoder->error, 75); /*no null termination, corrupt?*/
|
|
|
|
length = chunkLength - begin;
|
|
|
|
if(compressed)
|
|
{
|
|
decoder->error = LodePNG_zlib_decompress(&decoded.data, &decoded.size,
|
|
(unsigned char*)(&data[begin]),
|
|
length, &decoder->settings.zlibsettings);
|
|
if(decoder->error) break;
|
|
ucvector_push_back(&decoded, 0);
|
|
}
|
|
else
|
|
{
|
|
if(!ucvector_resize(&decoded, length + 1)) CERROR_BREAK(decoder->error, 9944 /*alloc fail*/);
|
|
|
|
decoded.data[length] = 0;
|
|
for(i = 0; i < length; i++) decoded.data[i] = data[begin + i];
|
|
}
|
|
|
|
decoder->error = LodePNG_IText_add(&decoder->infoPng.itext, key, langtag, transkey, (char*)decoded.data);
|
|
|
|
break;
|
|
}
|
|
|
|
free(key);
|
|
free(langtag);
|
|
free(transkey);
|
|
ucvector_cleanup(&decoded);
|
|
if(decoder->error) break;
|
|
}
|
|
}
|
|
else if(LodePNG_chunk_type_equals(chunk, "tIME"))
|
|
{
|
|
if(chunkLength != 7) CERROR_BREAK(decoder->error, 73); /*invalid tIME chunk size*/
|
|
|
|
decoder->infoPng.time_defined = 1;
|
|
decoder->infoPng.time.year = 256 * data[0] + data[+ 1];
|
|
decoder->infoPng.time.month = data[2];
|
|
decoder->infoPng.time.day = data[3];
|
|
decoder->infoPng.time.hour = data[4];
|
|
decoder->infoPng.time.minute = data[5];
|
|
decoder->infoPng.time.second = data[6];
|
|
}
|
|
else if(LodePNG_chunk_type_equals(chunk, "pHYs"))
|
|
{
|
|
if(chunkLength != 9) CERROR_BREAK(decoder->error, 74); /*invalid pHYs chunk size*/
|
|
|
|
decoder->infoPng.phys_defined = 1;
|
|
decoder->infoPng.phys_x = 16777216 * data[0] + 65536 * data[1] + 256 * data[2] + data[3];
|
|
decoder->infoPng.phys_y = 16777216 * data[4] + 65536 * data[5] + 256 * data[6] + data[7];
|
|
decoder->infoPng.phys_unit = data[8];
|
|
}
|
|
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
|
|
else /*it's not an implemented chunk type, so ignore it: skip over the data*/
|
|
{
|
|
/*error: unknown critical chunk (5th bit of first byte of chunk type is 0)*/
|
|
if(LodePNG_chunk_critical(chunk)) CERROR_BREAK(decoder->error, 69);
|
|
|
|
unknown = 1;
|
|
#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS
|
|
if(decoder->settings.rememberUnknownChunks)
|
|
{
|
|
LodePNG_UnknownChunks* unknown = &decoder->infoPng.unknown_chunks;
|
|
decoder->error = LodePNG_append_chunk(&unknown->data[critical_pos - 1],
|
|
&unknown->datasize[critical_pos - 1], chunk);
|
|
if(decoder->error) break;
|
|
}
|
|
#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/
|
|
}
|
|
|
|
if(!decoder->settings.ignoreCrc && !unknown) /*check CRC if wanted, only on known chunk types*/
|
|
{
|
|
if(LodePNG_chunk_check_crc(chunk)) CERROR_BREAK(decoder->error, 57); /*invalid CRC*/
|
|
}
|
|
|
|
if(!IEND) chunk = LodePNG_chunk_next_const(chunk);
|
|
}
|
|
|
|
if(!decoder->error)
|
|
{
|
|
ucvector scanlines;
|
|
ucvector_init(&scanlines);
|
|
|
|
/*maximum final image length is already reserved in the vector's length - this is not really necessary*/
|
|
if(!ucvector_resize(&scanlines, ((decoder->infoPng.width * (decoder->infoPng.height
|
|
* LodePNG_InfoColor_getBpp(&decoder->infoPng.color) + 7)) / 8) + decoder->infoPng.height))
|
|
{
|
|
decoder->error = 9945; /*alloc fail*/
|
|
}
|
|
if(!decoder->error)
|
|
{
|
|
/*decompress with the Zlib decompressor*/
|
|
decoder->error = LodePNG_zlib_decompress(&scanlines.data, &scanlines.size, idat.data,
|
|
idat.size, &decoder->settings.zlibsettings);
|
|
}
|
|
|
|
if(!decoder->error)
|
|
{
|
|
ucvector outv;
|
|
ucvector_init(&outv);
|
|
if(!ucvector_resizev(&outv, (decoder->infoPng.height * decoder->infoPng.width
|
|
* LodePNG_InfoColor_getBpp(&decoder->infoPng.color) + 7) / 8, 0)) decoder->error = 9946; /*alloc fail*/
|
|
if(!decoder->error) decoder->error = postProcessScanlines(outv.data, scanlines.data, &decoder->infoPng);
|
|
*out = outv.data;
|
|
*outsize = outv.size;
|
|
}
|
|
ucvector_cleanup(&scanlines);
|
|
}
|
|
|
|
ucvector_cleanup(&idat);
|
|
}
|
|
|
|
void LodePNG_Decoder_decode(LodePNG_Decoder* decoder, unsigned char** out, size_t* outsize,
|
|
const unsigned char* in, size_t insize)
|
|
{
|
|
*out = 0;
|
|
*outsize = 0;
|
|
decodeGeneric(decoder, out, outsize, in, insize);
|
|
if(decoder->error) return;
|
|
if(!decoder->settings.color_convert || LodePNG_InfoColor_equal(&decoder->infoRaw.color, &decoder->infoPng.color))
|
|
{
|
|
/*same color type, no copying or converting of data needed*/
|
|
/*store the infoPng color settings on the infoRaw so that the infoRaw still reflects what colorType
|
|
the raw image has to the end user*/
|
|
if(!decoder->settings.color_convert)
|
|
{
|
|
decoder->error = LodePNG_InfoColor_copy(&decoder->infoRaw.color, &decoder->infoPng.color);
|
|
if(decoder->error) return;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/*color conversion needed; sort of copy of the data*/
|
|
unsigned char* data = *out;
|
|
|
|
/*TODO: check if this works according to the statement in the documentation: "The converter can convert
|
|
from greyscale input color type, to 8-bit greyscale or greyscale with alpha"*/
|
|
if(!(decoder->infoRaw.color.colorType == 2 || decoder->infoRaw.color.colorType == 6)
|
|
&& !(decoder->infoRaw.color.bitDepth == 8))
|
|
{
|
|
decoder->error = 56; /*unsupported color mode conversion*/
|
|
return;
|
|
}
|
|
|
|
*outsize = (decoder->infoPng.width * decoder->infoPng.height
|
|
* LodePNG_InfoColor_getBpp(&decoder->infoRaw.color) + 7) / 8;
|
|
*out = (unsigned char*)malloc(*outsize);
|
|
if(!(*out))
|
|
{
|
|
decoder->error = 9947; /*alloc fail*/
|
|
*outsize = 0;
|
|
}
|
|
else decoder->error = LodePNG_convert(*out, data, &decoder->infoRaw.color, &decoder->infoPng.color,
|
|
decoder->infoPng.width, decoder->infoPng.height);
|
|
free(data);
|
|
}
|
|
}
|
|
|
|
unsigned LodePNG_decode(unsigned char** out, unsigned* w, unsigned* h, const unsigned char* in,
|
|
size_t insize, unsigned colorType, unsigned bitDepth)
|
|
{
|
|
unsigned error;
|
|
size_t dummy_size;
|
|
LodePNG_Decoder decoder;
|
|
LodePNG_Decoder_init(&decoder);
|
|
decoder.infoRaw.color.colorType = colorType;
|
|
decoder.infoRaw.color.bitDepth = bitDepth;
|
|
LodePNG_Decoder_decode(&decoder, out, &dummy_size, in, insize);
|
|
error = decoder.error;
|
|
*w = decoder.infoPng.width;
|
|
*h = decoder.infoPng.height;
|
|
LodePNG_Decoder_cleanup(&decoder);
|
|
return error;
|
|
}
|
|
|
|
unsigned LodePNG_decode32(unsigned char** out, unsigned* w, unsigned* h, const unsigned char* in, size_t insize)
|
|
{
|
|
return LodePNG_decode(out, w, h, in, insize, 6, 8);
|
|
}
|
|
|
|
unsigned LodePNG_decode24(unsigned char** out, unsigned* w, unsigned* h, const unsigned char* in, size_t insize)
|
|
{
|
|
return LodePNG_decode(out, w, h, in, insize, 2, 8);
|
|
}
|
|
|
|
#ifdef LODEPNG_COMPILE_DISK
|
|
unsigned LodePNG_decode_file(unsigned char** out, unsigned* w, unsigned* h, const char* filename,
|
|
unsigned colorType, unsigned bitDepth)
|
|
{
|
|
unsigned char* buffer;
|
|
size_t buffersize;
|
|
unsigned error;
|
|
error = LodePNG_loadFile(&buffer, &buffersize, filename);
|
|
if(!error) error = LodePNG_decode(out, w, h, buffer, buffersize, colorType, bitDepth);
|
|
free(buffer);
|
|
return error;
|
|
}
|
|
|
|
unsigned LodePNG_decode32_file(unsigned char** out, unsigned* w, unsigned* h, const char* filename)
|
|
{
|
|
return LodePNG_decode_file(out, w, h, filename, 6, 8);
|
|
}
|
|
|
|
unsigned LodePNG_decode24_file(unsigned char** out, unsigned* w, unsigned* h, const char* filename)
|
|
{
|
|
return LodePNG_decode_file(out, w, h, filename, 2, 8);
|
|
}
|
|
#endif /*LODEPNG_COMPILE_DISK*/
|
|
|
|
void LodePNG_DecodeSettings_init(LodePNG_DecodeSettings* settings)
|
|
{
|
|
settings->color_convert = 1;
|
|
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
|
|
settings->readTextChunks = 1;
|
|
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
|
|
settings->ignoreCrc = 0;
|
|
#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS
|
|
settings->rememberUnknownChunks = 0;
|
|
#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/
|
|
LodePNG_DecompressSettings_init(&settings->zlibsettings);
|
|
}
|
|
|
|
void LodePNG_Decoder_init(LodePNG_Decoder* decoder)
|
|
{
|
|
LodePNG_DecodeSettings_init(&decoder->settings);
|
|
LodePNG_InfoRaw_init(&decoder->infoRaw);
|
|
LodePNG_InfoPng_init(&decoder->infoPng);
|
|
decoder->error = 1;
|
|
}
|
|
|
|
void LodePNG_Decoder_cleanup(LodePNG_Decoder* decoder)
|
|
{
|
|
LodePNG_InfoRaw_cleanup(&decoder->infoRaw);
|
|
LodePNG_InfoPng_cleanup(&decoder->infoPng);
|
|
}
|
|
|
|
void LodePNG_Decoder_copy(LodePNG_Decoder* dest, const LodePNG_Decoder* source)
|
|
{
|
|
LodePNG_Decoder_cleanup(dest);
|
|
*dest = *source;
|
|
LodePNG_InfoRaw_init(&dest->infoRaw);
|
|
LodePNG_InfoPng_init(&dest->infoPng);
|
|
dest->error = LodePNG_InfoRaw_copy(&dest->infoRaw, &source->infoRaw); if(dest->error) return;
|
|
dest->error = LodePNG_InfoPng_copy(&dest->infoPng, &source->infoPng); if(dest->error) return;
|
|
}
|
|
|
|
#endif /*LODEPNG_COMPILE_DECODER*/
|
|
|
|
#ifdef LODEPNG_COMPILE_ENCODER
|
|
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
/* / PNG Encoder / */
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
|
|
/*chunkName must be string of 4 characters*/
|
|
static unsigned addChunk(ucvector* out, const char* chunkName, const unsigned char* data, size_t length)
|
|
{
|
|
unsigned error = LodePNG_create_chunk(&out->data, &out->size, (unsigned)length, chunkName, data);
|
|
if(error) return error;
|
|
out->allocsize = out->size; /*fix the allocsize again*/
|
|
return 0;
|
|
}
|
|
|
|
static void writeSignature(ucvector* out)
|
|
{
|
|
/*8 bytes PNG signature, aka the magic bytes*/
|
|
ucvector_push_back(out, 137);
|
|
ucvector_push_back(out, 80);
|
|
ucvector_push_back(out, 78);
|
|
ucvector_push_back(out, 71);
|
|
ucvector_push_back(out, 13);
|
|
ucvector_push_back(out, 10);
|
|
ucvector_push_back(out, 26);
|
|
ucvector_push_back(out, 10);
|
|
}
|
|
|
|
static unsigned addChunk_IHDR(ucvector* out, unsigned w, unsigned h, unsigned bitDepth,
|
|
unsigned colorType, unsigned interlaceMethod)
|
|
{
|
|
unsigned error = 0;
|
|
ucvector header;
|
|
ucvector_init(&header);
|
|
|
|
LodePNG_add32bitInt(&header, w); /*width*/
|
|
LodePNG_add32bitInt(&header, h); /*height*/
|
|
ucvector_push_back(&header, (unsigned char)bitDepth); /*bit depth*/
|
|
ucvector_push_back(&header, (unsigned char)colorType); /*color type*/
|
|
ucvector_push_back(&header, 0); /*compression method*/
|
|
ucvector_push_back(&header, 0); /*filter method*/
|
|
ucvector_push_back(&header, interlaceMethod); /*interlace method*/
|
|
|
|
error = addChunk(out, "IHDR", header.data, header.size);
|
|
ucvector_cleanup(&header);
|
|
|
|
return error;
|
|
}
|
|
|
|
static unsigned addChunk_PLTE(ucvector* out, const LodePNG_InfoColor* info)
|
|
{
|
|
unsigned error = 0;
|
|
size_t i;
|
|
ucvector PLTE;
|
|
ucvector_init(&PLTE);
|
|
for(i = 0; i < info->palettesize * 4; i++)
|
|
{
|
|
/*add all channels except alpha channel*/
|
|
if(i % 4 != 3) ucvector_push_back(&PLTE, info->palette[i]);
|
|
}
|
|
error = addChunk(out, "PLTE", PLTE.data, PLTE.size);
|
|
ucvector_cleanup(&PLTE);
|
|
|
|
return error;
|
|
}
|
|
|
|
static unsigned addChunk_tRNS(ucvector* out, const LodePNG_InfoColor* info)
|
|
{
|
|
unsigned error = 0;
|
|
size_t i;
|
|
ucvector tRNS;
|
|
ucvector_init(&tRNS);
|
|
if(info->colorType == 3)
|
|
{
|
|
/*add only alpha channel*/
|
|
for(i = 0; i < info->palettesize; i++) ucvector_push_back(&tRNS, info->palette[4 * i + 3]);
|
|
}
|
|
else if(info->colorType == 0)
|
|
{
|
|
if(info->key_defined)
|
|
{
|
|
ucvector_push_back(&tRNS, (unsigned char)(info->key_r / 256));
|
|
ucvector_push_back(&tRNS, (unsigned char)(info->key_r % 256));
|
|
}
|
|
}
|
|
else if(info->colorType == 2)
|
|
{
|
|
if(info->key_defined)
|
|
{
|
|
ucvector_push_back(&tRNS, (unsigned char)(info->key_r / 256));
|
|
ucvector_push_back(&tRNS, (unsigned char)(info->key_r % 256));
|
|
ucvector_push_back(&tRNS, (unsigned char)(info->key_g / 256));
|
|
ucvector_push_back(&tRNS, (unsigned char)(info->key_g % 256));
|
|
ucvector_push_back(&tRNS, (unsigned char)(info->key_b / 256));
|
|
ucvector_push_back(&tRNS, (unsigned char)(info->key_b % 256));
|
|
}
|
|
}
|
|
|
|
error = addChunk(out, "tRNS", tRNS.data, tRNS.size);
|
|
ucvector_cleanup(&tRNS);
|
|
|
|
return error;
|
|
}
|
|
|
|
static unsigned addChunk_IDAT(ucvector* out, const unsigned char* data, size_t datasize,
|
|
LodePNG_CompressSettings* zlibsettings)
|
|
{
|
|
ucvector zlibdata;
|
|
unsigned error = 0;
|
|
|
|
/*compress with the Zlib compressor*/
|
|
ucvector_init(&zlibdata);
|
|
error = LodePNG_zlib_compress(&zlibdata.data, &zlibdata.size, data, datasize, zlibsettings);
|
|
if(!error) error = addChunk(out, "IDAT", zlibdata.data, zlibdata.size);
|
|
ucvector_cleanup(&zlibdata);
|
|
|
|
return error;
|
|
}
|
|
|
|
static unsigned addChunk_IEND(ucvector* out)
|
|
{
|
|
unsigned error = 0;
|
|
error = addChunk(out, "IEND", 0, 0);
|
|
return error;
|
|
}
|
|
|
|
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
|
|
|
|
static unsigned addChunk_tEXt(ucvector* out, const char* keyword, const char* textstring)
|
|
{
|
|
unsigned error = 0;
|
|
size_t i;
|
|
ucvector text;
|
|
ucvector_init(&text);
|
|
for(i = 0; keyword[i] != 0; i++) ucvector_push_back(&text, (unsigned char)keyword[i]);
|
|
ucvector_push_back(&text, 0);
|
|
for(i = 0; textstring[i] != 0; i++) ucvector_push_back(&text, (unsigned char)textstring[i]);
|
|
error = addChunk(out, "tEXt", text.data, text.size);
|
|
ucvector_cleanup(&text);
|
|
|
|
return error;
|
|
}
|
|
|
|
static unsigned addChunk_zTXt(ucvector* out, const char* keyword, const char* textstring,
|
|
LodePNG_CompressSettings* zlibsettings)
|
|
{
|
|
unsigned error = 0;
|
|
ucvector data, compressed;
|
|
size_t i, textsize = strlen(textstring);
|
|
|
|
ucvector_init(&data);
|
|
ucvector_init(&compressed);
|
|
for(i = 0; keyword[i] != 0; i++) ucvector_push_back(&data, (unsigned char)keyword[i]);
|
|
ucvector_push_back(&data, 0); /* 0 termination char*/
|
|
ucvector_push_back(&data, 0); /*compression method: 0*/
|
|
|
|
error = LodePNG_zlib_compress(&compressed.data, &compressed.size,
|
|
(unsigned char*)textstring, textsize, zlibsettings);
|
|
if(!error)
|
|
{
|
|
for(i = 0; i < compressed.size; i++) ucvector_push_back(&data, compressed.data[i]);
|
|
error = addChunk(out, "zTXt", data.data, data.size);
|
|
}
|
|
|
|
ucvector_cleanup(&compressed);
|
|
ucvector_cleanup(&data);
|
|
return error;
|
|
}
|
|
|
|
static unsigned addChunk_iTXt(ucvector* out, unsigned compressed, const char* keyword, const char* langtag,
|
|
const char* transkey, const char* textstring, LodePNG_CompressSettings* zlibsettings)
|
|
{
|
|
unsigned error = 0;
|
|
ucvector data, compressed_data;
|
|
size_t i, textsize = strlen(textstring);
|
|
|
|
ucvector_init(&data);
|
|
|
|
for(i = 0; keyword[i] != 0; i++) ucvector_push_back(&data, (unsigned char)keyword[i]);
|
|
ucvector_push_back(&data, 0); /*null termination char*/
|
|
ucvector_push_back(&data, compressed ? 1 : 0); /*compression flag*/
|
|
ucvector_push_back(&data, 0); /*compression method*/
|
|
for(i = 0; langtag[i] != 0; i++) ucvector_push_back(&data, (unsigned char)langtag[i]);
|
|
ucvector_push_back(&data, 0); /*null termination char*/
|
|
for(i = 0; transkey[i] != 0; i++) ucvector_push_back(&data, (unsigned char)transkey[i]);
|
|
ucvector_push_back(&data, 0); /*null termination char*/
|
|
|
|
if(compressed)
|
|
{
|
|
ucvector_init(&compressed_data);
|
|
error = LodePNG_zlib_compress(&compressed_data.data, &compressed_data.size,
|
|
(unsigned char*)textstring, textsize, zlibsettings);
|
|
if(!error)
|
|
{
|
|
for(i = 0; i < compressed_data.size; i++) ucvector_push_back(&data, compressed_data.data[i]);
|
|
for(i = 0; textstring[i] != 0; i++) ucvector_push_back(&data, (unsigned char)textstring[i]);
|
|
}
|
|
}
|
|
else /*not compressed*/
|
|
{
|
|
for(i = 0; textstring[i] != 0; i++) ucvector_push_back(&data, (unsigned char)textstring[i]);
|
|
}
|
|
|
|
if(!error) error = addChunk(out, "iTXt", data.data, data.size);
|
|
ucvector_cleanup(&data);
|
|
return error;
|
|
}
|
|
|
|
static unsigned addChunk_bKGD(ucvector* out, const LodePNG_InfoPng* info)
|
|
{
|
|
unsigned error = 0;
|
|
ucvector bKGD;
|
|
ucvector_init(&bKGD);
|
|
if(info->color.colorType == 0 || info->color.colorType == 4)
|
|
{
|
|
ucvector_push_back(&bKGD, (unsigned char)(info->background_r / 256));
|
|
ucvector_push_back(&bKGD, (unsigned char)(info->background_r % 256));
|
|
}
|
|
else if(info->color.colorType == 2 || info->color.colorType == 6)
|
|
{
|
|
ucvector_push_back(&bKGD, (unsigned char)(info->background_r / 256));
|
|
ucvector_push_back(&bKGD, (unsigned char)(info->background_r % 256));
|
|
ucvector_push_back(&bKGD, (unsigned char)(info->background_g / 256));
|
|
ucvector_push_back(&bKGD, (unsigned char)(info->background_g % 256));
|
|
ucvector_push_back(&bKGD, (unsigned char)(info->background_b / 256));
|
|
ucvector_push_back(&bKGD, (unsigned char)(info->background_b % 256));
|
|
}
|
|
else if(info->color.colorType == 3)
|
|
{
|
|
ucvector_push_back(&bKGD, (unsigned char)(info->background_r % 256)); /*palette index*/
|
|
}
|
|
|
|
error = addChunk(out, "bKGD", bKGD.data, bKGD.size);
|
|
ucvector_cleanup(&bKGD);
|
|
|
|
return error;
|
|
}
|
|
|
|
static unsigned addChunk_tIME(ucvector* out, const LodePNG_Time* time)
|
|
{
|
|
unsigned error = 0;
|
|
unsigned char* data = (unsigned char*)malloc(7);
|
|
if(!data) return 9948; /*alloc fail*/
|
|
data[0] = (unsigned char)(time->year / 256);
|
|
data[1] = (unsigned char)(time->year % 256);
|
|
data[2] = time->month;
|
|
data[3] = time->day;
|
|
data[4] = time->hour;
|
|
data[5] = time->minute;
|
|
data[6] = time->second;
|
|
error = addChunk(out, "tIME", data, 7);
|
|
free(data);
|
|
return error;
|
|
}
|
|
|
|
static unsigned addChunk_pHYs(ucvector* out, const LodePNG_InfoPng* info)
|
|
{
|
|
unsigned error = 0;
|
|
ucvector data;
|
|
ucvector_init(&data);
|
|
|
|
LodePNG_add32bitInt(&data, info->phys_x);
|
|
LodePNG_add32bitInt(&data, info->phys_y);
|
|
ucvector_push_back(&data, info->phys_unit);
|
|
|
|
error = addChunk(out, "pHYs", data.data, data.size);
|
|
ucvector_cleanup(&data);
|
|
|
|
return error;
|
|
}
|
|
|
|
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
|
|
|
|
static void filterScanline(unsigned char* out, const unsigned char* scanline, const unsigned char* prevline,
|
|
size_t length, size_t bytewidth, unsigned char filterType)
|
|
{
|
|
size_t i;
|
|
switch(filterType)
|
|
{
|
|
case 0: /*None*/
|
|
for(i = 0; i < length; i++) out[i] = scanline[i];
|
|
break;
|
|
case 1: /*Sub*/
|
|
if(prevline)
|
|
{
|
|
for(i = 0; i < bytewidth; i++) out[i] = scanline[i];
|
|
for(i = bytewidth; i < length ; i++) out[i] = scanline[i] - scanline[i - bytewidth];
|
|
}
|
|
else
|
|
{
|
|
for(i = 0; i < bytewidth; i++) out[i] = scanline[i];
|
|
for(i = bytewidth; i < length; i++) out[i] = scanline[i] - scanline[i - bytewidth];
|
|
}
|
|
break;
|
|
case 2: /*Up*/
|
|
if(prevline)
|
|
{
|
|
for(i = 0; i < length; i++) out[i] = scanline[i] - prevline[i];
|
|
}
|
|
else
|
|
{
|
|
for(i = 0; i < length; i++) out[i] = scanline[i];
|
|
}
|
|
break;
|
|
case 3: /*Average*/
|
|
if(prevline)
|
|
{
|
|
for(i = 0; i < bytewidth; i++) out[i] = scanline[i] - prevline[i] / 2;
|
|
for(i = bytewidth; i < length; i++) out[i] = scanline[i] - ((scanline[i - bytewidth] + prevline[i]) / 2);
|
|
}
|
|
else
|
|
{
|
|
for(i = 0; i < bytewidth; i++) out[i] = scanline[i];
|
|
for(i = bytewidth; i < length; i++) out[i] = scanline[i] - scanline[i - bytewidth] / 2;
|
|
}
|
|
break;
|
|
case 4: /*Paeth*/
|
|
if(prevline)
|
|
{
|
|
/*paethPredictor(0, prevline[i], 0) is always prevline[i]*/
|
|
for(i = 0; i < bytewidth; i++) out[i] = (scanline[i] - prevline[i]);
|
|
for(i = bytewidth; i < length; i++)
|
|
{
|
|
out[i] = (scanline[i] - paethPredictor(scanline[i - bytewidth], prevline[i], prevline[i - bytewidth]));
|
|
}
|
|
}
|
|
else
|
|
{
|
|
for(i = 0; i < bytewidth; i++) out[i] = scanline[i];
|
|
/*paethPredictor(scanline[i - bytewidth], 0, 0) is always scanline[i - bytewidth]*/
|
|
for(i = bytewidth; i < length; i++) out[i] = (scanline[i] - scanline[i - bytewidth]);
|
|
}
|
|
break;
|
|
default: return; /*unexisting filter type given*/
|
|
}
|
|
}
|
|
|
|
static unsigned filter(unsigned char* out, const unsigned char* in, unsigned w, unsigned h,
|
|
const LodePNG_InfoColor* info, const LodePNG_EncodeSettings* settings)
|
|
{
|
|
/*
|
|
For PNG filter method 0
|
|
out must be a buffer with as size: h + (w * h * bpp + 7) / 8, because there are
|
|
the scanlines with 1 extra byte per scanline
|
|
*/
|
|
|
|
unsigned bpp = LodePNG_InfoColor_getBpp(info);
|
|
/*the width of a scanline in bytes, not including the filter type*/
|
|
size_t linebytes = (w * bpp + 7) / 8;
|
|
/*bytewidth is used for filtering, is 1 when bpp < 8, number of bytes per pixel otherwise*/
|
|
size_t bytewidth = (bpp + 7) / 8;
|
|
const unsigned char* prevline = 0;
|
|
unsigned x, y;
|
|
unsigned error = 0;
|
|
|
|
if(bpp == 0) return 31; /*error: invalid color type*/
|
|
|
|
if(!settings->bruteForceFilters)
|
|
{
|
|
/*
|
|
There is a heuristic called the minimum sum of absolute differences heuristic, suggested by the PNG standard:
|
|
* If the image type is Palette, or the bit depth is smaller than 8, then do not filter the image (i.e.
|
|
use fixed filtering, with the filter None).
|
|
* (The other case) If the image type is Grayscale or RGB (with or without Alpha), and the bit depth is
|
|
not smaller than 8, then use adaptive filtering heuristic as follows: independently for each row, apply
|
|
all five filters and select the filter that produces the smallest sum of absolute values per row.
|
|
*/
|
|
if(info->colorType == 3 || info->bitDepth < 8) /*None filtertype for everything*/
|
|
{
|
|
for(y = 0; y < h; y++)
|
|
{
|
|
size_t outindex = (1 + linebytes) * y; /*the extra filterbyte added to each row*/
|
|
size_t inindex = linebytes * y;
|
|
const unsigned TYPE = 0;
|
|
out[outindex] = TYPE; /*filter type byte*/
|
|
filterScanline(&out[outindex + 1], &in[inindex], prevline, linebytes, bytewidth, TYPE);
|
|
prevline = &in[inindex];
|
|
}
|
|
}
|
|
else /*adaptive filtering*/
|
|
{
|
|
size_t sum[5];
|
|
ucvector attempt[5]; /*five filtering attempts, one for each filter type*/
|
|
size_t smallest = 0;
|
|
unsigned type, bestType = 0;
|
|
|
|
for(type = 0; type < 5; type++) ucvector_init(&attempt[type]);
|
|
for(type = 0; type < 5; type++)
|
|
{
|
|
if(!ucvector_resize(&attempt[type], linebytes)) ERROR_BREAK(9949 /*alloc fail*/);
|
|
}
|
|
|
|
if(!error)
|
|
{
|
|
for(y = 0; y < h; y++)
|
|
{
|
|
/*try the 5 filter types*/
|
|
for(type = 0; type < 5; type++)
|
|
{
|
|
filterScanline(attempt[type].data, &in[y * linebytes], prevline, linebytes, bytewidth, type);
|
|
|
|
/*calculate the sum of the result*/
|
|
sum[type] = 0;
|
|
/*note that not all pixels are checked to speed this up while still having probably the best choice*/
|
|
for(x = 0; x < attempt[type].size; x+=3)
|
|
{
|
|
/*For differences, each byte should be treated as signed, values above 127 are negative
|
|
(converted to signed char). Filtertype 0 isn't a difference though, so use unsigned there.
|
|
This means filtertype 0 is almost never chosen, but that is justified.*/
|
|
if(type == 0) sum[type] += (unsigned char)(attempt[type].data[x]);
|
|
else
|
|
{
|
|
signed char s = (signed char)(attempt[type].data[x]);
|
|
sum[type] += s < 0 ? -s : s;
|
|
}
|
|
}
|
|
|
|
/*check if this is smallest sum (or if type == 0 it's the first case so always store the values)*/
|
|
if(type == 0 || sum[type] < smallest)
|
|
{
|
|
bestType = type;
|
|
smallest = sum[type];
|
|
}
|
|
}
|
|
|
|
prevline = &in[y * linebytes];
|
|
|
|
/*now fill the out values*/
|
|
out[y * (linebytes + 1)] = bestType; /*the first byte of a scanline will be the filter type*/
|
|
for(x = 0; x < linebytes; x++) out[y * (linebytes + 1) + 1 + x] = attempt[bestType].data[x];
|
|
}
|
|
}
|
|
|
|
for(type = 0; type < 5; type++) ucvector_cleanup(&attempt[type]);
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/*brute force filter chooser.
|
|
deflate the scanline after every filter attempt to see which one deflates best.
|
|
This is very slow and gives only slightly smaller, sometimes even larger, result*/
|
|
size_t size[5];
|
|
ucvector attempt[5]; /*five filtering attempts, one for each filter type*/
|
|
size_t smallest;
|
|
unsigned type = 0, bestType = 0;
|
|
unsigned char* dummy;
|
|
LodePNG_CompressSettings zlibsettings = settings->zlibsettings;
|
|
/*use fixed tree on the attempts so that the tree is not adapted to the filtertype on purpose,
|
|
to simulate the true case where the tree is the same for the whole image. Sometimes it gives
|
|
better result with dynamic tree anyway. Using the fixed tree sometimes gives worse, but in rare
|
|
cases better compression. It does make this a bit less slow, so it's worth doing this.*/
|
|
zlibsettings.btype = 1;
|
|
for(type = 0; type < 5; type++)
|
|
{
|
|
ucvector_init(&attempt[type]);
|
|
ucvector_resize(&attempt[type], linebytes); /*todo: give error if resize failed*/
|
|
}
|
|
for(y = 0; y < h; y++) /*try the 5 filter types*/
|
|
{
|
|
for(type = 0; type < 5; type++)
|
|
{
|
|
unsigned testsize = attempt[type].size;
|
|
/*unsigned testsize = attempt[type].size / 8;*/ /*it already works good enough by testing a part of the row*/
|
|
/*if(testsize == 0) testsize = attempt[type].size;*/
|
|
|
|
filterScanline(attempt[type].data, &in[y * linebytes], prevline, linebytes, bytewidth, type);
|
|
size[type] = 0;
|
|
dummy = 0;
|
|
LodePNG_zlib_compress(&dummy, &size[type], attempt[type].data, testsize, &zlibsettings);
|
|
free(dummy);
|
|
/*check if this is smallest size (or if type == 0 it's the first case so always store the values)*/
|
|
if(type == 0 || size[type] < smallest)
|
|
{
|
|
bestType = type;
|
|
smallest = size[type];
|
|
}
|
|
}
|
|
prevline = &in[y * linebytes];
|
|
out[y * (linebytes + 1)] = bestType; /*the first byte of a scanline will be the filter type*/
|
|
for(x = 0; x < linebytes; x++) out[y * (linebytes + 1) + 1 + x] = attempt[bestType].data[x];
|
|
}
|
|
for(type = 0; type < 5; type++) ucvector_cleanup(&attempt[type]);
|
|
}
|
|
|
|
return error;
|
|
}
|
|
|
|
static void addPaddingBits(unsigned char* out, const unsigned char* in,
|
|
size_t olinebits, size_t ilinebits, unsigned h)
|
|
{
|
|
/*The opposite of the removePaddingBits function
|
|
olinebits must be >= ilinebits*/
|
|
unsigned y;
|
|
size_t diff = olinebits - ilinebits;
|
|
size_t obp = 0, ibp = 0; /*bit pointers*/
|
|
for(y = 0; y < h; y++)
|
|
{
|
|
size_t x;
|
|
for(x = 0; x < ilinebits; x++)
|
|
{
|
|
unsigned char bit = readBitFromReversedStream(&ibp, in);
|
|
setBitOfReversedStream(&obp, out, bit);
|
|
}
|
|
/*obp += diff; --> no, fill in some value in the padding bits too, to avoid
|
|
"Use of uninitialised value of size ###" warning from valgrind*/
|
|
for(x = 0; x < diff; x++) setBitOfReversedStream(&obp, out, 0);
|
|
}
|
|
}
|
|
|
|
static void Adam7_interlace(unsigned char* out, const unsigned char* in, unsigned w, unsigned h, unsigned bpp)
|
|
{
|
|
/*Note: this function works on image buffers WITHOUT padding bits at end of scanlines with non-multiple-of-8
|
|
bit amounts, only between reduced images is padding*/
|
|
unsigned passw[7], passh[7];
|
|
size_t filter_passstart[8], padded_passstart[8], passstart[8];
|
|
unsigned i;
|
|
|
|
Adam7_getpassvalues(passw, passh, filter_passstart, padded_passstart, passstart, w, h, bpp);
|
|
|
|
if(bpp >= 8)
|
|
{
|
|
for(i = 0; i < 7; i++)
|
|
{
|
|
unsigned x, y, b;
|
|
size_t bytewidth = bpp / 8;
|
|
for(y = 0; y < passh[i]; y++)
|
|
for(x = 0; x < passw[i]; x++)
|
|
{
|
|
size_t pixelinstart = ((ADAM7_IY[i] + y * ADAM7_DY[i]) * w + ADAM7_IX[i] + x * ADAM7_DX[i]) * bytewidth;
|
|
size_t pixeloutstart = passstart[i] + (y * passw[i] + x) * bytewidth;
|
|
for(b = 0; b < bytewidth; b++)
|
|
{
|
|
out[pixeloutstart + b] = in[pixelinstart + b];
|
|
}
|
|
}
|
|
}
|
|
}
|
|
else /*bpp < 8: Adam7 with pixels < 8 bit is a bit trickier: with bit pointers*/
|
|
{
|
|
for(i = 0; i < 7; i++)
|
|
{
|
|
unsigned x, y, b;
|
|
unsigned ilinebits = bpp * passw[i];
|
|
unsigned olinebits = bpp * w;
|
|
size_t obp, ibp; /*bit pointers (for out and in buffer)*/
|
|
for(y = 0; y < passh[i]; y++)
|
|
for(x = 0; x < passw[i]; x++)
|
|
{
|
|
ibp = (ADAM7_IY[i] + y * ADAM7_DY[i]) * olinebits + (ADAM7_IX[i] + x * ADAM7_DX[i]) * bpp;
|
|
obp = (8 * passstart[i]) + (y * ilinebits + x * bpp);
|
|
for(b = 0; b < bpp; b++)
|
|
{
|
|
unsigned char bit = readBitFromReversedStream(&ibp, in);
|
|
setBitOfReversedStream(&obp, out, bit);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/*out must be buffer big enough to contain uncompressed IDAT chunk data, and in must contain the full image.
|
|
return value is error**/
|
|
static unsigned preProcessScanlines(unsigned char** out, size_t* outsize, const unsigned char* in,
|
|
const LodePNG_InfoPng* infoPng, const LodePNG_EncodeSettings* settings)
|
|
{
|
|
/*
|
|
This function converts the pure 2D image with the PNG's colortype, into filtered-padded-interlaced data. Steps:
|
|
*) if no Adam7: 1) add padding bits (= posible extra bits per scanline if bpp < 8) 2) filter
|
|
*) if adam7: 1) Adam7_interlace 2) 7x add padding bits 3) 7x filter
|
|
*/
|
|
unsigned bpp = LodePNG_InfoColor_getBpp(&infoPng->color);
|
|
unsigned w = infoPng->width;
|
|
unsigned h = infoPng->height;
|
|
unsigned error = 0;
|
|
|
|
if(infoPng->interlaceMethod == 0)
|
|
{
|
|
*outsize = h + (h * ((w * bpp + 7) / 8)); /*image size plus an extra byte per scanline + possible padding bits*/
|
|
*out = (unsigned char*)malloc(*outsize);
|
|
if(!(*out) && (*outsize)) error = 9950; /*alloc fail*/
|
|
|
|
if(!error)
|
|
{
|
|
/*non multiple of 8 bits per scanline, padding bits needed per scanline*/
|
|
if(bpp < 8 && w * bpp != ((w * bpp + 7) / 8) * 8)
|
|
{
|
|
ucvector padded;
|
|
ucvector_init(&padded);
|
|
if(!ucvector_resize(&padded, h * ((w * bpp + 7) / 8))) error = 9951; /*alloc fail*/
|
|
if(!error)
|
|
{
|
|
addPaddingBits(padded.data, in, ((w * bpp + 7) / 8) * 8, w * bpp, h);
|
|
error = filter(*out, padded.data, w, h, &infoPng->color, settings);
|
|
}
|
|
ucvector_cleanup(&padded);
|
|
}
|
|
else
|
|
{
|
|
/*we can immediatly filter into the out buffer, no other steps needed*/
|
|
error = filter(*out, in, w, h, &infoPng->color, settings);
|
|
}
|
|
}
|
|
}
|
|
else /*interlaceMethod is 1 (Adam7)*/
|
|
{
|
|
unsigned char* adam7 = (unsigned char*)malloc((h * w * bpp + 7) / 8);
|
|
if(!adam7 && ((h * w * bpp + 7) / 8)) error = 9952; /*alloc fail*/
|
|
|
|
while(!error) /*not a real while loop, used to break out to cleanup to avoid a goto*/
|
|
{
|
|
unsigned passw[7], passh[7];
|
|
size_t filter_passstart[8], padded_passstart[8], passstart[8];
|
|
unsigned i;
|
|
|
|
Adam7_getpassvalues(passw, passh, filter_passstart, padded_passstart, passstart, w, h, bpp);
|
|
|
|
*outsize = filter_passstart[7]; /*image size plus an extra byte per scanline + possible padding bits*/
|
|
*out = (unsigned char*)malloc(*outsize);
|
|
if(!(*out) && (*outsize)) ERROR_BREAK(9953 /*alloc fail*/);
|
|
|
|
Adam7_interlace(adam7, in, w, h, bpp);
|
|
|
|
for(i = 0; i < 7; i++)
|
|
{
|
|
if(bpp < 8)
|
|
{
|
|
ucvector padded;
|
|
ucvector_init(&padded);
|
|
if(!ucvector_resize(&padded, h * ((w * bpp + 7) / 8))) error = 9954; /*alloc fail*/
|
|
if(!error)
|
|
{
|
|
addPaddingBits(&padded.data[padded_passstart[i]], &adam7[passstart[i]],
|
|
((passw[i] * bpp + 7) / 8) * 8, passw[i] * bpp, passh[i]);
|
|
error = filter(&(*out)[filter_passstart[i]], &padded.data[padded_passstart[i]],
|
|
passw[i], passh[i], &infoPng->color, settings);
|
|
}
|
|
|
|
ucvector_cleanup(&padded);
|
|
}
|
|
else
|
|
{
|
|
error = filter(&(*out)[filter_passstart[i]], &adam7[padded_passstart[i]],
|
|
passw[i], passh[i], &infoPng->color, settings);
|
|
}
|
|
}
|
|
|
|
break;
|
|
}
|
|
|
|
free(adam7);
|
|
}
|
|
|
|
return error;
|
|
}
|
|
|
|
/*palette must have 4 * palettesize bytes allocated, and given in format RGBARGBARGBARGBA...*/
|
|
static unsigned isPaletteFullyOpaque(const unsigned char* palette, size_t palettesize)
|
|
{
|
|
size_t i;
|
|
for(i = 0; i < palettesize; i++)
|
|
{
|
|
if(palette[4 * i + 3] != 255) return 0;
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
/*this function checks if the input image given by the user has no transparent pixels*/
|
|
static unsigned isFullyOpaque(const unsigned char* image, unsigned w, unsigned h, const LodePNG_InfoColor* info)
|
|
{
|
|
/*TODO: When the user specified a color key for the input image, then this function must
|
|
also check for pixels that are the same as the color key and treat those as transparent.*/
|
|
|
|
unsigned i, numpixels = w * h;
|
|
if(info->colorType == 6)
|
|
{
|
|
if(info->bitDepth == 8)
|
|
{
|
|
for(i = 0; i < numpixels; i++)
|
|
{
|
|
if(image[i * 4 + 3] != 255) return 0;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
for(i = 0; i < numpixels; i++)
|
|
{
|
|
if(image[i * 8 + 6] != 255 || image[i * 8 + 7] != 255) return 0;
|
|
}
|
|
}
|
|
return 1; /*no single pixel with alpha channel other than 255 found*/
|
|
}
|
|
else if(info->colorType == 4)
|
|
{
|
|
if(info->bitDepth == 8)
|
|
{
|
|
for(i = 0; i < numpixels; i++)
|
|
{
|
|
if(image[i * 2 + 1] != 255) return 0;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
for(i = 0; i < numpixels; i++)
|
|
{
|
|
if(image[i * 4 + 2] != 255 || image[i * 4 + 3] != 255) return 0;
|
|
}
|
|
}
|
|
return 1; /*no single pixel with alpha channel other than 255 found*/
|
|
}
|
|
else if(info->colorType == 3)
|
|
{
|
|
/*when there's a palette, we could check every pixel for translucency,
|
|
but much quicker is to just check the palette*/
|
|
return(isPaletteFullyOpaque(info->palette, info->palettesize));
|
|
}
|
|
|
|
return 0; /*color type that isn't supported by this function yet, so assume there is transparency to be safe*/
|
|
}
|
|
|
|
#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS
|
|
static unsigned addUnknownChunks(ucvector* out, unsigned char* data, size_t datasize)
|
|
{
|
|
unsigned char* inchunk = data;
|
|
while((size_t)(inchunk - data) < datasize)
|
|
{
|
|
unsigned error = LodePNG_append_chunk(&out->data, &out->size, inchunk);
|
|
if(error) return error; /*error: not enough memory*/
|
|
out->allocsize = out->size; /*fix the allocsize again*/
|
|
inchunk = LodePNG_chunk_next(inchunk);
|
|
}
|
|
return 0;
|
|
}
|
|
#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/
|
|
|
|
void LodePNG_Encoder_encode(LodePNG_Encoder* encoder, unsigned char** out, size_t* outsize,
|
|
const unsigned char* image, unsigned w, unsigned h)
|
|
{
|
|
LodePNG_InfoPng info;
|
|
ucvector outv;
|
|
unsigned char* data = 0; /*uncompressed version of the IDAT chunk data*/
|
|
size_t datasize = 0;
|
|
|
|
/*provide some proper output values if error will happen*/
|
|
*out = 0;
|
|
*outsize = 0;
|
|
encoder->error = 0;
|
|
|
|
/*UNSAFE copy to avoid having to cleanup! but we will only change primitive parameters,
|
|
and not invoke the cleanup function nor touch the palette's buffer so we use it safely*/
|
|
info = encoder->infoPng;
|
|
info.width = w;
|
|
info.height = h;
|
|
|
|
if(encoder->settings.autoLeaveOutAlphaChannel && isFullyOpaque(image, w, h, &encoder->infoRaw.color))
|
|
{
|
|
/*go to a color type without alpha channel*/
|
|
if(info.color.colorType == 6) info.color.colorType = 2;
|
|
else if(info.color.colorType == 4) info.color.colorType = 0;
|
|
}
|
|
|
|
if(encoder->settings.zlibsettings.windowSize > 32768)
|
|
{
|
|
encoder->error = 60; /*error: windowsize larger than allowed*/
|
|
return;
|
|
}
|
|
if(encoder->settings.zlibsettings.btype > 2)
|
|
{
|
|
encoder->error = 61; /*error: unexisting btype*/
|
|
return;
|
|
}
|
|
if(encoder->infoPng.interlaceMethod > 1)
|
|
{
|
|
encoder->error = 71; /*error: unexisting interlace mode*/
|
|
return;
|
|
}
|
|
/*error: unexisting color type given*/
|
|
if((encoder->error = checkColorValidity(info.color.colorType, info.color.bitDepth))) return;
|
|
/*error: unexisting color type given*/
|
|
if((encoder->error = checkColorValidity(encoder->infoRaw.color.colorType, encoder->infoRaw.color.bitDepth))) return;
|
|
|
|
if(!LodePNG_InfoColor_equal(&encoder->infoRaw.color, &info.color))
|
|
{
|
|
unsigned char* converted;
|
|
size_t size = (w * h * LodePNG_InfoColor_getBpp(&info.color) + 7) / 8;
|
|
|
|
if((info.color.colorType != 6 && info.color.colorType != 2) || (info.color.bitDepth != 8))
|
|
{
|
|
encoder->error = 59; /*for the output image, only these types are supported*/
|
|
return;
|
|
}
|
|
converted = (unsigned char*)malloc(size);
|
|
if(!converted && size) encoder->error = 9955; /*alloc fail*/
|
|
if(!encoder->error)
|
|
{
|
|
encoder->error = LodePNG_convert(converted, image, &info.color, &encoder->infoRaw.color, w, h);
|
|
}
|
|
if(!encoder->error) preProcessScanlines(&data, &datasize, converted, &info, &encoder->settings);
|
|
free(converted);
|
|
}
|
|
else preProcessScanlines(&data, &datasize, image, &info, &encoder->settings);
|
|
|
|
ucvector_init(&outv);
|
|
while(!encoder->error) /*while only executed once, to break on error*/
|
|
{
|
|
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
|
|
size_t i;
|
|
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
|
|
/*write signature and chunks*/
|
|
writeSignature(&outv);
|
|
/*IHDR*/
|
|
addChunk_IHDR(&outv, w, h, info.color.bitDepth, info.color.colorType, info.interlaceMethod);
|
|
#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS
|
|
/*unknown chunks between IHDR and PLTE*/
|
|
if(info.unknown_chunks.data[0])
|
|
{
|
|
encoder->error = addUnknownChunks(&outv, info.unknown_chunks.data[0], info.unknown_chunks.datasize[0]);
|
|
if(encoder->error) break;
|
|
}
|
|
#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/
|
|
/*PLTE*/
|
|
if(info.color.colorType == 3)
|
|
{
|
|
if(info.color.palettesize == 0 || info.color.palettesize > 256)
|
|
{
|
|
encoder->error = 68; /*invalid palette size*/
|
|
break;
|
|
}
|
|
addChunk_PLTE(&outv, &info.color);
|
|
}
|
|
if(encoder->settings.force_palette && (info.color.colorType == 2 || info.color.colorType == 6))
|
|
{
|
|
if(info.color.palettesize == 0 || info.color.palettesize > 256)
|
|
{
|
|
encoder->error = 68; /*invalid palette size*/
|
|
break;
|
|
}
|
|
addChunk_PLTE(&outv, &info.color);
|
|
}
|
|
/*tRNS*/
|
|
if(info.color.colorType == 3 && !isPaletteFullyOpaque(info.color.palette, info.color.palettesize))
|
|
{
|
|
addChunk_tRNS(&outv, &info.color);
|
|
}
|
|
if((info.color.colorType == 0 || info.color.colorType == 2) && info.color.key_defined)
|
|
{
|
|
addChunk_tRNS(&outv, &info.color);
|
|
}
|
|
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
|
|
/*bKGD (must come between PLTE and the IDAt chunks*/
|
|
if(info.background_defined) addChunk_bKGD(&outv, &info);
|
|
/*pHYs (must come before the IDAT chunks)*/
|
|
if(info.phys_defined) addChunk_pHYs(&outv, &info);
|
|
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
|
|
#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS
|
|
/*unknown chunks between PLTE and IDAT*/
|
|
if(info.unknown_chunks.data[1])
|
|
{
|
|
encoder->error = addUnknownChunks(&outv, info.unknown_chunks.data[1], info.unknown_chunks.datasize[1]);
|
|
if(encoder->error) break;
|
|
}
|
|
#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/
|
|
/*IDAT (multiple IDAT chunks must be consecutive)*/
|
|
encoder->error = addChunk_IDAT(&outv, data, datasize, &encoder->settings.zlibsettings);
|
|
if(encoder->error) break;
|
|
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
|
|
/*tIME*/
|
|
if(info.time_defined) addChunk_tIME(&outv, &info.time);
|
|
/*tEXt and/or zTXt*/
|
|
for(i = 0; i < info.text.num; i++)
|
|
{
|
|
if(strlen(info.text.keys[i]) > 79)
|
|
{
|
|
encoder->error = 66; /*text chunk too large*/
|
|
break;
|
|
}
|
|
if(strlen(info.text.keys[i]) < 1)
|
|
{
|
|
encoder->error = 67; /*text chunk too small*/
|
|
break;
|
|
}
|
|
if(encoder->settings.text_compression)
|
|
addChunk_zTXt(&outv, info.text.keys[i], info.text.strings[i], &encoder->settings.zlibsettings);
|
|
else
|
|
addChunk_tEXt(&outv, info.text.keys[i], info.text.strings[i]);
|
|
}
|
|
/*LodePNG version id in text chunk*/
|
|
if(encoder->settings.add_id)
|
|
{
|
|
unsigned alread_added_id_text = 0;
|
|
for(i = 0; i < info.text.num; i++)
|
|
{
|
|
if(!strcmp(info.text.keys[i], "LodePNG"))
|
|
{
|
|
alread_added_id_text = 1;
|
|
break;
|
|
}
|
|
}
|
|
if(alread_added_id_text == 0)
|
|
addChunk_tEXt(&outv, "LodePNG", VERSION_STRING); /*it's shorter as tEXt than as zTXt chunk*/
|
|
}
|
|
/*iTXt*/
|
|
for(i = 0; i < info.itext.num; i++)
|
|
{
|
|
if(strlen(info.itext.keys[i]) > 79)
|
|
{
|
|
encoder->error = 66; /*text chunk too large*/
|
|
break;
|
|
}
|
|
if(strlen(info.itext.keys[i]) < 1)
|
|
{
|
|
encoder->error = 67; /*text chunk too small*/
|
|
break;
|
|
}
|
|
addChunk_iTXt(&outv, encoder->settings.text_compression,
|
|
info.itext.keys[i], info.itext.langtags[i], info.itext.transkeys[i], info.itext.strings[i],
|
|
&encoder->settings.zlibsettings);
|
|
}
|
|
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
|
|
#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS
|
|
/*unknown chunks between IDAT and IEND*/
|
|
if(info.unknown_chunks.data[2])
|
|
{
|
|
encoder->error = addUnknownChunks(&outv, info.unknown_chunks.data[2], info.unknown_chunks.datasize[2]);
|
|
if(encoder->error) break;
|
|
}
|
|
#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/
|
|
/*IEND*/
|
|
addChunk_IEND(&outv);
|
|
|
|
break; /*this isn't really a while loop; no error happened so break out now!*/
|
|
}
|
|
|
|
free(data);
|
|
/*instead of cleaning the vector up, give it to the output*/
|
|
*out = outv.data;
|
|
*outsize = outv.size;
|
|
}
|
|
|
|
unsigned LodePNG_encode(unsigned char** out, size_t* outsize, const unsigned char* image,
|
|
unsigned w, unsigned h, unsigned colorType, unsigned bitDepth)
|
|
{
|
|
unsigned error;
|
|
LodePNG_Encoder encoder;
|
|
LodePNG_Encoder_init(&encoder);
|
|
encoder.infoRaw.color.colorType = colorType;
|
|
encoder.infoRaw.color.bitDepth = bitDepth;
|
|
encoder.infoPng.color.colorType = colorType;
|
|
encoder.infoPng.color.bitDepth = bitDepth;
|
|
LodePNG_Encoder_encode(&encoder, out, outsize, image, w, h);
|
|
error = encoder.error;
|
|
LodePNG_Encoder_cleanup(&encoder);
|
|
return error;
|
|
}
|
|
|
|
unsigned LodePNG_encode32(unsigned char** out, size_t* outsize, const unsigned char* image, unsigned w, unsigned h)
|
|
{
|
|
return LodePNG_encode(out, outsize, image, w, h, 6, 8);
|
|
}
|
|
|
|
unsigned LodePNG_encode24(unsigned char** out, size_t* outsize, const unsigned char* image, unsigned w, unsigned h)
|
|
{
|
|
return LodePNG_encode(out, outsize, image, w, h, 2, 8);
|
|
}
|
|
|
|
#ifdef LODEPNG_COMPILE_DISK
|
|
unsigned LodePNG_encode_file(const char* filename, const unsigned char* image, unsigned w, unsigned h,
|
|
unsigned colorType, unsigned bitDepth)
|
|
{
|
|
unsigned char* buffer;
|
|
size_t buffersize;
|
|
unsigned error = LodePNG_encode(&buffer, &buffersize, image, w, h, colorType, bitDepth);
|
|
if(!error) error = LodePNG_saveFile(buffer, buffersize, filename);
|
|
free(buffer);
|
|
return error;
|
|
}
|
|
|
|
unsigned LodePNG_encode32_file(const char* filename, const unsigned char* image, unsigned w, unsigned h)
|
|
{
|
|
return LodePNG_encode_file(filename, image, w, h, 6, 8);
|
|
}
|
|
|
|
unsigned LodePNG_encode24_file(const char* filename, const unsigned char* image, unsigned w, unsigned h)
|
|
{
|
|
return LodePNG_encode_file(filename, image, w, h, 2, 8);
|
|
}
|
|
#endif /*LODEPNG_COMPILE_DISK*/
|
|
|
|
void LodePNG_EncodeSettings_init(LodePNG_EncodeSettings* settings)
|
|
{
|
|
LodePNG_CompressSettings_init(&settings->zlibsettings);
|
|
settings->bruteForceFilters = 0;
|
|
settings->autoLeaveOutAlphaChannel = 1;
|
|
settings->force_palette = 0;
|
|
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
|
|
settings->add_id = 1;
|
|
settings->text_compression = 0;
|
|
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
|
|
}
|
|
|
|
void LodePNG_Encoder_init(LodePNG_Encoder* encoder)
|
|
{
|
|
LodePNG_EncodeSettings_init(&encoder->settings);
|
|
LodePNG_InfoPng_init(&encoder->infoPng);
|
|
LodePNG_InfoRaw_init(&encoder->infoRaw);
|
|
encoder->error = 1;
|
|
}
|
|
|
|
void LodePNG_Encoder_cleanup(LodePNG_Encoder* encoder)
|
|
{
|
|
LodePNG_InfoPng_cleanup(&encoder->infoPng);
|
|
LodePNG_InfoRaw_cleanup(&encoder->infoRaw);
|
|
}
|
|
|
|
void LodePNG_Encoder_copy(LodePNG_Encoder* dest, const LodePNG_Encoder* source)
|
|
{
|
|
LodePNG_Encoder_cleanup(dest);
|
|
*dest = *source;
|
|
LodePNG_InfoPng_init(&dest->infoPng);
|
|
LodePNG_InfoRaw_init(&dest->infoRaw);
|
|
dest->error = LodePNG_InfoPng_copy(&dest->infoPng, &source->infoPng);
|
|
if(dest->error) return;
|
|
dest->error = LodePNG_InfoRaw_copy(&dest->infoRaw, &source->infoRaw);
|
|
if(dest->error) return;
|
|
}
|
|
|
|
#endif /*LODEPNG_COMPILE_ENCODER*/
|
|
|
|
#endif /*LODEPNG_COMPILE_PNG*/
|
|
|
|
#ifdef LODEPNG_COMPILE_ERROR_TEXT
|
|
|
|
/*
|
|
This returns the description of a numerical error code in English. This is also
|
|
the documentation of all the error codes.
|
|
*/
|
|
const char* LodePNG_error_text(unsigned code)
|
|
{
|
|
switch(code)
|
|
{
|
|
case 0: return "no error, everything went ok";
|
|
case 1: return "nothing done yet"; /*the Encoder/Decoder has done nothing yet, error checking makes no sense yet*/
|
|
case 10: return "end of input memory reached without huffman end code"; /*while huffman decoding*/
|
|
case 11: return "error in code tree made it jump outside of huffman tree"; /*while huffman decoding*/
|
|
case 13: return "problem while processing dynamic deflate block";
|
|
case 14: return "problem while processing dynamic deflate block";
|
|
case 15: return "problem while processing dynamic deflate block";
|
|
case 16: return "unexisting code while processing dynamic deflate block";
|
|
case 17: return "end of out buffer memory reached while inflating";
|
|
case 18: return "invalid distance code while inflating";
|
|
case 19: return "end of out buffer memory reached while inflating";
|
|
case 20: return "invalid deflate block BTYPE encountered while decoding";
|
|
case 21: return "NLEN is not ones complement of LEN in a deflate block";
|
|
|
|
/*end of out buffer memory reached while inflating:
|
|
This can happen if the inflated deflate data is longer than the amount of bytes required to fill up
|
|
all the pixels of the image, given the color depth and image dimensions. Something that doesn't
|
|
happen in a normal, well encoded, PNG image.*/
|
|
case 22: return "end of out buffer memory reached while inflating";
|
|
|
|
case 23: return "end of in buffer memory reached while inflating";
|
|
case 24: return "invalid FCHECK in zlib header";
|
|
case 25: return "invalid compression method in zlib header";
|
|
case 26: return "FDICT encountered in zlib header while it's not used for PNG";
|
|
case 27: return "PNG file is smaller than a PNG header";
|
|
/*Checks the magic file header, the first 8 bytes of the PNG file*/
|
|
case 28: return "incorrect PNG signature, it's no PNG or corrupted";
|
|
case 29: return "first chunk is not the header chunk";
|
|
case 30: return "chunk length too large, chunk broken off at end of file";
|
|
case 31: return "illegal PNG color type or bpp";
|
|
case 32: return "illegal PNG compression method";
|
|
case 33: return "illegal PNG filter method";
|
|
case 34: return "illegal PNG interlace method";
|
|
case 35: return "chunk length of a chunk is too large or the chunk too small";
|
|
case 36: return "illegal PNG filter type encountered";
|
|
case 37: return "illegal bit depth for this color type given";
|
|
case 38: return "the palette is too big"; /*more than 256 colors*/
|
|
case 39: return "more palette alpha values given in tRNS chunk than there are colors in the palette";
|
|
case 40: return "tRNS chunk has wrong size for greyscale image";
|
|
case 41: return "tRNS chunk has wrong size for RGB image";
|
|
case 42: return "tRNS chunk appeared while it was not allowed for this color type";
|
|
case 43: return "bKGD chunk has wrong size for palette image";
|
|
case 44: return "bKGD chunk has wrong size for greyscale image";
|
|
case 45: return "bKGD chunk has wrong size for RGB image";
|
|
/*Is the palette too small?*/
|
|
case 46: return "a value in indexed image is larger than the palette size (bitdepth = 8)";
|
|
/*Is the palette too small?*/
|
|
case 47: return "a value in indexed image is larger than the palette size (bitdepth < 8)";
|
|
/*the input data is empty, maybe a PNG file doesn't exist or is in the wrong path*/
|
|
case 48: return "empty input or file doesn't exist";
|
|
case 49: return "jumped past memory while generating dynamic huffman tree";
|
|
case 50: return "jumped past memory while generating dynamic huffman tree";
|
|
case 51: return "jumped past memory while inflating huffman block";
|
|
case 52: return "jumped past memory while inflating";
|
|
case 53: return "size of zlib data too small";
|
|
|
|
/*jumped past tree while generating huffman tree, this could be when the
|
|
tree will have more leaves than symbols after generating it out of the
|
|
given lenghts. They call this an oversubscribed dynamic bit lengths tree in zlib.*/
|
|
case 55: return "jumped past tree while generating huffman tree";
|
|
|
|
case 56: return "given output image colorType or bitDepth not supported for color conversion";
|
|
case 57: return "invalid CRC encountered (checking CRC can be disabled)";
|
|
case 58: return "invalid ADLER32 encountered (checking ADLER32 can be disabled)";
|
|
case 59: return "conversion to unexisting color mode or color mode conversion not supported";
|
|
case 60: return "invalid window size given in the settings of the encoder (must be 0-32768)";
|
|
case 61: return "invalid BTYPE given in the settings of the encoder (only 0, 1 and 2 are allowed)";
|
|
/*LodePNG leaves the choice of RGB to greyscale conversion formula to the user.*/
|
|
case 62: return "conversion from RGB to greyscale not supported";
|
|
case 63: return "length of a chunk too long, max allowed for PNG is 2147483647 bytes per chunk"; /*(2^31-1)*/
|
|
/*this would result in the inability of a deflated block to ever contain an end code. It must be at least 1.*/
|
|
case 64: return "the length of the END symbol 256 in the Huffman tree is 0";
|
|
case 66: return "the length of a text chunk keyword given to the encoder is longer than the maximum of 79 bytes";
|
|
case 67: return "the length of a text chunk keyword given to the encoder is smaller than the minimum of 1 byte";
|
|
case 68: return "tried to encode a PLTE chunk with a palette that has less than 1 or more than 256 colors";
|
|
case 69: return "unknown chunk type with 'critical' flag encountered by the decoder";
|
|
case 71: return "unexisting interlace mode given to encoder (must be 0 or 1)";
|
|
case 72: return "while decoding, unexisting compression method encountering in zTXt or iTXt chunk (it must be 0)";
|
|
case 73: return "invalid tIME chunk size";
|
|
case 74: return "invalid pHYs chunk size";
|
|
/*length could be wrong, or data chopped off*/
|
|
case 75: return "no null termination char found while decoding text chunk";
|
|
case 76: return "iTXt chunk too short to contain required bytes";
|
|
case 77: return "integer overflow in buffer size";
|
|
case 78: return "failed to open file for reading"; /*file doesn't exist or couldn't be opened for reading*/
|
|
case 79: return "failed to open file for writing";
|
|
case 80: return "tried creating a tree of 0 symbols";
|
|
case 81: return "lazy matching at pos 0 is impossible";
|
|
default: ; /*nothing to do here, checks for other error values are below*/
|
|
}
|
|
|
|
if(code >= 9900 && code <= 9999) return "memory allocation failed";
|
|
|
|
return "unknown error code";
|
|
}
|
|
|
|
#endif /*LODEPNG_COMPILE_ERROR_TEXT*/
|
|
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
/* // End of PNG related code. Begin of C++ wrapper. // */
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
|
|
#ifdef __cplusplus
|
|
namespace LodePNG
|
|
{
|
|
#ifdef LODEPNG_COMPILE_DISK
|
|
void loadFile(std::vector<unsigned char>& buffer, const std::string& filename)
|
|
{
|
|
std::ifstream file(filename.c_str(), std::ios::in|std::ios::binary|std::ios::ate);
|
|
|
|
/*get filesize*/
|
|
std::streamsize size = 0;
|
|
if(file.seekg(0, std::ios::end).good()) size = file.tellg();
|
|
if(file.seekg(0, std::ios::beg).good()) size -= file.tellg();
|
|
|
|
/*read contents of the file into the vector*/
|
|
buffer.resize(size_t(size));
|
|
if(size > 0) file.read((char*)(&buffer[0]), size);
|
|
}
|
|
|
|
/*write given buffer to the file, overwriting the file, it doesn't append to it.*/
|
|
void saveFile(const std::vector<unsigned char>& buffer, const std::string& filename)
|
|
{
|
|
std::ofstream file(filename.c_str(), std::ios::out|std::ios::binary);
|
|
file.write(buffer.empty() ? 0 : (char*)&buffer[0], std::streamsize(buffer.size()));
|
|
}
|
|
#endif //LODEPNG_COMPILE_DISK
|
|
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
|
|
#ifdef LODEPNG_COMPILE_ZLIB
|
|
#ifdef LODEPNG_COMPILE_DECODER
|
|
unsigned decompress(std::vector<unsigned char>& out, const unsigned char* in, size_t insize,
|
|
const LodePNG_DecompressSettings& settings)
|
|
{
|
|
unsigned char* buffer = 0;
|
|
size_t buffersize = 0;
|
|
unsigned error = LodePNG_zlib_decompress(&buffer, &buffersize, in, insize, &settings);
|
|
if(buffer)
|
|
{
|
|
out.insert(out.end(), &buffer[0], &buffer[buffersize]);
|
|
free(buffer);
|
|
}
|
|
return error;
|
|
}
|
|
|
|
unsigned decompress(std::vector<unsigned char>& out, const std::vector<unsigned char>& in,
|
|
const LodePNG_DecompressSettings& settings)
|
|
{
|
|
return decompress(out, in.empty() ? 0 : &in[0], in.size(), settings);
|
|
}
|
|
#endif //LODEPNG_COMPILE_DECODER
|
|
|
|
#ifdef LODEPNG_COMPILE_ENCODER
|
|
unsigned compress(std::vector<unsigned char>& out, const unsigned char* in, size_t insize,
|
|
const LodePNG_CompressSettings& settings)
|
|
{
|
|
unsigned char* buffer = 0;
|
|
size_t buffersize = 0;
|
|
unsigned error = LodePNG_zlib_compress(&buffer, &buffersize, in, insize, &settings);
|
|
if(buffer)
|
|
{
|
|
out.insert(out.end(), &buffer[0], &buffer[buffersize]);
|
|
free(buffer);
|
|
}
|
|
return error;
|
|
}
|
|
|
|
unsigned compress(std::vector<unsigned char>& out, const std::vector<unsigned char>& in,
|
|
const LodePNG_CompressSettings& settings)
|
|
{
|
|
return compress(out, in.empty() ? 0 : &in[0], in.size(), settings);
|
|
}
|
|
#endif //LODEPNG_COMPILE_ENCODER
|
|
#endif //LODEPNG_COMPILE_ZLIB
|
|
|
|
#ifdef LODEPNG_COMPILE_PNG
|
|
#ifdef LODEPNG_COMPILE_DECODER
|
|
Decoder::Decoder()
|
|
{
|
|
LodePNG_Decoder_init(this);
|
|
}
|
|
|
|
Decoder::~Decoder()
|
|
{
|
|
LodePNG_Decoder_cleanup(this);
|
|
}
|
|
|
|
void Decoder::operator=(const LodePNG_Decoder& other)
|
|
{
|
|
LodePNG_Decoder_copy(this, &other);
|
|
}
|
|
|
|
bool Decoder::hasError() const
|
|
{
|
|
return error != 0;
|
|
}
|
|
unsigned Decoder::getError() const
|
|
{
|
|
return error;
|
|
}
|
|
|
|
unsigned Decoder::getWidth() const
|
|
{
|
|
return infoPng.width;
|
|
}
|
|
|
|
unsigned Decoder::getHeight() const
|
|
{
|
|
return infoPng.height;
|
|
}
|
|
|
|
unsigned Decoder::getBpp()
|
|
{
|
|
return LodePNG_InfoColor_getBpp(&infoPng.color);
|
|
}
|
|
|
|
unsigned Decoder::getChannels()
|
|
{
|
|
return LodePNG_InfoColor_getChannels(&infoPng.color);
|
|
}
|
|
|
|
unsigned Decoder::isGreyscaleType()
|
|
{
|
|
return LodePNG_InfoColor_isGreyscaleType(&infoPng.color);
|
|
}
|
|
|
|
unsigned Decoder::isAlphaType()
|
|
{
|
|
return LodePNG_InfoColor_isAlphaType(&infoPng.color);
|
|
}
|
|
|
|
void Decoder::decode(std::vector<unsigned char>& out, const unsigned char* in, size_t insize)
|
|
{
|
|
unsigned char* buffer;
|
|
size_t buffersize;
|
|
LodePNG_Decoder_decode(this, &buffer, &buffersize, in, insize);
|
|
if(buffer)
|
|
{
|
|
out.insert(out.end(), &buffer[0], &buffer[buffersize]);
|
|
free(buffer);
|
|
}
|
|
}
|
|
|
|
void Decoder::decode(std::vector<unsigned char>& out, const std::vector<unsigned char>& in)
|
|
{
|
|
decode(out, in.empty() ? 0 : &in[0], in.size());
|
|
}
|
|
|
|
void Decoder::inspect(const unsigned char* in, size_t insize)
|
|
{
|
|
LodePNG_Decoder_inspect(this, in, insize);
|
|
}
|
|
|
|
void Decoder::inspect(const std::vector<unsigned char>& in)
|
|
{
|
|
inspect(in.empty() ? 0 : &in[0], in.size());
|
|
}
|
|
|
|
const LodePNG_DecodeSettings& Decoder::getSettings() const
|
|
{
|
|
return settings;
|
|
}
|
|
|
|
LodePNG_DecodeSettings& Decoder::getSettings()
|
|
{
|
|
return settings;
|
|
}
|
|
|
|
void Decoder::setSettings(const LodePNG_DecodeSettings& settings)
|
|
{
|
|
this->settings = settings;
|
|
}
|
|
|
|
const LodePNG_InfoPng& Decoder::getInfoPng() const
|
|
{
|
|
return infoPng;
|
|
}
|
|
|
|
LodePNG_InfoPng& Decoder::getInfoPng()
|
|
{
|
|
return infoPng;
|
|
}
|
|
|
|
void Decoder::setInfoPng(const LodePNG_InfoPng& info)
|
|
{
|
|
error = LodePNG_InfoPng_copy(&this->infoPng, &info);
|
|
}
|
|
|
|
void Decoder::swapInfoPng(LodePNG_InfoPng& info)
|
|
{
|
|
LodePNG_InfoPng_swap(&this->infoPng, &info);
|
|
}
|
|
|
|
const LodePNG_InfoRaw& Decoder::getInfoRaw() const
|
|
{
|
|
return infoRaw;
|
|
}
|
|
|
|
LodePNG_InfoRaw& Decoder::getInfoRaw()
|
|
{
|
|
return infoRaw;
|
|
}
|
|
|
|
void Decoder::setInfoRaw(const LodePNG_InfoRaw& info)
|
|
{
|
|
error = LodePNG_InfoRaw_copy(&this->infoRaw, &info);
|
|
}
|
|
|
|
#endif //LODEPNG_COMPILE_DECODER
|
|
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
|
|
#ifdef LODEPNG_COMPILE_ENCODER
|
|
|
|
Encoder::Encoder()
|
|
{
|
|
LodePNG_Encoder_init(this);
|
|
}
|
|
|
|
Encoder::~Encoder()
|
|
{
|
|
LodePNG_Encoder_cleanup(this);
|
|
}
|
|
|
|
void Encoder::operator=(const LodePNG_Encoder& other)
|
|
{
|
|
LodePNG_Encoder_copy(this, &other);
|
|
}
|
|
|
|
bool Encoder::hasError() const
|
|
{
|
|
return error != 0;
|
|
}
|
|
|
|
unsigned Encoder::getError() const
|
|
{
|
|
return error;
|
|
}
|
|
|
|
void Encoder::encode(std::vector<unsigned char>& out, const unsigned char* image, unsigned w, unsigned h)
|
|
{
|
|
unsigned char* buffer;
|
|
size_t buffersize;
|
|
LodePNG_Encoder_encode(this, &buffer, &buffersize, image, w, h);
|
|
if(buffer)
|
|
{
|
|
out.insert(out.end(), &buffer[0], &buffer[buffersize]);
|
|
free(buffer);
|
|
}
|
|
}
|
|
|
|
void Encoder::encode(std::vector<unsigned char>& out, const std::vector<unsigned char>& image,
|
|
unsigned w, unsigned h)
|
|
{
|
|
encode(out, image.empty() ? 0 : &image[0], w, h);
|
|
}
|
|
|
|
void Encoder::clearPalette()
|
|
{
|
|
LodePNG_InfoColor_clearPalette(&infoPng.color);
|
|
}
|
|
|
|
void Encoder::addPalette(unsigned char r, unsigned char g, unsigned char b, unsigned char a)
|
|
{
|
|
error = LodePNG_InfoColor_addPalette(&infoPng.color, r, g, b, a);
|
|
}
|
|
|
|
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
|
|
void Encoder::clearText()
|
|
{
|
|
LodePNG_Text_clear(&infoPng.text);
|
|
}
|
|
|
|
void Encoder::addText(const std::string& key, const std::string& str)
|
|
{
|
|
error = LodePNG_Text_add(&infoPng.text, key.c_str(), str.c_str());
|
|
}
|
|
|
|
void Encoder::clearIText()
|
|
{
|
|
LodePNG_IText_clear(&infoPng.itext);
|
|
}
|
|
|
|
void Encoder::addIText(const std::string& key, const std::string& langtag,
|
|
const std::string& transkey, const std::string& str)
|
|
{
|
|
error = LodePNG_IText_add(&infoPng.itext, key.c_str(), langtag.c_str(), transkey.c_str(), str.c_str());
|
|
}
|
|
#endif //LODEPNG_COMPILE_ANCILLARY_CHUNKS
|
|
|
|
const LodePNG_EncodeSettings& Encoder::getSettings() const
|
|
{
|
|
return settings;
|
|
}
|
|
|
|
LodePNG_EncodeSettings& Encoder::getSettings()
|
|
{
|
|
return settings;
|
|
}
|
|
|
|
void Encoder::setSettings(const LodePNG_EncodeSettings& settings)
|
|
{
|
|
this->settings = settings;
|
|
}
|
|
|
|
const LodePNG_InfoPng& Encoder::getInfoPng() const
|
|
{
|
|
return infoPng;
|
|
}
|
|
|
|
LodePNG_InfoPng& Encoder::getInfoPng()
|
|
{
|
|
return infoPng;
|
|
}
|
|
|
|
void Encoder::setInfoPng(const LodePNG_InfoPng& info)
|
|
{
|
|
error = LodePNG_InfoPng_copy(&this->infoPng, &info);
|
|
}
|
|
|
|
void Encoder::swapInfoPng(LodePNG_InfoPng& info)
|
|
{
|
|
LodePNG_InfoPng_swap(&this->infoPng, &info);
|
|
}
|
|
|
|
const LodePNG_InfoRaw& Encoder::getInfoRaw() const
|
|
{
|
|
return infoRaw;
|
|
}
|
|
|
|
LodePNG_InfoRaw& Encoder::getInfoRaw()
|
|
{
|
|
return infoRaw;
|
|
}
|
|
|
|
void Encoder::setInfoRaw(const LodePNG_InfoRaw& info)
|
|
{
|
|
error = LodePNG_InfoRaw_copy(&this->infoRaw, &info);
|
|
}
|
|
#endif //LODEPNG_COMPILE_ENCODER
|
|
|
|
/* ////////////////////////////////////////////////////////////////////////// */
|
|
|
|
#ifdef LODEPNG_COMPILE_DECODER
|
|
|
|
unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h, const unsigned char* in,
|
|
size_t insize, unsigned colorType, unsigned bitDepth)
|
|
{
|
|
Decoder decoder;
|
|
decoder.getInfoRaw().color.colorType = colorType;
|
|
decoder.getInfoRaw().color.bitDepth = bitDepth;
|
|
decoder.decode(out, in, insize);
|
|
w = decoder.getWidth();
|
|
h = decoder.getHeight();
|
|
return decoder.getError();
|
|
}
|
|
|
|
unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h,
|
|
const std::vector<unsigned char>& in, unsigned colorType, unsigned bitDepth)
|
|
{
|
|
return decode(out, w, h, in.empty() ? 0 : &in[0], (unsigned)in.size(), colorType, bitDepth);
|
|
}
|
|
|
|
#ifdef LODEPNG_COMPILE_DISK
|
|
unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h, const std::string& filename,
|
|
unsigned colorType, unsigned bitDepth)
|
|
{
|
|
std::vector<unsigned char> buffer;
|
|
loadFile(buffer, filename);
|
|
return decode(out, w, h, buffer, colorType, bitDepth);
|
|
}
|
|
#endif //LODEPNG_COMPILE_DECODER
|
|
#endif //LODEPNG_COMPILE_DISK
|
|
|
|
#ifdef LODEPNG_COMPILE_ENCODER
|
|
|
|
unsigned encode(std::vector<unsigned char>& out, const unsigned char* in, unsigned w, unsigned h,
|
|
unsigned colorType, unsigned bitDepth)
|
|
{
|
|
Encoder encoder;
|
|
encoder.getInfoRaw().color.colorType = colorType;
|
|
encoder.getInfoRaw().color.bitDepth = bitDepth;
|
|
encoder.getInfoPng().color.colorType = colorType;
|
|
encoder.getInfoPng().color.bitDepth = bitDepth;
|
|
encoder.encode(out, in, w, h);
|
|
return encoder.getError();
|
|
}
|
|
|
|
unsigned encode(std::vector<unsigned char>& out, const std::vector<unsigned char>& in, unsigned w, unsigned h,
|
|
unsigned colorType, unsigned bitDepth)
|
|
{
|
|
return encode(out, in.empty() ? 0 : &in[0], w, h, colorType, bitDepth);
|
|
}
|
|
|
|
#ifdef LODEPNG_COMPILE_DISK
|
|
unsigned encode(const std::string& filename, const unsigned char* in, unsigned w, unsigned h,
|
|
unsigned colorType, unsigned bitDepth)
|
|
{
|
|
std::vector<unsigned char> buffer;
|
|
Encoder encoder;
|
|
encoder.getInfoRaw().color.colorType = colorType;
|
|
encoder.getInfoRaw().color.bitDepth = bitDepth;
|
|
encoder.encode(buffer, in, w, h);
|
|
if(!encoder.hasError()) saveFile(buffer, filename);
|
|
return encoder.getError();
|
|
}
|
|
|
|
unsigned encode(const std::string& filename, const std::vector<unsigned char>& in, unsigned w, unsigned h,
|
|
unsigned colorType, unsigned bitDepth)
|
|
{
|
|
return encode(filename, in.empty() ? 0 : &in[0], w, h, colorType, bitDepth);
|
|
}
|
|
#endif //LODEPNG_COMPILE_DISK
|
|
#endif //LODEPNG_COMPILE_ENCODER
|
|
#endif //LODEPNG_COMPILE_PNG
|
|
} //namespace LodePNG
|
|
#endif /*__cplusplus C++ RAII wrapper*/
|