adding lodepng to github

1 files changed, 6104 insertions, 0 deletions

diff --git a/lodepng.cpp b/lodepng.cpp
new file mode 100644
index 0000000..2be3fbe
--- /dev/null
+++ b/lodepng.cpp
@@ -0,0 +1,6104 @@
+/*
+LodePNG version 20140823
+
+Copyright (c) 2005-2014 Lode Vandevenne
+
+This software is provided 'as-is', without any express or implied
+warranty. In no event will the authors be held liable for any damages
+arising from the use of this software.
+
+Permission is granted to anyone to use this software for any purpose,
+including commercial applications, and to alter it and redistribute it
+freely, subject to the following restrictions:
+
+    1. The origin of this software must not be misrepresented; you must not
+    claim that you wrote the original software. If you use this software
+    in a product, an acknowledgment in the product documentation would be
+    appreciated but is not required.
+
+    2. Altered source versions must be plainly marked as such, and must not be
+    misrepresented as being the original software.
+
+    3. This notice may not be removed or altered from any source
+    distribution.
+*/
+
+/*
+The manual and changelog are in the header file "lodepng.h"
+Rename this file to lodepng.cpp to use it for C++, or to lodepng.c to use it for C.
+*/
+
+#include "lodepng.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#ifdef LODEPNG_COMPILE_CPP
+#include <fstream>
+#endif /*LODEPNG_COMPILE_CPP*/
+
+#define VERSION_STRING "20140823"
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1310) /*Visual Studio: A few warning types are not desired here.*/
+#pragma warning( disable : 4244 ) /*implicit conversions: not warned by gcc -Wall -Wextra and requires too much casts*/
+#pragma warning( disable : 4996 ) /*VS does not like fopen, but fopen_s is not standard C so unusable here*/
+#endif /*_MSC_VER */
+
+/*
+This source file is built up in the following large parts. The code sections
+with the "LODEPNG_COMPILE_" #defines divide this up further in an intermixed way.
+-Tools for C and common code for PNG and Zlib
+-C Code for Zlib (huffman, deflate, ...)
+-C Code for PNG (file format chunks, adam7, PNG filters, color conversions, ...)
+-The C++ wrapper around all of the above
+*/
+
+/*The malloc, realloc and free functions defined here with "lodepng_" in front
+of the name, so that you can easily change them to others related to your
+platform if needed. Everything else in the code calls these. Pass
+-DLODEPNG_NO_COMPILE_ALLOCATORS to the compiler, or comment out
+#define LODEPNG_COMPILE_ALLOCATORS in the header, to disable the ones here and
+define them in your own project's source files without needing to change
+lodepng source code. Don't forget to remove "static" if you copypaste them
+from here.*/
+
+#ifdef LODEPNG_COMPILE_ALLOCATORS
+static void* lodepng_malloc(size_t size)
+{
+  return malloc(size);
+}
+
+static void* lodepng_realloc(void* ptr, size_t new_size)
+{
+  return realloc(ptr, new_size);
+}
+
+static void lodepng_free(void* ptr)
+{
+  free(ptr);
+}
+#else /*LODEPNG_COMPILE_ALLOCATORS*/
+void* lodepng_malloc(size_t size);
+void* lodepng_realloc(void* ptr, size_t new_size);
+void lodepng_free(void* ptr);
+#endif /*LODEPNG_COMPILE_ALLOCATORS*/
+
+/* ////////////////////////////////////////////////////////////////////////// */
+/* ////////////////////////////////////////////////////////////////////////// */
+/* // Tools for C, and common code for PNG and Zlib.                       // */
+/* ////////////////////////////////////////////////////////////////////////// */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+/*
+Often in case of an error a value is assigned to a variable and then it breaks
+out of a loop (to go to the cleanup phase of a function). This macro does that.
+It makes the error handling code shorter and more readable.
+
+Example: if(!uivector_resizev(&frequencies_ll, 286, 0)) ERROR_BREAK(83);
+*/
+#define CERROR_BREAK(errorvar, code)\
+{\
+  errorvar = code;\
+  break;\
+}
+
+/*version of CERROR_BREAK that assumes the common case where the error variable is named "error"*/
+#define ERROR_BREAK(code) CERROR_BREAK(error, code)
+
+/*Set error var to the error code, and return it.*/
+#define CERROR_RETURN_ERROR(errorvar, code)\
+{\
+  errorvar = code;\
+  return code;\
+}
+
+/*Try the code, if it returns error, also return the error.*/
+#define CERROR_TRY_RETURN(call)\
+{\
+  unsigned error = call;\
+  if(error) return error;\
+}
+
+/*
+About uivector, ucvector and string:
+-All of them wrap dynamic arrays or text strings in a similar way.
+-LodePNG was originally written in C++. The vectors replace the std::vectors that were used in the C++ version.
+-The string tools are made to avoid problems with compilers that declare things like strncat as deprecated.
+-They're not used in the interface, only internally in this file as static functions.
+-As with many other structs in this file, the init and cleanup functions serve as ctor and dtor.
+*/
+
+#ifdef LODEPNG_COMPILE_ZLIB
+/*dynamic vector of unsigned ints*/
+typedef struct uivector
+{
+  unsigned* data;
+  size_t size; /*size in number of unsigned longs*/
+  size_t allocsize; /*allocated size in bytes*/
+} uivector;
+
+static void uivector_cleanup(void* p)
+{
+  ((uivector*)p)->size = ((uivector*)p)->allocsize = 0;
+  lodepng_free(((uivector*)p)->data);
+  ((uivector*)p)->data = NULL;
+}
+
+/*returns 1 if success, 0 if failure ==> nothing done*/
+static unsigned uivector_reserve(uivector* p, size_t allocsize)
+{
+  if(allocsize > p->allocsize)
+  {
+    size_t newsize = (allocsize > p->allocsize * 2) ? allocsize : (allocsize * 3 / 2);
+    void* data = lodepng_realloc(p->data, newsize);
+    if(data)
+    {
+      p->allocsize = newsize;
+      p->data = (unsigned*)data;
+    }
+    else return 0; /*error: not enough memory*/
+  }
+  return 1;
+}
+
+/*returns 1 if success, 0 if failure ==> nothing done*/
+static unsigned uivector_resize(uivector* p, size_t size)
+{
+  if(!uivector_reserve(p, size * sizeof(unsigned))) return 0;
+  p->size = size;
+  return 1; /*success*/
+}
+
+/*resize and give all new elements the value*/
+static unsigned uivector_resizev(uivector* p, size_t size, unsigned value)
+{
+  size_t oldsize = p->size, i;
+  if(!uivector_resize(p, size)) return 0;
+  for(i = oldsize; i < size; i++) p->data[i] = value;
+  return 1;
+}
+
+static void uivector_init(uivector* p)
+{
+  p->data = NULL;
+  p->size = p->allocsize = 0;
+}
+
+#ifdef LODEPNG_COMPILE_ENCODER
+/*returns 1 if success, 0 if failure ==> nothing done*/
+static unsigned uivector_push_back(uivector* p, unsigned c)
+{
+  if(!uivector_resize(p, p->size + 1)) return 0;
+  p->data[p->size - 1] = c;
+  return 1;
+}
+
+/*copy q to p, returns 1 if success, 0 if failure ==> nothing done*/
+static unsigned uivector_copy(uivector* p, const uivector* q)
+{
+  size_t i;
+  if(!uivector_resize(p, q->size)) return 0;
+  for(i = 0; i < q->size; i++) p->data[i] = q->data[i];
+  return 1;
+}
+#endif /*LODEPNG_COMPILE_ENCODER*/
+#endif /*LODEPNG_COMPILE_ZLIB*/
+
+/* /////////////////////////////////////////////////////////////////////////// */
+
+/*dynamic vector of unsigned chars*/
+typedef struct ucvector
+{
+  unsigned char* data;
+  size_t size; /*used size*/
+  size_t allocsize; /*allocated size*/
+} ucvector;
+
+/*returns 1 if success, 0 if failure ==> nothing done*/
+static unsigned ucvector_reserve(ucvector* p, size_t allocsize)
+{
+  if(allocsize > p->allocsize)
+  {
+    size_t newsize = (allocsize > p->allocsize * 2) ? allocsize : (allocsize * 3 / 2);
+    void* data = lodepng_realloc(p->data, newsize);
+    if(data)
+    {
+      p->allocsize = newsize;
+      p->data = (unsigned char*)data;
+    }
+    else return 0; /*error: not enough memory*/
+  }
+  return 1;
+}
+
+/*returns 1 if success, 0 if failure ==> nothing done*/
+static unsigned ucvector_resize(ucvector* p, size_t size)
+{
+  if(!ucvector_reserve(p, size * sizeof(unsigned char))) return 0;
+  p->size = size;
+  return 1; /*success*/
+}
+
+#ifdef LODEPNG_COMPILE_PNG
+
+static void ucvector_cleanup(void* p)
+{
+  ((ucvector*)p)->size = ((ucvector*)p)->allocsize = 0;
+  lodepng_free(((ucvector*)p)->data);
+  ((ucvector*)p)->data = NULL;
+}
+
+static void ucvector_init(ucvector* p)
+{
+  p->data = NULL;
+  p->size = p->allocsize = 0;
+}
+
+#ifdef LODEPNG_COMPILE_DECODER
+/*resize and give all new elements the value*/
+static unsigned ucvector_resizev(ucvector* p, size_t size, unsigned char value)
+{
+  size_t oldsize = p->size, i;
+  if(!ucvector_resize(p, size)) return 0;
+  for(i = oldsize; i < size; i++) p->data[i] = value;
+  return 1;
+}
+#endif /*LODEPNG_COMPILE_DECODER*/
+#endif /*LODEPNG_COMPILE_PNG*/
+
+#ifdef LODEPNG_COMPILE_ZLIB
+/*you can both convert from vector to buffer&size and vica versa. If you use
+init_buffer to take over a buffer and size, it is not needed to use cleanup*/
+static void ucvector_init_buffer(ucvector* p, unsigned char* buffer, size_t size)
+{
+  p->data = buffer;
+  p->allocsize = p->size = size;
+}
+#endif /*LODEPNG_COMPILE_ZLIB*/
+
+#if (defined(LODEPNG_COMPILE_PNG) && defined(LODEPNG_COMPILE_ANCILLARY_CHUNKS)) || defined(LODEPNG_COMPILE_ENCODER)
+/*returns 1 if success, 0 if failure ==> nothing done*/
+static unsigned ucvector_push_back(ucvector* p, unsigned char c)
+{
+  if(!ucvector_resize(p, p->size + 1)) return 0;
+  p->data[p->size - 1] = c;
+  return 1;
+}
+#endif /*defined(LODEPNG_COMPILE_PNG) || defined(LODEPNG_COMPILE_ENCODER)*/
+
+
+/* ////////////////////////////////////////////////////////////////////////// */
+
+#ifdef LODEPNG_COMPILE_PNG
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+/*returns 1 if success, 0 if failure ==> nothing done*/
+static unsigned string_resize(char** out, size_t size)
+{
+  char* data = (char*)lodepng_realloc(*out, size + 1);
+  if(data)
+  {
+    data[size] = 0; /*null termination char*/
+    *out = data;
+  }
+  return data != 0;
+}
+
+/*init a {char*, size_t} pair for use as string*/
+static void string_init(char** out)
+{
+  *out = NULL;
+  string_resize(out, 0);
+}
+
+/*free the above pair again*/
+static void string_cleanup(char** out)
+{
+  lodepng_free(*out);
+  *out = NULL;
+}
+
+static void string_set(char** out, const char* in)
+{
+  size_t insize = strlen(in), i = 0;
+  if(string_resize(out, insize))
+  {
+    for(i = 0; i < insize; i++)
+    {
+      (*out)[i] = in[i];
+    }
+  }
+}
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+#endif /*LODEPNG_COMPILE_PNG*/
+
+/* ////////////////////////////////////////////////////////////////////////// */
+
+unsigned lodepng_read32bitInt(const unsigned char* buffer)
+{
+  return (unsigned)((buffer[0] << 24) | (buffer[1] << 16) | (buffer[2] << 8) | buffer[3]);
+}
+
+#if defined(LODEPNG_COMPILE_PNG) || defined(LODEPNG_COMPILE_ENCODER)
+/*buffer must have at least 4 allocated bytes available*/
+static void lodepng_set32bitInt(unsigned char* buffer, unsigned value)
+{
+  buffer[0] = (unsigned char)((value >> 24) & 0xff);
+  buffer[1] = (unsigned char)((value >> 16) & 0xff);
+  buffer[2] = (unsigned char)((value >>  8) & 0xff);
+  buffer[3] = (unsigned char)((value      ) & 0xff);
+}
+#endif /*defined(LODEPNG_COMPILE_PNG) || defined(LODEPNG_COMPILE_ENCODER)*/
+
+#ifdef LODEPNG_COMPILE_ENCODER
+static void lodepng_add32bitInt(ucvector* buffer, unsigned value)
+{
+  ucvector_resize(buffer, buffer->size + 4); /*todo: give error if resize failed*/
+  lodepng_set32bitInt(&buffer->data[buffer->size - 4], value);
+}
+#endif /*LODEPNG_COMPILE_ENCODER*/
+
+/* ////////////////////////////////////////////////////////////////////////// */
+/* / File IO                                                                / */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+#ifdef LODEPNG_COMPILE_DISK
+
+unsigned lodepng_load_file(unsigned char** out, size_t* outsize, const char* filename)
+{
+  FILE* file;
+  long size;
+
+  /*provide some proper output values if error will happen*/
+  *out = 0;
+  *outsize = 0;
+
+  file = fopen(filename, "rb");
+  if(!file) return 78;
+
+  /*get filesize:*/
+  fseek(file , 0 , SEEK_END);
+  size = ftell(file);
+  rewind(file);
+
+  /*read contents of the file into the vector*/
+  *outsize = 0;
+  *out = (unsigned char*)lodepng_malloc((size_t)size);
+  if(size && (*out)) (*outsize) = fread(*out, 1, (size_t)size, file);
+
+  fclose(file);
+  if(!(*out) && size) return 83; /*the above malloc failed*/
+  return 0;
+}
+
+/*write given buffer to the file, overwriting the file, it doesn't append to it.*/
+unsigned lodepng_save_file(const unsigned char* buffer, size_t buffersize, const char* filename)
+{
+  FILE* file;
+  file = fopen(filename, "wb" );
+  if(!file) return 79;
+  fwrite((char*)buffer , 1 , buffersize, file);
+  fclose(file);
+  return 0;
+}
+
+#endif /*LODEPNG_COMPILE_DISK*/
+
+/* ////////////////////////////////////////////////////////////////////////// */
+/* ////////////////////////////////////////////////////////////////////////// */
+/* // End of common code and tools. Begin of Zlib related code.            // */
+/* ////////////////////////////////////////////////////////////////////////// */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+#ifdef LODEPNG_COMPILE_ZLIB
+#ifdef LODEPNG_COMPILE_ENCODER
+/*TODO: this ignores potential out of memory errors*/
+#define addBitToStream(/*size_t**/ bitpointer, /*ucvector**/ bitstream, /*unsigned char*/ bit)\
+{\
+  /*add a new byte at the end*/\
+  if(((*bitpointer) & 7) == 0) ucvector_push_back(bitstream, (unsigned char)0);\
+  /*earlier bit of huffman code is in a lesser significant bit of an earlier byte*/\
+  (bitstream->data[bitstream->size - 1]) |= (bit << ((*bitpointer) & 0x7));\
+  (*bitpointer)++;\
+}
+
+static void addBitsToStream(size_t* bitpointer, ucvector* bitstream, unsigned value, size_t nbits)
+{
+  size_t i;
+  for(i = 0; i < nbits; i++) addBitToStream(bitpointer, bitstream, (unsigned char)((value >> i) & 1));
+}
+
+static void addBitsToStreamReversed(size_t* bitpointer, ucvector* bitstream, unsigned value, size_t nbits)
+{
+  size_t i;
+  for(i = 0; i < nbits; i++) addBitToStream(bitpointer, bitstream, (unsigned char)((value >> (nbits - 1 - i)) & 1));
+}
+#endif /*LODEPNG_COMPILE_ENCODER*/
+
+#ifdef LODEPNG_COMPILE_DECODER
+
+#define READBIT(bitpointer, bitstream) ((bitstream[bitpointer >> 3] >> (bitpointer & 0x7)) & (unsigned char)1)
+
+static unsigned char readBitFromStream(size_t* bitpointer, const unsigned char* bitstream)
+{
+  unsigned char result = (unsigned char)(READBIT(*bitpointer, bitstream));
+  (*bitpointer)++;
+  return result;
+}
+
+static unsigned readBitsFromStream(size_t* bitpointer, const unsigned char* bitstream, size_t nbits)
+{
+  unsigned result = 0, i;
+  for(i = 0; i < nbits; i++)
+  {
+    result += ((unsigned)READBIT(*bitpointer, bitstream)) << i;
+    (*bitpointer)++;
+  }
+  return result;
+}
+#endif /*LODEPNG_COMPILE_DECODER*/
+
+/* ////////////////////////////////////////////////////////////////////////// */
+/* / Deflate - Huffman                                                      / */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+#define FIRST_LENGTH_CODE_INDEX 257
+#define LAST_LENGTH_CODE_INDEX 285
+/*256 literals, the end code, some length codes, and 2 unused codes*/
+#define NUM_DEFLATE_CODE_SYMBOLS 288
+/*the distance codes have their own symbols, 30 used, 2 unused*/
+#define NUM_DISTANCE_SYMBOLS 32
+/*the code length codes. 0-15: code lengths, 16: copy previous 3-6 times, 17: 3-10 zeros, 18: 11-138 zeros*/
+#define NUM_CODE_LENGTH_CODES 19
+
+/*the base lengths represented by codes 257-285*/
+static const unsigned LENGTHBASE[29]
+  = {3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31, 35, 43, 51, 59,
+     67, 83, 99, 115, 131, 163, 195, 227, 258};
+
+/*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
+{
+  unsigned* tree2d;
+  unsigned* tree1d;
+  unsigned* 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++*/
+/*
+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)
+{
+  tree->tree2d = 0;
+  tree->tree1d = 0;
+  tree->lengths = 0;
+}
+
+static void HuffmanTree_cleanup(HuffmanTree* tree)
+{
+  lodepng_free(tree->tree2d);
+  lodepng_free(tree->tree1d);
+  lodepng_free(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;
+
+  tree->tree2d = (unsigned*)lodepng_malloc(tree->numcodes * 2 * sizeof(unsigned));
+  if(!tree->tree2d) return 83; /*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[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[n]; i++) /*the bits for this code*/
+    {
+      unsigned char bit = (unsigned char)((tree->tree1d[n] >> (tree->lengths[n] - i - 1)) & 1);
+      if(treepos > tree->numcodes - 2) return 55; /*oversubscribed, see comment in lodepng_error_text*/
+      if(tree->tree2d[2 * treepos + bit] == 32767) /*not yet filled in*/
+      {
+        if(i + 1 == tree->lengths[n]) /*last bit*/
+        {
+          tree->tree2d[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[2 * treepos + bit] = nodefilled + tree->numcodes;
+          treepos = nodefilled;
+        }
+      }
+      else treepos = tree->tree2d[2 * treepos + bit] - tree->numcodes;
+    }
+  }
+
+  for(n = 0; n < tree->numcodes * 2; n++)
+  {
+    if(tree->tree2d[n] == 32767) tree->tree2d[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);
+
+  tree->tree1d = (unsigned*)lodepng_malloc(tree->numcodes * sizeof(unsigned));
+  if(!tree->tree1d) error = 83; /*alloc fail*/
+
+  if(!uivector_resizev(&blcount, tree->maxbitlen + 1, 0)
+  || !uivector_resizev(&nextcode, tree->maxbitlen + 1, 0))
+    error = 83; /*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[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[n] != 0) tree->tree1d[n] = nextcode.data[tree->lengths[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;
+  tree->lengths = (unsigned*)lodepng_malloc(numcodes * sizeof(unsigned));
+  if(!tree->lengths) return 83; /*alloc fail*/
+  for(i = 0; i < numcodes; i++) tree->lengths[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 add_coins(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;
+}
+
+static void init_coins(Coin* coins, size_t num)
+{
+  size_t i;
+  for(i = 0; i < num; i++) coin_init(&coins[i]);
+}
+
+static void cleanup_coins(Coin* coins, size_t num)
+{
+  size_t i;
+  for(i = 0; i < num; i++) coin_cleanup(&coins[i]);
+}
+
+static int coin_compare(const void* a, const void* b) {
+  float wa = ((const Coin*)a)->weight;
+  float wb = ((const Coin*)b)->weight;
+  return wa > wb ? 1 : wa < wb ? -1 : 0;
+}
+
+static unsigned append_symbol_coins(Coin* coins, const unsigned* frequencies, unsigned numcodes, size_t sum)
+{
+  unsigned i;
+  unsigned j = 0; /*index of present symbols*/
+  for(i = 0; i < numcodes; i++)
+  {
+    if(frequencies[i] != 0) /*only include symbols that are present*/
+    {
+      coins[j].weight = frequencies[i] / (float)sum;
+      uivector_push_back(&coins[j].symbols, i);
+      j++;
+    }
+  }
+  return 0;
+}
+
+unsigned lodepng_huffman_code_lengths(unsigned* lengths, const unsigned* frequencies,
+                                      size_t numcodes, unsigned maxbitlen)
+{
+  unsigned i, j;
+  size_t sum = 0, numpresent = 0;
+  unsigned error = 0;
+  Coin* coins; /*the coins of the currently calculated row*/
+  Coin* prev_row; /*the previous row of coins*/
+  size_t numcoins;
+  size_t coinmem;
+
+  if(numcodes == 0) return 80; /*error: a tree of 0 symbols is not supposed to be made*/
+
+  for(i = 0; i < numcodes; i++)
+  {
+    if(frequencies[i] > 0)
+    {
+      numpresent++;
+      sum += frequencies[i];
+    }
+  }
+
+  for(i = 0; i < numcodes; i++) lengths[i] = 0;
+
+  /*ensure at least two present symbols. There should be at least one symbol
+  according to RFC 1951 section 3.2.7. To decoders incorrectly require two. To
+  make these work as well ensure there are at least two symbols. The
+  Package-Merge code below also doesn't work correctly if there's only one
+  symbol, it'd give it the theoritical 0 bits but in practice zlib wants 1 bit*/
+  if(numpresent == 0)
+  {
+    lengths[0] = lengths[1] = 1; /*note that for RFC 1951 section 3.2.7, only lengths[0] = 1 is needed*/
+  }
+  else if(numpresent == 1)
+  {
+    for(i = 0; i < numcodes; i++)
+    {
+      if(frequencies[i])
+      {
+        lengths[i] = 1;
+        lengths[i == 0 ? 1 : 0] = 1;
+        break;
+      }
+    }
+  }
+  else
+  {
+    /*Package-Merge algorithm represented by coin collector's problem
+    For every symbol, maxbitlen coins will be created*/
+
+    coinmem = numpresent * 2; /*max amount of coins needed with the current algo*/
+    coins = (Coin*)lodepng_malloc(sizeof(Coin) * coinmem);
+    prev_row = (Coin*)lodepng_malloc(sizeof(Coin) * coinmem);
+    if(!coins || !prev_row)
+    {
+      lodepng_free(coins);
+      lodepng_free(prev_row);
+      return 83; /*alloc fail*/
+    }
+    init_coins(coins, coinmem);
+    init_coins(prev_row, coinmem);
+
+    /*first row, lowest denominator*/
+    error = append_symbol_coins(coins, frequencies, numcodes, sum);
+    numcoins = numpresent;
+    qsort(coins, numcoins, sizeof(Coin), coin_compare);
+    if(!error)
+    {
+      unsigned numprev = 0;
+      for(j = 1; j <= maxbitlen && !error; j++) /*each of the remaining rows*/
+      {
+        unsigned tempnum;
+        Coin* tempcoins;
+        /*swap prev_row and coins, and their amounts*/
+        tempcoins = prev_row; prev_row = coins; coins = tempcoins;
+        tempnum = numprev; numprev = numcoins; numcoins = tempnum;
+
+        cleanup_coins(coins, numcoins);
+        init_coins(coins, numcoins);
+
+        numcoins = 0;
+
+        /*fill in the merged coins of the previous row*/
+        for(i = 0; i + 1 < numprev; i += 2)
+        {
+          /*merge prev_row[i] and prev_row[i + 1] into new coin*/
+          Coin* coin = &coins[numcoins++];
+          coin_copy(coin, &prev_row[i]);
+          add_coins(coin, &prev_row[i + 1]);
+        }
+        /*fill in all the original symbols again*/
+        if(j < maxbitlen)
+        {
+          error = append_symbol_coins(coins + numcoins, frequencies, numcodes, sum);
+          numcoins += numpresent;
+        }
+        qsort(coins, numcoins, sizeof(Coin), coin_compare);
+      }
+    }
+
+    if(!error)
+    {
+      /*calculate the lenghts of each symbol, as the amount of times a coin of each symbol is used*/
+      for(i = 0; i < numpresent - 1; i++)
+      {
+        Coin* coin = &coins[i];
+        for(j = 0; j < coin->symbols.size; j++) lengths[coin->symbols.data[j]]++;
+      }
+    }
+
+    cleanup_coins(coins, coinmem);
+    lodepng_free(coins);
+    cleanup_coins(prev_row, coinmem);
+    lodepng_free(prev_row);
+  }
+
+  return error;
+}
+
+/*Create the Huffman tree given the symbol frequencies*/
+static unsigned HuffmanTree_makeFromFrequencies(HuffmanTree* tree, const unsigned* frequencies,
+                                                size_t mincodes, size_t numcodes, unsigned maxbitlen)
+{
+  unsigned error = 0;
+  while(!frequencies[numcodes - 1] && numcodes > mincodes) numcodes--; /*trim zeroes*/
+  tree->maxbitlen = maxbitlen;
+  tree->numcodes = (unsigned)numcodes; /*number of symbols*/
+  tree->lengths = (unsigned*)lodepng_realloc(tree->lengths, numcodes * sizeof(unsigned));
+  if(!tree->lengths) return 83; /*alloc fail*/
+  /*initialize all lengths to 0*/
+  memset(tree->lengths, 0, numcodes * sizeof(unsigned));
+
+  error = lodepng_huffman_code_lengths(tree->lengths, frequencies, numcodes, maxbitlen);
+  if(!error) error = HuffmanTree_makeFromLengths2(tree);
+  return error;
+}
+
+static unsigned HuffmanTree_getCode(const HuffmanTree* tree, unsigned index)
+{
+  return tree->tree1d[index];
+}
+
+static unsigned HuffmanTree_getLength(const HuffmanTree* tree, unsigned index)
+{
+  return tree->lengths[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;
+  unsigned* bitlen = (unsigned*)lodepng_malloc(NUM_DEFLATE_CODE_SYMBOLS * sizeof(unsigned));
+  if(!bitlen) return 83; /*alloc fail*/
+
+  /*288 possible codes: 0-255=literals, 256=endcode, 257-285=lengthcodes, 286-287=unused*/
+  for(i =   0; i <= 143; i++) bitlen[i] = 8;
+  for(i = 144; i <= 255; i++) bitlen[i] = 9;
+  for(i = 256; i <= 279; i++) bitlen[i] = 7;
+  for(i = 280; i <= 287; i++) bitlen[i] = 8;
+
+  error = HuffmanTree_makeFromLengths(tree, bitlen, NUM_DEFLATE_CODE_SYMBOLS, 15);
+
+  lodepng_free(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;
+  unsigned* bitlen = (unsigned*)lodepng_malloc(NUM_DISTANCE_SYMBOLS * sizeof(unsigned));
+  if(!bitlen) return 83; /*alloc fail*/
+
+  /*there are 32 distance codes, but 30-31 are unused*/
+  for(i = 0; i < NUM_DISTANCE_SYMBOLS; i++) bitlen[i] = 5;
+  error = HuffmanTree_makeFromLengths(tree, bitlen, NUM_DISTANCE_SYMBOLS, 15);
+
+  lodepng_free(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[(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)
+{
+  /*TODO: check for out of memory errors*/
+  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*/
+  unsigned* bitlen_ll = 0; /*lit,len code lengths*/
+  unsigned* bitlen_d = 0; /*dist code lengths*/
+  /*code length code lengths ("clcl"), the bit lengths of the huffman tree used to compress bitlen_ll and bitlen_d*/
+  unsigned* bitlen_cl = 0;
+  HuffmanTree tree_cl; /*the code tree for code length codes (the huffman tree for compressed huffman trees)*/
+
+  if((*bp) >> 3 >= inlength - 2) return 49; /*error: 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);
+
+  while(!error)
+  {
+    /*read the code length codes out of 3 * (amount of code length codes) bits*/
+
+    bitlen_cl = (unsigned*)lodepng_malloc(NUM_CODE_LENGTH_CODES * sizeof(unsigned));
+    if(!bitlen_cl) ERROR_BREAK(83 /*alloc fail*/);
+
+    for(i = 0; i < NUM_CODE_LENGTH_CODES; i++)
+    {
+      if(i < HCLEN) bitlen_cl[CLCL_ORDER[i]] = readBitsFromStream(bp, in, 3);
+      else bitlen_cl[CLCL_ORDER[i]] = 0; /*if not, it must stay 0*/
+    }
+
+    error = HuffmanTree_makeFromLengths(&tree_cl, bitlen_cl, NUM_CODE_LENGTH_CODES, 7);
+    if(error) break;
+
+    /*now we can use this tree to read the lengths for the tree that this function will return*/
+    bitlen_ll = (unsigned*)lodepng_malloc(NUM_DEFLATE_CODE_SYMBOLS * sizeof(unsigned));
+    bitlen_d = (unsigned*)lodepng_malloc(NUM_DISTANCE_SYMBOLS * sizeof(unsigned));
+    if(!bitlen_ll || !bitlen_d) ERROR_BREAK(83 /*alloc fail*/);
+    for(i = 0; i < NUM_DEFLATE_CODE_SYMBOLS; i++) bitlen_ll[i] = 0;
+    for(i = 0; i < NUM_DISTANCE_SYMBOLS; i++) bitlen_d[i] = 0;
+
+    /*i is the current symbol we're reading in the part that contains the code lengths of lit/len and dist codes*/
+    i = 0;
+    while(i < HLIT + HDIST)
+    {
+      unsigned code = huffmanDecodeSymbol(in, bp, &tree_cl, inbitlength);
+      if(code <= 15) /*a length code*/
+      {
+        if(i < HLIT) bitlen_ll[i] = code;
+        else bitlen_d[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 >= inbitlength) ERROR_BREAK(50); /*error, bit pointer jumps past memory*/
+        if (i == 0) ERROR_BREAK(54); /*can't repeat previous if i is 0*/
+
+        replength += readBitsFromStream(bp, in, 2);
+
+        if(i < HLIT + 1) value = bitlen_ll[i - 1];
+        else value = bitlen_d[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[i] = value;
+          else bitlen_d[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 >= inbitlength) 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[i] = 0;
+          else bitlen_d[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 >= inbitlength) 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[i] = 0;
+          else bitlen_d[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) > inbitlength ? 10 : 11;
+        }
+        else error = 16; /*unexisting code, this can never happen*/
+        break;
+      }
+    }
+    if(error) break;
+
+    if(bitlen_ll[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, NUM_DEFLATE_CODE_SYMBOLS, 15);
+    if(error) break;
+    error = HuffmanTree_makeFromLengths(tree_d, bitlen_d, NUM_DISTANCE_SYMBOLS, 15);
+
+    break; /*end of error-while*/
+  }
+
+  lodepng_free(bitlen_cl);
+  lodepng_free(bitlen_ll);
+  lodepng_free(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);
+
+  while(!error) /*decode all symbols until end reached, breaks at end code*/
+  {
+    /*code_ll is literal, length or end code*/
+    unsigned code_ll = huffmanDecodeSymbol(in, bp, &tree_ll, inbitlength);
+    if(code_ll <= 255) /*literal symbol*/
+    {
+      /*ucvector_push_back would do the same, but for some reason the two lines below run 10% faster*/
+      if(!ucvector_resize(out, (*pos) + 1)) ERROR_BREAK(83 /*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 >= inbitlength) 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 >= inbitlength) 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);
+      if(distance > start) ERROR_BREAK(52); /*too long backward distance*/
+      backward = start - distance;
+
+      if(!ucvector_resize(out, (*pos) + length)) ERROR_BREAK(83 /*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] + 256u * in[p + 1]; p += 2;
+  NLEN = in[p] + 256u * 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(!ucvector_resize(out, (*pos) + LEN)) return 83; /*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;
+}
+
+static unsigned lodepng_inflatev(ucvector* out,
+                                 const unsigned char* in, size_t insize,
+                                 const LodePNGDecompressSettings* settings)
+{
+  /*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;
+
+  (void)settings;
+
+  while(!BFINAL)
+  {
+    unsigned BTYPE;
+    if(bp + 2 >= insize * 8) return 52; /*error, bit pointer will jump past memory*/
+    BFINAL = readBitFromStream(&bp, in);
+    BTYPE = 1u * readBitFromStream(&bp, in);
+    BTYPE += 2u * readBitFromStream(&bp, in);
+
+    if(BTYPE == 3) return 20; /*error: invalid BTYPE*/
+    else if(BTYPE == 0) error = inflateNoCompression(out, in, &bp, &pos, insize); /*no compression*/
+    else error = inflateHuffmanBlock(out, in, &bp, &pos, insize, BTYPE); /*compression, BTYPE 01 or 10*/
+
+    if(error) return error;
+  }
+
+  return error;
+}
+
+unsigned lodepng_inflate(unsigned char** out, size_t* outsize,
+                         const unsigned char* in, size_t insize,
+                         const LodePNGDecompressSettings* settings)
+{
+  unsigned error;
+  ucvector v;
+  ucvector_init_buffer(&v, *out, *outsize);
+  error = lodepng_inflatev(&v, in, insize, settings);
+  *out = v.data;
+  *outsize = v.size;
+  return error;
+}
+
+static unsigned inflate(unsigned char** out, size_t* outsize,
+                        const unsigned char* in, size_t insize,
+                        const LodePNGDecompressSettings* settings)
+{
+  if(settings->custom_inflate)
+  {
+    return settings->custom_inflate(out, outsize, in, insize, settings);
+  }
+  else
+  {
+    return lodepng_inflate(out, outsize, in, insize, settings);
+  }
+}
+
+#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);
+}
+
+/*3 bytes of data get encoded into two bytes. The hash cannot use more than 3
+bytes as input because 3 is the minimum match length for deflate*/
+static const unsigned HASH_NUM_VALUES = 65536;
+static const unsigned HASH_BIT_MASK = 65535; /*HASH_NUM_VALUES - 1, but C90 does not like that as initializer*/
+
+typedef struct Hash
+{
+  int* head; /*hash value to head circular pos - can be outdated if went around window*/
+  /*circular pos to prev circular pos*/
+  unsigned short* chain;
+  int* val; /*circular pos to hash value*/
+
+  /*TODO: do this not only for zeros but for any repeated byte. However for PNG
+  it's always going to be the zeros that dominate, so not important for PNG*/
+  int* headz; /*similar to head, but for chainz*/
+  unsigned short* chainz; /*those with same amount of zeros*/
+  unsigned short* zeros; /*length of zeros streak, used as a second hash chain*/
+} Hash;
+
+static unsigned hash_init(Hash* hash, unsigned windowsize)
+{
+  unsigned i;
+  hash->head = (int*)lodepng_malloc(sizeof(int) * HASH_NUM_VALUES);
+  hash->val = (int*)lodepng_malloc(sizeof(int) * windowsize);
+  hash->chain = (unsigned short*)lodepng_malloc(sizeof(unsigned short) * windowsize);
+
+  hash->zeros = (unsigned short*)lodepng_malloc(sizeof(unsigned short) * windowsize);
+  hash->headz = (int*)lodepng_malloc(sizeof(int) * (MAX_SUPPORTED_DEFLATE_LENGTH + 1));
+  hash->chainz = (unsigned short*)lodepng_malloc(sizeof(unsigned short) * windowsize);
+
+  if(!hash->head || !hash->chain || !hash->val  || !hash->headz|| !hash->chainz || !hash->zeros)
+  {
+    return 83; /*alloc fail*/
+  }
+
+  /*initialize hash table*/
+  for(i = 0; i < HASH_NUM_VALUES; i++) hash->head[i] = -1;
+  for(i = 0; i < windowsize; i++) hash->val[i] = -1;
+  for(i = 0; i < windowsize; i++) hash->chain[i] = i; /*same value as index indicates uninitialized*/
+
+  for(i = 0; i <= MAX_SUPPORTED_DEFLATE_LENGTH; i++) hash->headz[i] = -1;
+  for(i = 0; i < windowsize; i++) hash->chainz[i] = i; /*same value as index indicates uninitialized*/
+
+  return 0;
+}
+
+static void hash_cleanup(Hash* hash)
+{
+  lodepng_free(hash->head);
+  lodepng_free(hash->val);
+  lodepng_free(hash->chain);
+
+  lodepng_free(hash->zeros);
+  lodepng_free(hash->headz);
+  lodepng_free(hash->chainz);
+}
+
+
+
+static unsigned getHash(const unsigned char* data, size_t size, size_t pos)
+{
+  unsigned result = 0;
+  if (pos + 2 < size)
+  {
+    /*A simple shift and xor hash is used. Since the data of PNGs is dominated
+    by zeroes due to the filters, a better hash does not have a significant
+    effect on speed in traversing the chain, and causes more time spend on
+    calculating the hash.*/
+    result ^= (unsigned)(data[pos + 0] << 0u);
+    result ^= (unsigned)(data[pos + 1] << 4u);
+    result ^= (unsigned)(data[pos + 2] << 8u);
+  } else {
+    size_t amount, i;
+    if(pos >= size) return 0;
+    amount = size - pos;
+    for(i = 0; i < amount; i++) result ^= (unsigned)(data[pos + i] << (i * 8u));
+  }
+  return result & HASH_BIT_MASK;
+}
+
+static unsigned countZeros(const unsigned char* data, size_t size, size_t pos)
+{
+  const unsigned char* start = data + pos;
+  const unsigned char* end = start + MAX_SUPPORTED_DEFLATE_LENGTH;
+  if(end > data + size) end = data + size;
+  data = start;
+  while (data != end && *data == 0) data++;
+  /*subtracting two addresses returned as 32-bit number (max value is MAX_SUPPORTED_DEFLATE_LENGTH)*/
+  return (unsigned)(data - start);
+}
+
+/*wpos = pos & (windowsize - 1)*/
+static void updateHashChain(Hash* hash, size_t wpos, unsigned hashval, unsigned short numzeros)
+{
+  hash->val[wpos] = (int)hashval;
+  if(hash->head[hashval] != -1) hash->chain[wpos] = hash->head[hashval];
+  hash->head[hashval] = wpos;
+
+  hash->zeros[wpos] = numzeros;
+  if(hash->headz[numzeros] != -1) hash->chainz[wpos] = hash->headz[numzeros];
+  hash->headz[numzeros] = wpos;
+}
+
+/*
+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, Hash* hash,
+                           const unsigned char* in, size_t inpos, size_t insize, unsigned windowsize,
+                           unsigned minmatch, unsigned nicematch, unsigned lazymatching)
+{
+  size_t pos;
+  unsigned i, error = 0;
+  /*for large window lengths, assume the user wants no compression loss. Otherwise, max hash chain length speedup.*/
+  unsigned maxchainlength = windowsize >= 8192 ? windowsize : windowsize / 8;
+  unsigned maxlazymatch = windowsize >= 8192 ? MAX_SUPPORTED_DEFLATE_LENGTH : 64;
+
+  unsigned usezeros = 1; /*not sure if setting it to false for windowsize < 8192 is better or worse*/
+  unsigned numzeros = 0;
+
+  unsigned offset; /*the offset represents the distance in LZ77 terminology*/
+  unsigned length;
+  unsigned lazy = 0;
+  unsigned lazylength = 0, lazyoffset = 0;
+  unsigned hashval;
+  unsigned current_offset, current_length;
+  unsigned prev_offset;
+  const unsigned char *lastptr, *foreptr, *backptr;
+  unsigned hashpos;
+
+  if(windowsize <= 0 || windowsize > 32768) return 60; /*error: windowsize smaller/larger than allowed*/
+  if((windowsize & (windowsize - 1)) != 0) return 90; /*error: must be power of two*/
+
+  if(nicematch > MAX_SUPPORTED_DEFLATE_LENGTH) nicematch = MAX_SUPPORTED_DEFLATE_LENGTH;
+
+  for(pos = inpos; pos < insize; pos++)
+  {
+    size_t wpos = pos & (windowsize - 1); /*position for in 'circular' hash buffers*/
+    unsigned chainlength = 0;
+
+    hashval = getHash(in, insize, pos);
+
+    if(usezeros && hashval == 0)
+    {
+      if (numzeros == 0) numzeros = countZeros(in, insize, pos);
+      else if (pos + numzeros > insize || in[pos + numzeros - 1] != 0) numzeros--;
+    }
+    else
+    {
+      numzeros = 0;
+    }
+
+    updateHashChain(hash, wpos, hashval, numzeros);
+
+    /*the length and offset found for the current position*/
+    length = 0;
+    offset = 0;
+
+    hashpos = hash->chain[wpos];
+
+    lastptr = &in[insize < pos + MAX_SUPPORTED_DEFLATE_LENGTH ? insize : pos + MAX_SUPPORTED_DEFLATE_LENGTH];
+
+    /*search for the longest string*/
+    prev_offset = 0;
+    for(;;)
+    {
+      if(chainlength++ >= maxchainlength) break;
+      current_offset = hashpos <= wpos ? wpos - hashpos : wpos - hashpos + windowsize;
+
+      if(current_offset < prev_offset) break; /*stop when went completely around the circular buffer*/
+      prev_offset = current_offset;
+      if(current_offset > 0)
+      {
+        /*test the next characters*/
+        foreptr = &in[pos];
+        backptr = &in[pos - current_offset];
+
+        /*common case in PNGs is lots of zeros. Quickly skip over them as a speedup*/
+        if(numzeros >= 3)
+        {
+          unsigned skip = hash->zeros[hashpos];
+          if(skip > numzeros) skip = numzeros;
+          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*/
+          /*jump out once a length of max length is found (speed gain). This also jumps
+          out if length is MAX_SUPPORTED_DEFLATE_LENGTH*/
+          if(current_length >= nicematch) break;
+        }
+      }
+
+      if(hashpos == hash->chain[hashpos]) break;
+      
+      if(numzeros >= 3 && length > numzeros) {
+        hashpos = hash->chainz[hashpos];
+        if(hash->zeros[hashpos] != numzeros) break;
+      } else {
+        hashpos = hash->chain[hashpos];
+        /*outdated hash value, happens if particular value was not encountered in whole last window*/
+        if(hash->val[hashpos] != (int)hashval) break;
+      }
+    }
+
+    if(lazymatching)
+    {
+      if(!lazy && length >= 3 && length <= maxlazymatch && length < MAX_SUPPORTED_DEFLATE_LENGTH)
+      {
+        lazy = 1;
+        lazylength = length;
+        lazyoffset = offset;
+        continue; /*try the next byte*/
+      }
+      if(lazy)
+      {
+        lazy = 0;
+        if(pos == 0) ERROR_BREAK(81);
+        if(length > lazylength + 1)
+        {
+          /*push the previous character as literal*/
+          if(!uivector_push_back(out, in[pos - 1])) ERROR_BREAK(83 /*alloc fail*/);
+        }
+        else
+        {
+          length = lazylength;
+          offset = lazyoffset;
+          hash->head[hashval] = -1; /*the same hashchain update will be done, this ensures no wrong alteration*/
+          hash->headz[numzeros] = -1; /*idem*/
+          pos--;
+        }
+      }
+    }
+    if(length >= 3 && offset > windowsize) ERROR_BREAK(86 /*too big (or overflown negative) offset*/);
+
+    /*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(83 /*alloc fail*/);
+    }
+    else if(length < minmatch || (length == 3 && offset > 4096))
+    {
+      /*compensate for the fact that longer offsets have more extra bits, a
+      length of only 3 may be not worth it then*/
+      if(!uivector_push_back(out, in[pos])) ERROR_BREAK(83 /*alloc fail*/);
+    }
+    else
+    {
+      addLengthDistance(out, length, offset);
+      for(i = 1; i < length; i++)
+      {
+        pos++;
+        wpos = pos & (windowsize - 1);
+        hashval = getHash(in, insize, pos);
+        if(usezeros && hashval == 0)
+        {
+          if (numzeros == 0) numzeros = countZeros(in, insize, pos);
+          else if (pos + numzeros > insize || in[pos + numzeros - 1] != 0) numzeros--;
+        }
+        else
+        {
+          numzeros = 0;
+        }
+        updateHashChain(hash, wpos, hashval, numzeros);
+      }
+    }
+  } /*end of the loop through each character of input*/
+
+  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 + 65534) / 65535;
+  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, size_t* bp, Hash* hash,
+                               const unsigned char* data, size_t datapos, size_t dataend,
+                               const LodePNGCompressSettings* settings, unsigned final)
+{
+  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;
+  size_t datasize = dataend - datapos;
+
+  /*
+  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 = final;
+  size_t numcodes_ll, numcodes_d, i;
+  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 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->use_lz77)
+    {
+      error = encodeLZ77(&lz77_encoded, hash, data, datapos, dataend, settings->windowsize,
+                         settings->minmatch, settings->nicematch, settings->lazymatching);
+      if(error) break;
+    }
+    else
+    {
+      if(!uivector_resize(&lz77_encoded, datasize)) ERROR_BREAK(83 /*alloc fail*/);
+      for(i = datapos; i < dataend; i++) lz77_encoded.data[i] = data[i]; /*no LZ77, but still will be Huffman compressed*/
+    }
+
+    if(!uivector_resizev(&frequencies_ll, 286, 0)) ERROR_BREAK(83 /*alloc fail*/);
+    if(!uivector_resizev(&frequencies_d, 30, 0)) ERROR_BREAK(83 /*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, 257, frequencies_ll.size, 15);
+    if(error) break;
+    /*2, not 1, is chosen for mincodes: some buggy PNG decoders require at least 2 symbols in the dist tree*/
+    error = HuffmanTree_makeFromFrequencies(&tree_d, frequencies_d.data, 2, 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(83 /*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, frequencies_cl.size, 7);
+    if(error) break;
+
+    if(!uivector_resize(&bitlen_cl, tree_cl.numcodes)) ERROR_BREAK(83 /*alloc fail*/);
+    for(i = 0; i < tree_cl.numcodes; 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(83 /*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;
+    /*trim zeroes for HCLEN. HLIT and HDIST were already trimmed at tree creation*/
+    while(!bitlen_cl.data[HCLEN + 4 - 1] && HCLEN > 0) HCLEN--;
+    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, size_t* bp, Hash* hash,
+                             const unsigned char* data,
+                             size_t datapos, size_t dataend,
+                             const LodePNGCompressSettings* settings, unsigned final)
+{
+  HuffmanTree tree_ll; /*tree for literal values and length codes*/
+  HuffmanTree tree_d; /*tree for distance codes*/
+
+  unsigned BFINAL = final;
+  unsigned error = 0;
+  size_t i;
+
+  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->use_lz77) /*LZ77 encoded*/
+  {
+    uivector lz77_encoded;
+    uivector_init(&lz77_encoded);
+    error = encodeLZ77(&lz77_encoded, hash, data, datapos, dataend, settings->windowsize,
+                       settings->minmatch, settings->nicematch, settings->lazymatching);
+    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 = datapos; i < dataend; 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_deflatev(ucvector* out, const unsigned char* in, size_t insize,
+                                 const LodePNGCompressSettings* settings)
+{
+  unsigned error = 0;
+  size_t i, blocksize, numdeflateblocks;
+  size_t bp = 0; /*the bit pointer*/
+  Hash hash;
+
+  if(settings->btype > 2) return 61;
+  else if(settings->btype == 0) return deflateNoCompression(out, in, insize);
+  else if(settings->btype == 1) blocksize = insize;
+  else /*if(settings->btype == 2)*/
+  {
+    blocksize = insize / 8 + 8;
+    if(blocksize < 65535) blocksize = 65535;
+  }
+
+  numdeflateblocks = (insize + blocksize - 1) / blocksize;
+  if(numdeflateblocks == 0) numdeflateblocks = 1;
+
+  error = hash_init(&hash, settings->windowsize);
+  if(error) return error;
+
+  for(i = 0; i < numdeflateblocks && !error; i++)
+  {
+    unsigned final = (i == numdeflateblocks - 1);
+    size_t start = i * blocksize;
+    size_t end = start + blocksize;
+    if(end > insize) end = insize;
+
+    if(settings->btype == 1) error = deflateFixed(out, &bp, &hash, in, start, end, settings, final);
+    else if(settings->btype == 2) error = deflateDynamic(out, &bp, &hash, in, start, end, settings, final);
+  }
+
+  hash_cleanup(&hash);
+
+  return error;
+}
+
+unsigned lodepng_deflate(unsigned char** out, size_t* outsize,
+                         const unsigned char* in, size_t insize,
+                         const LodePNGCompressSettings* settings)
+{
+  unsigned error;
+  ucvector v;
+  ucvector_init_buffer(&v, *out, *outsize);
+  error = lodepng_deflatev(&v, in, insize, settings);
+  *out = v.data;
+  *outsize = v.size;
+  return error;
+}
+
+static unsigned deflate(unsigned char** out, size_t* outsize,
+                        const unsigned char* in, size_t insize,
+                        const LodePNGCompressSettings* settings)
+{
+  if(settings->custom_deflate)
+  {
+    return settings->custom_deflate(out, outsize, in, insize, settings);
+  }
+  else
+  {
+    return lodepng_deflate(out, outsize, in, insize, settings);
+  }
+}
+
+#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 += (*data++);
+      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 LodePNGDecompressSettings* settings)
+{
+  unsigned error = 0;
+  unsigned CM, CINFO, FDICT;
+
+  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;
+  }
+
+  error = inflate(out, outsize, in + 2, insize - 2, settings);
+  if(error) return error;
+
+  if(!settings->ignore_adler32)
+  {
+    unsigned ADLER32 = lodepng_read32bitInt(&in[insize - 4]);
+    unsigned checksum = adler32(*out, (unsigned)(*outsize));
+    if(checksum != ADLER32) return 58; /*error, adler checksum not correct, data must be corrupted*/
+  }
+
+  return 0; /*no error*/
+}
+
+static unsigned zlib_decompress(unsigned char** out, size_t* outsize, const unsigned char* in,
+                                size_t insize, const LodePNGDecompressSettings* settings)
+{
+  if(settings->custom_zlib)
+  {
+    return settings->custom_zlib(out, outsize, in, insize, settings);
+  }
+  else
+  {
+    return lodepng_zlib_decompress(out, outsize, in, insize, settings);
+  }
+}
+
+#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 LodePNGCompressSettings* 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 outv;
+  size_t i;
+  unsigned error;
+  unsigned char* deflatedata = 0;
+  size_t deflatesize = 0;
+
+  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));
+
+  error = deflate(&deflatedata, &deflatesize, in, insize, settings);
+
+  if(!error)
+  {
+    ADLER32 = adler32(in, (unsigned)insize);
+    for(i = 0; i < deflatesize; i++) ucvector_push_back(&outv, deflatedata[i]);
+    lodepng_free(deflatedata);
+    lodepng_add32bitInt(&outv, ADLER32);
+  }
+
+  *out = outv.data;
+  *outsize = outv.size;
+
+  return error;
+}
+
+/* compress using the default or custom zlib function */
+static unsigned zlib_compress(unsigned char** out, size_t* outsize, const unsigned char* in,
+                              size_t insize, const LodePNGCompressSettings* settings)
+{
+  if(settings->custom_zlib)
+  {
+    return settings->custom_zlib(out, outsize, in, insize, settings);
+  }
+  else
+  {
+    return lodepng_zlib_compress(out, outsize, in, insize, settings);
+  }
+}
+
+#endif /*LODEPNG_COMPILE_ENCODER*/
+
+#else /*no LODEPNG_COMPILE_ZLIB*/
+
+#ifdef LODEPNG_COMPILE_DECODER
+static unsigned zlib_decompress(unsigned char** out, size_t* outsize, const unsigned char* in,
+                                size_t insize, const LodePNGDecompressSettings* settings)
+{
+  if (!settings->custom_zlib) return 87; /*no custom zlib function provided */
+  return settings->custom_zlib(out, outsize, in, insize, settings);
+}
+#endif /*LODEPNG_COMPILE_DECODER*/
+#ifdef LODEPNG_COMPILE_ENCODER
+static unsigned zlib_compress(unsigned char** out, size_t* outsize, const unsigned char* in,
+                              size_t insize, const LodePNGCompressSettings* settings)
+{
+  if (!settings->custom_zlib) return 87; /*no custom zlib function provided */
+  return settings->custom_zlib(out, outsize, in, insize, settings);
+}
+#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_compress_settings_init(LodePNGCompressSettings* settings)
+{
+  /*compress with dynamic huffman tree (not in the mathematical sense, just not the predefined one)*/
+  settings->btype = 2;
+  settings->use_lz77 = 1;
+  settings->windowsize = DEFAULT_WINDOWSIZE;
+  settings->minmatch = 3;
+  settings->nicematch = 128;
+  settings->lazymatching = 1;
+
+  settings->custom_zlib = 0;
+  settings->custom_deflate = 0;
+  settings->custom_context = 0;
+}
+
+const LodePNGCompressSettings lodepng_default_compress_settings = {2, 1, DEFAULT_WINDOWSIZE, 3, 128, 1, 0, 0, 0};
+
+
+#endif /*LODEPNG_COMPILE_ENCODER*/
+
+#ifdef LODEPNG_COMPILE_DECODER
+
+void lodepng_decompress_settings_init(LodePNGDecompressSettings* settings)
+{
+  settings->ignore_adler32 = 0;
+
+  settings->custom_zlib = 0;
+  settings->custom_inflate = 0;
+  settings->custom_context = 0;
+}
+
+const LodePNGDecompressSettings lodepng_default_decompress_settings = {0, 0, 0, 0};
+
+#endif /*LODEPNG_COMPILE_DECODER*/
+
+/* ////////////////////////////////////////////////////////////////////////// */
+/* ////////////////////////////////////////////////////////////////////////// */
+/* // End of Zlib related code. Begin of PNG related code.                 // */
+/* ////////////////////////////////////////////////////////////////////////// */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+#ifdef LODEPNG_COMPILE_PNG
+
+/* ////////////////////////////////////////////////////////////////////////// */
+/* / CRC32                                                                  / */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+/* CRC polynomial: 0xedb88320 */
+static unsigned lodepng_crc32_table[256] = {
+           0u, 1996959894u, 3993919788u, 2567524794u,  124634137u, 1886057615u, 3915621685u, 2657392035u,
+   249268274u, 2044508324u, 3772115230u, 2547177864u,  162941995u, 2125561021u, 3887607047u, 2428444049u,
+   498536548u, 1789927666u, 4089016648u, 2227061214u,  450548861u, 1843258603u, 4107580753u, 2211677639u,
+   325883990u, 1684777152u, 4251122042u, 2321926636u,  335633487u, 1661365465u, 4195302755u, 2366115317u,
+   997073096u, 1281953886u, 3579855332u, 2724688242u, 1006888145u, 1258607687u, 3524101629u, 2768942443u,
+   901097722u, 1119000684u, 3686517206u, 2898065728u,  853044451u, 1172266101u, 3705015759u, 2882616665u,
+   651767980u, 1373503546u, 3369554304u, 3218104598u,  565507253u, 1454621731u, 3485111705u, 3099436303u,
+   671266974u, 1594198024u, 3322730930u, 2970347812u,  795835527u, 1483230225u, 3244367275u, 3060149565u,
+  1994146192u,   31158534u, 2563907772u, 4023717930u, 1907459465u,  112637215u, 2680153253u, 3904427059u,
+  2013776290u,  251722036u, 2517215374u, 3775830040u, 2137656763u,  141376813u, 2439277719u, 3865271297u,
+  1802195444u,  476864866u, 2238001368u, 4066508878u, 1812370925u,  453092731u, 2181625025u, 4111451223u,
+  1706088902u,  314042704u, 2344532202u, 4240017532u, 1658658271u,  366619977u, 2362670323u, 4224994405u,
+  1303535960u,  984961486u, 2747007092u, 3569037538u, 1256170817u, 1037604311u, 2765210733u, 3554079995u,
+  1131014506u,  879679996u, 2909243462u, 3663771856u, 1141124467u,  855842277u, 2852801631u, 3708648649u,
+  1342533948u,  654459306u, 3188396048u, 3373015174u, 1466479909u,  544179635u, 3110523913u, 3462522015u,
+  1591671054u,  702138776u, 2966460450u, 3352799412u, 1504918807u,  783551873u, 3082640443u, 3233442989u,
+  3988292384u, 2596254646u,   62317068u, 1957810842u, 3939845945u, 2647816111u,   81470997u, 1943803523u,
+  3814918930u, 2489596804u,  225274430u, 2053790376u, 3826175755u, 2466906013u,  167816743u, 2097651377u,
+  4027552580u, 2265490386u,  503444072u, 1762050814u, 4150417245u, 2154129355u,  426522225u, 1852507879u,
+  4275313526u, 2312317920u,  282753626u, 1742555852u, 4189708143u, 2394877945u,  397917763u, 1622183637u,
+  3604390888u, 2714866558u,  953729732u, 1340076626u, 3518719985u, 2797360999u, 1068828381u, 1219638859u,
+  3624741850u, 2936675148u,  906185462u, 1090812512u, 3747672003u, 2825379669u,  829329135u, 1181335161u,
+  3412177804u, 3160834842u,  628085408u, 1382605366u, 3423369109u, 3138078467u,  570562233u, 1426400815u,
+  3317316542u, 2998733608u,  733239954u, 1555261956u, 3268935591u, 3050360625u,  752459403u, 1541320221u,
+  2607071920u, 3965973030u, 1969922972u,   40735498u, 2617837225u, 3943577151u, 1913087877u,   83908371u,
+  2512341634u, 3803740692u, 2075208622u,  213261112u, 2463272603u, 3855990285u, 2094854071u,  198958881u,
+  2262029012u, 4057260610u, 1759359992u,  534414190u, 2176718541u, 4139329115u, 1873836001u,  414664567u,
+  2282248934u, 4279200368u, 1711684554u,  285281116u, 2405801727u, 4167216745u, 1634467795u,  376229701u,
+  2685067896u, 3608007406u, 1308918612u,  956543938u, 2808555105u, 3495958263u, 1231636301u, 1047427035u,
+  2932959818u, 3654703836u, 1088359270u,  936918000u, 2847714899u, 3736837829u, 1202900863u,  817233897u,
+  3183342108u, 3401237130u, 1404277552u,  615818150u, 3134207493u, 3453421203u, 1423857449u,  601450431u,
+  3009837614u, 3294710456u, 1567103746u,  711928724u, 3020668471u, 3272380065u, 1510334235u,  755167117u
+};
+
+/*Return the CRC of the bytes buf[0..len-1].*/
+unsigned lodepng_crc32(const unsigned char* buf, size_t len)
+{
+  unsigned c = 0xffffffffL;
+  size_t n;
+
+  for(n = 0; n < len; n++)
+  {
+    c = lodepng_crc32_table[(c ^ buf[n]) & 0xff] ^ (c >> 8);
+  }
+  return c ^ 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] = (char)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_ancillary(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 = lodepng_crc32(&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 = lodepng_crc32(&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_chunk_append(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*)lodepng_realloc(*out, new_length);
+  if(!new_buffer) return 83; /*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_chunk_create(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*)lodepng_realloc(*out, new_length);
+  if(!new_buffer) return 83; /*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] = (unsigned char)type[0];
+  chunk[5] = (unsigned char)type[1];
+  chunk[6] = (unsigned char)type[2];
+  chunk[7] = (unsigned char)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(LodePNGColorType 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(LodePNGColorType 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 lodepng_get_bpp_lct(LodePNGColorType colortype, unsigned bitdepth)
+{
+  /*bits per pixel is amount of channels * bits per channel*/
+  return getNumColorChannels(colortype) * bitdepth;
+}
+
+/* ////////////////////////////////////////////////////////////////////////// */
+
+void lodepng_color_mode_init(LodePNGColorMode* info)
+{
+  info->key_defined = 0;
+  info->key_r = info->key_g = info->key_b = 0;
+  info->colortype = LCT_RGBA;
+  info->bitdepth = 8;
+  info->palette = 0;
+  info->palettesize = 0;
+}
+
+void lodepng_color_mode_cleanup(LodePNGColorMode* info)
+{
+  lodepng_palette_clear(info);
+}
+
+unsigned lodepng_color_mode_copy(LodePNGColorMode* dest, const LodePNGColorMode* source)
+{
+  size_t i;
+  lodepng_color_mode_cleanup(dest);
+  *dest = *source;
+  if(source->palette)
+  {
+    dest->palette = (unsigned char*)lodepng_malloc(1024);
+    if(!dest->palette && source->palettesize) return 83; /*alloc fail*/
+    for(i = 0; i < source->palettesize * 4; i++) dest->palette[i] = source->palette[i];
+  }
+  return 0;
+}
+
+static int lodepng_color_mode_equal(const LodePNGColorMode* a, const LodePNGColorMode* b)
+{
+  size_t i;
+  if(a->colortype != b->colortype) return 0;
+  if(a->bitdepth != b->bitdepth) return 0;
+  if(a->key_defined != b->key_defined) return 0;
+  if(a->key_defined)
+  {
+    if(a->key_r != b->key_r) return 0;
+    if(a->key_g != b->key_g) return 0;
+    if(a->key_b != b->key_b) return 0;
+  }
+  if(a->palettesize != b->palettesize) return 0;
+  for(i = 0; i < a->palettesize * 4; i++)
+  {
+    if(a->palette[i] != b->palette[i]) return 0;
+  }
+  return 1;
+}
+
+void lodepng_palette_clear(LodePNGColorMode* info)
+{
+  if(info->palette) lodepng_free(info->palette);
+  info->palette = 0;
+  info->palettesize = 0;
+}
+
+unsigned lodepng_palette_add(LodePNGColorMode* 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->palette) /*allocate palette if empty*/
+  {
+    /*room for 256 colors with 4 bytes each*/
+    data = (unsigned char*)lodepng_realloc(info->palette, 1024);
+    if(!data) return 83; /*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_get_bpp(const LodePNGColorMode* info)
+{
+  /*calculate bits per pixel out of colortype and bitdepth*/
+  return lodepng_get_bpp_lct(info->colortype, info->bitdepth);
+}
+
+unsigned lodepng_get_channels(const LodePNGColorMode* info)
+{
+  return getNumColorChannels(info->colortype);
+}
+
+unsigned lodepng_is_greyscale_type(const LodePNGColorMode* info)
+{
+  return info->colortype == LCT_GREY || info->colortype == LCT_GREY_ALPHA;
+}
+
+unsigned lodepng_is_alpha_type(const LodePNGColorMode* info)
+{
+  return (info->colortype & 4) != 0; /*4 or 6*/
+}
+
+unsigned lodepng_is_palette_type(const LodePNGColorMode* info)
+{
+  return info->colortype == LCT_PALETTE;
+}
+
+unsigned lodepng_has_palette_alpha(const LodePNGColorMode* info)
+{
+  size_t i;
+  for(i = 0; i < info->palettesize; i++)
+  {
+    if(info->palette[i * 4 + 3] < 255) return 1;
+  }
+  return 0;
+}
+
+unsigned lodepng_can_have_alpha(const LodePNGColorMode* info)
+{
+  return info->key_defined
+      || lodepng_is_alpha_type(info)
+      || lodepng_has_palette_alpha(info);
+}
+
+size_t lodepng_get_raw_size(unsigned w, unsigned h, const LodePNGColorMode* color)
+{
+  return (w * h * lodepng_get_bpp(color) + 7) / 8;
+}
+
+size_t lodepng_get_raw_size_lct(unsigned w, unsigned h, LodePNGColorType colortype, unsigned bitdepth)
+{
+  return (w * h * lodepng_get_bpp_lct(colortype, bitdepth) + 7) / 8;
+}
+
+
+#ifdef LODEPNG_COMPILE_PNG
+#ifdef LODEPNG_COMPILE_DECODER
+/*in an idat chunk, each scanline is a multiple of 8 bits, unlike the lodepng output buffer*/
+static size_t lodepng_get_raw_size_idat(unsigned w, unsigned h, const LodePNGColorMode* color)
+{
+  return h * ((w * lodepng_get_bpp(color) + 7) / 8);
+}
+#endif /*LODEPNG_COMPILE_DECODER*/
+#endif /*LODEPNG_COMPILE_PNG*/
+
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+
+static void LodePNGUnknownChunks_init(LodePNGInfo* info)
+{
+  unsigned i;
+  for(i = 0; i < 3; i++) info->unknown_chunks_data[i] = 0;
+  for(i = 0; i < 3; i++) info->unknown_chunks_size[i] = 0;
+}
+
+static void LodePNGUnknownChunks_cleanup(LodePNGInfo* info)
+{
+  unsigned i;
+  for(i = 0; i < 3; i++) lodepng_free(info->unknown_chunks_data[i]);
+}
+
+static unsigned LodePNGUnknownChunks_copy(LodePNGInfo* dest, const LodePNGInfo* src)
+{
+  unsigned i;
+
+  LodePNGUnknownChunks_cleanup(dest);
+
+  for(i = 0; i < 3; i++)
+  {
+    size_t j;
+    dest->unknown_chunks_size[i] = src->unknown_chunks_size[i];
+    dest->unknown_chunks_data[i] = (unsigned char*)lodepng_malloc(src->unknown_chunks_size[i]);
+    if(!dest->unknown_chunks_data[i] && dest->unknown_chunks_size[i]) return 83; /*alloc fail*/
+    for(j = 0; j < src->unknown_chunks_size[i]; j++)
+    {
+      dest->unknown_chunks_data[i][j] = src->unknown_chunks_data[i][j];
+    }
+  }
+
+  return 0;
+}
+
+/******************************************************************************/
+
+static void LodePNGText_init(LodePNGInfo* info)
+{
+  info->text_num = 0;
+  info->text_keys = NULL;
+  info->text_strings = NULL;
+}
+
+static void LodePNGText_cleanup(LodePNGInfo* info)
+{
+  size_t i;
+  for(i = 0; i < info->text_num; i++)
+  {
+    string_cleanup(&info->text_keys[i]);
+    string_cleanup(&info->text_strings[i]);
+  }
+  lodepng_free(info->text_keys);
+  lodepng_free(info->text_strings);
+}
+
+static unsigned LodePNGText_copy(LodePNGInfo* dest, const LodePNGInfo* source)
+{
+  size_t i = 0;
+  dest->text_keys = 0;
+  dest->text_strings = 0;
+  dest->text_num = 0;
+  for(i = 0; i < source->text_num; i++)
+  {
+    CERROR_TRY_RETURN(lodepng_add_text(dest, source->text_keys[i], source->text_strings[i]));
+  }
+  return 0;
+}
+
+void lodepng_clear_text(LodePNGInfo* info)
+{
+  LodePNGText_cleanup(info);
+}
+
+unsigned lodepng_add_text(LodePNGInfo* info, const char* key, const char* str)
+{
+  char** new_keys = (char**)(lodepng_realloc(info->text_keys, sizeof(char*) * (info->text_num + 1)));
+  char** new_strings = (char**)(lodepng_realloc(info->text_strings, sizeof(char*) * (info->text_num + 1)));
+  if(!new_keys || !new_strings)
+  {
+    lodepng_free(new_keys);
+    lodepng_free(new_strings);
+    return 83; /*alloc fail*/
+  }
+
+  info->text_num++;
+  info->text_keys = new_keys;
+  info->text_strings = new_strings;
+
+  string_init(&info->text_keys[info->text_num - 1]);
+  string_set(&info->text_keys[info->text_num - 1], key);
+
+  string_init(&info->text_strings[info->text_num - 1]);
+  string_set(&info->text_strings[info->text_num - 1], str);
+
+  return 0;
+}
+
+/******************************************************************************/
+
+static void LodePNGIText_init(LodePNGInfo* info)
+{
+  info->itext_num = 0;
+  info->itext_keys = NULL;
+  info->itext_langtags = NULL;
+  info->itext_transkeys = NULL;
+  info->itext_strings = NULL;
+}
+
+static void LodePNGIText_cleanup(LodePNGInfo* info)
+{
+  size_t i;
+  for(i = 0; i < info->itext_num; i++)
+  {
+    string_cleanup(&info->itext_keys[i]);
+    string_cleanup(&info->itext_langtags[i]);
+    string_cleanup(&info->itext_transkeys[i]);
+    string_cleanup(&info->itext_strings[i]);
+  }
+  lodepng_free(info->itext_keys);
+  lodepng_free(info->itext_langtags);
+  lodepng_free(info->itext_transkeys);
+  lodepng_free(info->itext_strings);
+}
+
+static unsigned LodePNGIText_copy(LodePNGInfo* dest, const LodePNGInfo* source)
+{
+  size_t i = 0;
+  dest->itext_keys = 0;
+  dest->itext_langtags = 0;
+  dest->itext_transkeys = 0;
+  dest->itext_strings = 0;
+  dest->itext_num = 0;
+  for(i = 0; i < source->itext_num; i++)
+  {
+    CERROR_TRY_RETURN(lodepng_add_itext(dest, source->itext_keys[i], source->itext_langtags[i],
+                                        source->itext_transkeys[i], source->itext_strings[i]));
+  }
+  return 0;
+}
+
+void lodepng_clear_itext(LodePNGInfo* info)
+{
+  LodePNGIText_cleanup(info);
+}
+
+unsigned lodepng_add_itext(LodePNGInfo* info, const char* key, const char* langtag,
+                           const char* transkey, const char* str)
+{
+  char** new_keys = (char**)(lodepng_realloc(info->itext_keys, sizeof(char*) * (info->itext_num + 1)));
+  char** new_langtags = (char**)(lodepng_realloc(info->itext_langtags, sizeof(char*) * (info->itext_num + 1)));
+  char** new_transkeys = (char**)(lodepng_realloc(info->itext_transkeys, sizeof(char*) * (info->itext_num + 1)));
+  char** new_strings = (char**)(lodepng_realloc(info->itext_strings, sizeof(char*) * (info->itext_num + 1)));
+  if(!new_keys || !new_langtags || !new_transkeys || !new_strings)
+  {
+    lodepng_free(new_keys);
+    lodepng_free(new_langtags);
+    lodepng_free(new_transkeys);
+    lodepng_free(new_strings);
+    return 83; /*alloc fail*/
+  }
+
+  info->itext_num++;
+  info->itext_keys = new_keys;
+  info->itext_langtags = new_langtags;
+  info->itext_transkeys = new_transkeys;
+  info->itext_strings = new_strings;
+
+  string_init(&info->itext_keys[info->itext_num - 1]);
+  string_set(&info->itext_keys[info->itext_num - 1], key);
+
+  string_init(&info->itext_langtags[info->itext_num - 1]);
+  string_set(&info->itext_langtags[info->itext_num - 1], langtag);
+
+  string_init(&info->itext_transkeys[info->itext_num - 1]);
+  string_set(&info->itext_transkeys[info->itext_num - 1], transkey);
+
+  string_init(&info->itext_strings[info->itext_num - 1]);
+  string_set(&info->itext_strings[info->itext_num - 1], str);
+
+  return 0;
+}
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+
+void lodepng_info_init(LodePNGInfo* info)
+{
+  lodepng_color_mode_init(&info->color);
+  info->interlace_method = 0;
+  info->compression_method = 0;
+  info->filter_method = 0;
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+  info->background_defined = 0;
+  info->background_r = info->background_g = info->background_b = 0;
+
+  LodePNGText_init(info);
+  LodePNGIText_init(info);
+
+  info->time_defined = 0;
+  info->phys_defined = 0;
+
+  LodePNGUnknownChunks_init(info);
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+}
+
+void lodepng_info_cleanup(LodePNGInfo* info)
+{
+  lodepng_color_mode_cleanup(&info->color);
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+  LodePNGText_cleanup(info);
+  LodePNGIText_cleanup(info);
+
+  LodePNGUnknownChunks_cleanup(info);
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+}
+
+unsigned lodepng_info_copy(LodePNGInfo* dest, const LodePNGInfo* source)
+{
+  lodepng_info_cleanup(dest);
+  *dest = *source;
+  lodepng_color_mode_init(&dest->color);
+  CERROR_TRY_RETURN(lodepng_color_mode_copy(&dest->color, &source->color));
+
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+  CERROR_TRY_RETURN(LodePNGText_copy(dest, source));
+  CERROR_TRY_RETURN(LodePNGIText_copy(dest, source));
+
+  LodePNGUnknownChunks_init(dest);
+  CERROR_TRY_RETURN(LodePNGUnknownChunks_copy(dest, source));
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+  return 0;
+}
+
+void lodepng_info_swap(LodePNGInfo* a, LodePNGInfo* b)
+{
+  LodePNGInfo temp = *a;
+  *a = *b;
+  *b = temp;
+}
+
+/* ////////////////////////////////////////////////////////////////////////// */
+
+/*index: bitgroup index, bits: bitgroup size(1, 2 or 4), in: bitgroup value, out: octet array to add bits to*/
+static void addColorBits(unsigned char* out, size_t index, unsigned bits, unsigned in)
+{
+  unsigned m = bits == 1 ? 7 : bits == 2 ? 3 : 1; /*8 / bits - 1*/
+  /*p = the partial index in the byte, e.g. with 4 palettebits it is 0 for first half or 1 for second half*/
+  unsigned p = index & m;
+  in &= (1u << bits) - 1u; /*filter out any other bits of the input value*/
+  in = in << (bits * (m - p));
+  if(p == 0) out[index * bits / 8] = in;
+  else out[index * bits / 8] |= in;
+}
+
+typedef struct ColorTree ColorTree;
+
+/*
+One node of a color tree
+This is the data structure used to count the number of unique colors and to get a palette
+index for a color. It's like an octree, but because the alpha channel is used too, each
+node has 16 instead of 8 children.
+*/
+struct ColorTree
+{
+  ColorTree* children[16]; /*up to 16 pointers to ColorTree of next level*/
+  int index; /*the payload. Only has a meaningful value if this is in the last level*/
+};
+
+static void color_tree_init(ColorTree* tree)
+{
+  int i;
+  for(i = 0; i < 16; i++) tree->children[i] = 0;
+  tree->index = -1;
+}
+
+static void color_tree_cleanup(ColorTree* tree)
+{
+  int i;
+  for(i = 0; i < 16; i++)
+  {
+    if(tree->children[i])
+    {
+      color_tree_cleanup(tree->children[i]);
+      lodepng_free(tree->children[i]);
+    }
+  }
+}
+
+/*returns -1 if color not present, its index otherwise*/
+static int color_tree_get(ColorTree* tree, unsigned char r, unsigned char g, unsigned char b, unsigned char a)
+{
+  int bit = 0;
+  for(bit = 0; bit < 8; bit++)
+  {
+    int i = 8 * ((r >> bit) & 1) + 4 * ((g >> bit) & 1) + 2 * ((b >> bit) & 1) + 1 * ((a >> bit) & 1);
+    if(!tree->children[i]) return -1;
+    else tree = tree->children[i];
+  }
+  return tree ? tree->index : -1;
+}
+
+#ifdef LODEPNG_COMPILE_ENCODER
+static int color_tree_has(ColorTree* tree, unsigned char r, unsigned char g, unsigned char b, unsigned char a)
+{
+  return color_tree_get(tree, r, g, b, a) >= 0;
+}
+#endif /*LODEPNG_COMPILE_ENCODER*/
+
+/*color is not allowed to already exist.
+Index should be >= 0 (it's signed to be compatible with using -1 for "doesn't exist")*/
+static void color_tree_add(ColorTree* tree,
+                           unsigned char r, unsigned char g, unsigned char b, unsigned char a, unsigned index)
+{
+  int bit;
+  for(bit = 0; bit < 8; bit++)
+  {
+    int i = 8 * ((r >> bit) & 1) + 4 * ((g >> bit) & 1) + 2 * ((b >> bit) & 1) + 1 * ((a >> bit) & 1);
+    if(!tree->children[i])
+    {
+      tree->children[i] = (ColorTree*)lodepng_malloc(sizeof(ColorTree));
+      color_tree_init(tree->children[i]);
+    }
+    tree = tree->children[i];
+  }
+  tree->index = (int)index;
+}
+
+/*put a pixel, given its RGBA color, into image of any color type*/
+static unsigned rgba8ToPixel(unsigned char* out, size_t i,
+                             const LodePNGColorMode* mode, ColorTree* tree /*for palette*/,
+                             unsigned char r, unsigned char g, unsigned char b, unsigned char a)
+{
+  if(mode->colortype == LCT_GREY)
+  {
+    unsigned char grey = r; /*((unsigned short)r + g + b) / 3*/;
+    if(mode->bitdepth == 8) out[i] = grey;
+    else if(mode->bitdepth == 16) out[i * 2 + 0] = out[i * 2 + 1] = grey;
+    else
+    {
+      /*take the most significant bits of grey*/
+      grey = (grey >> (8 - mode->bitdepth)) & ((1 << mode->bitdepth) - 1);
+      addColorBits(out, i, mode->bitdepth, grey);
+    }
+  }
+  else if(mode->colortype == LCT_RGB)
+  {
+    if(mode->bitdepth == 8)
+    {
+      out[i * 3 + 0] = r;
+      out[i * 3 + 1] = g;
+      out[i * 3 + 2] = b;
+    }
+    else
+    {
+      out[i * 6 + 0] = out[i * 6 + 1] = r;
+      out[i * 6 + 2] = out[i * 6 + 3] = g;
+      out[i * 6 + 4] = out[i * 6 + 5] = b;
+    }
+  }
+  else if(mode->colortype == LCT_PALETTE)
+  {
+    int index = color_tree_get(tree, r, g, b, a);
+    if(index < 0) return 82; /*color not in palette*/
+    if(mode->bitdepth == 8) out[i] = index;
+    else addColorBits(out, i, mode->bitdepth, (unsigned)index);
+  }
+  else if(mode->colortype == LCT_GREY_ALPHA)
+  {
+    unsigned char grey = r; /*((unsigned short)r + g + b) / 3*/;
+    if(mode->bitdepth == 8)
+    {
+      out[i * 2 + 0] = grey;
+      out[i * 2 + 1] = a;
+    }
+    else if(mode->bitdepth == 16)
+    {
+      out[i * 4 + 0] = out[i * 4 + 1] = grey;
+      out[i * 4 + 2] = out[i * 4 + 3] = a;
+    }
+  }
+  else if(mode->colortype == LCT_RGBA)
+  {
+    if(mode->bitdepth == 8)
+    {
+      out[i * 4 + 0] = r;
+      out[i * 4 + 1] = g;
+      out[i * 4 + 2] = b;
+      out[i * 4 + 3] = a;
+    }
+    else
+    {
+      out[i * 8 + 0] = out[i * 8 + 1] = r;
+      out[i * 8 + 2] = out[i * 8 + 3] = g;
+      out[i * 8 + 4] = out[i * 8 + 5] = b;
+      out[i * 8 + 6] = out[i * 8 + 7] = a;
+    }
+  }
+
+  return 0; /*no error*/
+}
+
+/*put a pixel, given its RGBA16 color, into image of any color 16-bitdepth type*/
+static void rgba16ToPixel(unsigned char* out, size_t i,
+                         const LodePNGColorMode* mode,
+                         unsigned short r, unsigned short g, unsigned short b, unsigned short a)
+{
+  if(mode->colortype == LCT_GREY)
+  {
+    unsigned short grey = r; /*((unsigned)r + g + b) / 3*/;
+    out[i * 2 + 0] = (grey >> 8) & 255;
+    out[i * 2 + 1] = grey & 255;
+  }
+  else if(mode->colortype == LCT_RGB)
+  {
+    out[i * 6 + 0] = (r >> 8) & 255;
+    out[i * 6 + 1] = r & 255;
+    out[i * 6 + 2] = (g >> 8) & 255;
+    out[i * 6 + 3] = g & 255;
+    out[i * 6 + 4] = (b >> 8) & 255;
+    out[i * 6 + 5] = b & 255;
+  }
+  else if(mode->colortype == LCT_GREY_ALPHA)
+  {
+    unsigned short grey = r; /*((unsigned)r + g + b) / 3*/;
+    out[i * 4 + 0] = (grey >> 8) & 255;
+    out[i * 4 + 1] = grey & 255;
+    out[i * 4 + 2] = (a >> 8) & 255;
+    out[i * 4 + 3] = a & 255;
+  }
+  else if(mode->colortype == LCT_RGBA)
+  {
+    out[i * 8 + 0] = (r >> 8) & 255;
+    out[i * 8 + 1] = r & 255;
+    out[i * 8 + 2] = (g >> 8) & 255;
+    out[i * 8 + 3] = g & 255;
+    out[i * 8 + 4] = (b >> 8) & 255;
+    out[i * 8 + 5] = b & 255;
+    out[i * 8 + 6] = (a >> 8) & 255;
+    out[i * 8 + 7] = a & 255;
+  }
+}
+
+/*Get RGBA8 color of pixel with index i (y * width + x) from the raw image with given color type.*/
+static void getPixelColorRGBA8(unsigned char* r, unsigned char* g,
+                               unsigned char* b, unsigned char* a,
+                               const unsigned char* in, size_t i,
+                               const LodePNGColorMode* mode)
+{
+  if(mode->colortype == LCT_GREY)
+  {
+    if(mode->bitdepth == 8)
+    {
+      *r = *g = *b = in[i];
+      if(mode->key_defined && *r == mode->key_r) *a = 0;
+      else *a = 255;
+    }
+    else if(mode->bitdepth == 16)
+    {
+      *r = *g = *b = in[i * 2 + 0];
+      if(mode->key_defined && 256U * in[i * 2 + 0] + in[i * 2 + 1] == mode->key_r) *a = 0;
+      else *a = 255;
+    }
+    else
+    {
+      unsigned highest = ((1U << mode->bitdepth) - 1U); /*highest possible value for this bit depth*/
+      size_t j = i * mode->bitdepth;
+      unsigned value = readBitsFromReversedStream(&j, in, mode->bitdepth);
+      *r = *g = *b = (value * 255) / highest;
+      if(mode->key_defined && value == mode->key_r) *a = 0;
+      else *a = 255;
+    }
+  }
+  else if(mode->colortype == LCT_RGB)
+  {
+    if(mode->bitdepth == 8)
+    {
+      *r = in[i * 3 + 0]; *g = in[i * 3 + 1]; *b = in[i * 3 + 2];
+      if(mode->key_defined && *r == mode->key_r && *g == mode->key_g && *b == mode->key_b) *a = 0;
+      else *a = 255;
+    }
+    else
+    {
+      *r = in[i * 6 + 0];
+      *g = in[i * 6 + 2];
+      *b = in[i * 6 + 4];
+      if(mode->key_defined && 256U * in[i * 6 + 0] + in[i * 6 + 1] == mode->key_r
+         && 256U * in[i * 6 + 2] + in[i * 6 + 3] == mode->key_g
+         && 256U * in[i * 6 + 4] + in[i * 6 + 5] == mode->key_b) *a = 0;
+      else *a = 255;
+    }
+  }
+  else if(mode->colortype == LCT_PALETTE)
+  {
+    unsigned index;
+    if(mode->bitdepth == 8) index = in[i];
+    else
+    {
+      size_t j = i * mode->bitdepth;
+      index = readBitsFromReversedStream(&j, in, mode->bitdepth);
+    }
+
+    if(index >= mode->palettesize)
+    {
+      /*This is an error according to the PNG spec, but common PNG decoders make it black instead.
+      Done here too, slightly faster due to no error handling needed.*/
+      *r = *g = *b = 0;
+      *a = 255;
+    }
+    else
+    {
+      *r = mode->palette[index * 4 + 0];
+      *g = mode->palette[index * 4 + 1];
+      *b = mode->palette[index * 4 + 2];
+      *a = mode->palette[index * 4 + 3];
+    }
+  }
+  else if(mode->colortype == LCT_GREY_ALPHA)
+  {
+    if(mode->bitdepth == 8)
+    {
+      *r = *g = *b = in[i * 2 + 0];
+      *a = in[i * 2 + 1];
+    }
+    else
+    {
+      *r = *g = *b = in[i * 4 + 0];
+      *a = in[i * 4 + 2];
+    }
+  }
+  else if(mode->colortype == LCT_RGBA)
+  {
+    if(mode->bitdepth == 8)
+    {
+      *r = in[i * 4 + 0];
+      *g = in[i * 4 + 1];
+      *b = in[i * 4 + 2];
+      *a = in[i * 4 + 3];
+    }
+    else
+    {
+      *r = in[i * 8 + 0];
+      *g = in[i * 8 + 2];
+      *b = in[i * 8 + 4];
+      *a = in[i * 8 + 6];
+    }
+  }
+}
+
+/*Similar to getPixelColorRGBA8, but with all the for loops inside of the color
+mode test cases, optimized to convert the colors much faster, when converting
+to RGBA or RGB with 8 bit per cannel. buffer must be RGBA or RGB output with
+enough memory, if has_alpha is true the output is RGBA. mode has the color mode
+of the input buffer.*/
+static void getPixelColorsRGBA8(unsigned char* buffer, size_t numpixels,
+                                unsigned has_alpha, const unsigned char* in,
+                                const LodePNGColorMode* mode)
+{
+  unsigned num_channels = has_alpha ? 4 : 3;
+  size_t i;
+  if(mode->colortype == LCT_GREY)
+  {
+    if(mode->bitdepth == 8)
+    {
+      for(i = 0; i < numpixels; i++, buffer += num_channels)
+      {
+        buffer[0] = buffer[1] = buffer[2] = in[i];
+        if(has_alpha) buffer[3] = mode->key_defined && in[i] == mode->key_r ? 0 : 255;
+      }
+    }
+    else if(mode->bitdepth == 16)
+    {
+      for(i = 0; i < numpixels; i++, buffer += num_channels)
+      {
+        buffer[0] = buffer[1] = buffer[2] = in[i * 2];
+        if(has_alpha) buffer[3] = mode->key_defined && 256U * in[i * 2 + 0] + in[i * 2 + 1] == mode->key_r ? 0 : 255;
+      }
+    }
+    else
+    {
+      unsigned highest = ((1U << mode->bitdepth) - 1U); /*highest possible value for this bit depth*/
+      size_t j = 0;
+      for(i = 0; i < numpixels; i++, buffer += num_channels)
+      {
+        unsigned value = readBitsFromReversedStream(&j, in, mode->bitdepth);
+        buffer[0] = buffer[1] = buffer[2] = (value * 255) / highest;
+        if(has_alpha) buffer[3] = mode->key_defined && value == mode->key_r ? 0 : 255;
+      }
+    }
+  }
+  else if(mode->colortype == LCT_RGB)
+  {
+    if(mode->bitdepth == 8)
+    {
+      for(i = 0; i < numpixels; i++, buffer += num_channels)
+      {
+        buffer[0] = in[i * 3 + 0];
+        buffer[1] = in[i * 3 + 1];
+        buffer[2] = in[i * 3 + 2];
+        if(has_alpha) buffer[3] = mode->key_defined && buffer[0] == mode->key_r
+           && buffer[1]== mode->key_g && buffer[2] == mode->key_b ? 0 : 255;
+      }
+    }
+    else
+    {
+      for(i = 0; i < numpixels; i++, buffer += num_channels)
+      {
+        buffer[0] = in[i * 6 + 0];
+        buffer[1] = in[i * 6 + 2];
+        buffer[2] = in[i * 6 + 4];
+        if(has_alpha) buffer[3] = mode->key_defined
+           && 256U * in[i * 6 + 0] + in[i * 6 + 1] == mode->key_r
+           && 256U * in[i * 6 + 2] + in[i * 6 + 3] == mode->key_g
+           && 256U * in[i * 6 + 4] + in[i * 6 + 5] == mode->key_b ? 0 : 255;
+      }
+    }
+  }
+  else if(mode->colortype == LCT_PALETTE)
+  {
+    unsigned index;
+    size_t j = 0;
+    for(i = 0; i < numpixels; i++, buffer += num_channels)
+    {
+      if(mode->bitdepth == 8) index = in[i];
+      else index = readBitsFromReversedStream(&j, in, mode->bitdepth);
+
+      if(index >= mode->palettesize)
+      {
+        /*This is an error according to the PNG spec, but most PNG decoders make it black instead.
+        Done here too, slightly faster due to no error handling needed.*/
+        buffer[0] = buffer[1] = buffer[2] = 0;
+        if(has_alpha) buffer[3] = 255;
+      }
+      else
+      {
+        buffer[0] = mode->palette[index * 4 + 0];
+        buffer[1] = mode->palette[index * 4 + 1];
+        buffer[2] = mode->palette[index * 4 + 2];
+        if(has_alpha) buffer[3] = mode->palette[index * 4 + 3];
+      }
+    }
+  }
+  else if(mode->colortype == LCT_GREY_ALPHA)
+  {
+    if(mode->bitdepth == 8)
+    {
+      for(i = 0; i < numpixels; i++, buffer += num_channels)
+      {
+        buffer[0] = buffer[1] = buffer[2] = in[i * 2 + 0];
+        if(has_alpha) buffer[3] = in[i * 2 + 1];
+      }
+    }
+    else
+    {
+      for(i = 0; i < numpixels; i++, buffer += num_channels)
+      {
+        buffer[0] = buffer[1] = buffer[2] = in[i * 4 + 0];
+        if(has_alpha) buffer[3] = in[i * 4 + 2];
+      }
+    }
+  }
+  else if(mode->colortype == LCT_RGBA)
+  {
+    if(mode->bitdepth == 8)
+    {
+      for(i = 0; i < numpixels; i++, buffer += num_channels)
+      {
+        buffer[0] = in[i * 4 + 0];
+        buffer[1] = in[i * 4 + 1];
+        buffer[2] = in[i * 4 + 2];
+        if(has_alpha) buffer[3] = in[i * 4 + 3];
+      }
+    }
+    else
+    {
+      for(i = 0; i < numpixels; i++, buffer += num_channels)
+      {
+        buffer[0] = in[i * 8 + 0];
+        buffer[1] = in[i * 8 + 2];
+        buffer[2] = in[i * 8 + 4];
+        if(has_alpha) buffer[3] = in[i * 8 + 6];
+      }
+    }
+  }
+}
+
+/*Get RGBA16 color of pixel with index i (y * width + x) from the raw image with
+given color type, but the given color type must be 16-bit itself.*/
+static void getPixelColorRGBA16(unsigned short* r, unsigned short* g, unsigned short* b, unsigned short* a,
+                                const unsigned char* in, size_t i, const LodePNGColorMode* mode)
+{
+  if(mode->colortype == LCT_GREY)
+  {
+    *r = *g = *b = 256 * in[i * 2 + 0] + in[i * 2 + 1];
+    if(mode->key_defined && 256U * in[i * 2 + 0] + in[i * 2 + 1] == mode->key_r) *a = 0;
+    else *a = 65535;
+  }
+  else if(mode->colortype == LCT_RGB)
+  {
+    *r = 256 * in[i * 6 + 0] + in[i * 6 + 1];
+    *g = 256 * in[i * 6 + 2] + in[i * 6 + 3];
+    *b = 256 * in[i * 6 + 4] + in[i * 6 + 5];
+    if(mode->key_defined && 256U * in[i * 6 + 0] + in[i * 6 + 1] == mode->key_r
+       && 256U * in[i * 6 + 2] + in[i * 6 + 3] == mode->key_g
+       && 256U * in[i * 6 + 4] + in[i * 6 + 5] == mode->key_b) *a = 0;
+    else *a = 65535;
+  }
+  else if(mode->colortype == LCT_GREY_ALPHA)
+  {
+    *r = *g = *b = 256 * in[i * 4 + 0] + in[i * 4 + 1];
+    *a = 256 * in[i * 4 + 2] + in[i * 4 + 3];
+  }
+  else if(mode->colortype == LCT_RGBA)
+  {
+    *r = 256 * in[i * 8 + 0] + in[i * 8 + 1];
+    *g = 256 * in[i * 8 + 2] + in[i * 8 + 3];
+    *b = 256 * in[i * 8 + 4] + in[i * 8 + 5];
+    *a = 256 * in[i * 8 + 6] + in[i * 8 + 7];
+  }
+}
+
+unsigned lodepng_convert(unsigned char* out, const unsigned char* in,
+                         LodePNGColorMode* mode_out, const LodePNGColorMode* mode_in,
+                         unsigned w, unsigned h)
+{
+  size_t i;
+  ColorTree tree;
+  size_t numpixels = w * h;
+
+  if(lodepng_color_mode_equal(mode_out, mode_in))
+  {
+    size_t numbytes = lodepng_get_raw_size(w, h, mode_in);
+    for(i = 0; i < numbytes; i++) out[i] = in[i];
+    return 0;
+  }
+
+  if(mode_out->colortype == LCT_PALETTE)
+  {
+    size_t palsize = 1u << mode_out->bitdepth;
+    if(mode_out->palettesize < palsize) palsize = mode_out->palettesize;
+    color_tree_init(&tree);
+    for(i = 0; i < palsize; i++)
+    {
+      unsigned char* p = &mode_out->palette[i * 4];
+      color_tree_add(&tree, p[0], p[1], p[2], p[3], i);
+    }
+  }
+
+  if(mode_in->bitdepth == 16 && mode_out->bitdepth == 16)
+  {
+    for(i = 0; i < numpixels; i++)
+    {
+      unsigned short r = 0, g = 0, b = 0, a = 0;
+      getPixelColorRGBA16(&r, &g, &b, &a, in, i, mode_in);
+      rgba16ToPixel(out, i, mode_out, r, g, b, a);
+    }
+  }
+  else if(mode_out->bitdepth == 8 && mode_out->colortype == LCT_RGBA)
+  {
+    getPixelColorsRGBA8(out, numpixels, 1, in, mode_in);
+  }
+  else if(mode_out->bitdepth == 8 && mode_out->colortype == LCT_RGB)
+  {
+    getPixelColorsRGBA8(out, numpixels, 0, in, mode_in);
+  }
+  else
+  {
+    unsigned char r = 0, g = 0, b = 0, a = 0;
+    for(i = 0; i < numpixels; i++)
+    {
+      getPixelColorRGBA8(&r, &g, &b, &a, in, i, mode_in);
+      rgba8ToPixel(out, i, mode_out, &tree, r, g, b, a);
+    }
+  }
+
+  if(mode_out->colortype == LCT_PALETTE)
+  {
+    color_tree_cleanup(&tree);
+  }
+
+  return 0; /*no error (this function currently never has one, but maybe OOM detection added later.)*/
+}
+
+#ifdef LODEPNG_COMPILE_ENCODER
+
+void lodepng_color_profile_init(LodePNGColorProfile* profile)
+{
+  profile->colored = 0;
+  profile->key = 0;
+  profile->alpha = 0;
+  profile->key_r = profile->key_g = profile->key_b = 0;
+  profile->numcolors = 0;
+  profile->bits = 1;
+}
+
+/*function used for debug purposes with C++*/
+/*void printColorProfile(LodePNGColorProfile* p)
+{
+  std::cout << "colored: " << (int)p->colored << ", ";
+  std::cout << "key: " << (int)p->key << ", ";
+  std::cout << "key_r: " << (int)p->key_r << ", ";
+  std::cout << "key_g: " << (int)p->key_g << ", ";
+  std::cout << "key_b: " << (int)p->key_b << ", ";
+  std::cout << "alpha: " << (int)p->alpha << ", ";
+  std::cout << "numcolors: " << (int)p->numcolors << ", ";
+  std::cout << "bits: " << (int)p->bits << std::endl;
+}*/
+
+/*Returns how many bits needed to represent given value (max 8 bit)*/
+unsigned getValueRequiredBits(unsigned char value)
+{
+  if(value == 0 || value == 255) return 1;
+  /*The scaling of 2-bit and 4-bit values uses multiples of 85 and 17*/
+  if(value % 17 == 0) return value % 85 == 0 ? 2 : 4;
+  return 8;
+}
+
+/*profile must already have been inited with mode.
+It's ok to set some parameters of profile to done already.*/
+unsigned get_color_profile(LodePNGColorProfile* profile,
+                           const unsigned char* in, unsigned w, unsigned h,
+                           const LodePNGColorMode* mode)
+{
+  unsigned error = 0;
+  size_t i;
+  ColorTree tree;
+  size_t numpixels = w * h;
+
+  unsigned colored_done = lodepng_is_greyscale_type(mode) ? 1 : 0;
+  unsigned alpha_done = lodepng_can_have_alpha(mode) ? 0 : 1;
+  unsigned numcolors_done = 0;
+  unsigned bpp = lodepng_get_bpp(mode);
+  unsigned bits_done = bpp == 1 ? 1 : 0;
+  unsigned maxnumcolors = 257;
+  unsigned sixteen = 0;
+  if(bpp <= 8) maxnumcolors = bpp == 1 ? 2 : (bpp == 2 ? 4 : (bpp == 4 ? 16 : 256));
+
+  color_tree_init(&tree);
+
+  /*Check if the 16-bit input is truly 16-bit*/
+  if(mode->bitdepth == 16)
+  {
+    unsigned short r, g, b, a;
+    for(i = 0; i < numpixels; i++)
+    {
+      getPixelColorRGBA16(&r, &g, &b, &a, in, i, mode);
+      if(r % 257u != 0 || g % 257u != 0 || b % 257u != 0 || a % 257u != 0) /*first and second byte differ*/
+      {
+        sixteen = 1;
+        break;
+      }
+    }
+  }
+
+  if(sixteen)
+  {
+    unsigned short r = 0, g = 0, b = 0, a = 0;
+    profile->bits = 16;
+    bits_done = numcolors_done = 1; /*counting colors no longer useful, palette doesn't support 16-bit*/
+
+    for(i = 0; i < numpixels; i++)
+    {
+      getPixelColorRGBA16(&r, &g, &b, &a, in, i, mode);
+      
+      if(!colored_done && (r != g || r != b))
+      {
+        profile->colored = 1;
+        colored_done = 1;
+      }
+
+      if(!alpha_done)
+      {
+        unsigned matchkey = (r == profile->key_r && g == profile->key_g && b == profile->key_b);
+        if(a != 65535 && (a != 0 || (profile->key && !matchkey)))
+        {
+          profile->alpha = 1;
+          alpha_done = 1;
+          if(profile->bits < 8) profile->bits = 8; /*PNG has no alphachannel modes with less than 8-bit per channel*/
+        }
+        else if(a == 0 && !profile->alpha && !profile->key)
+        {
+          profile->key = 1;
+          profile->key_r = r;
+          profile->key_g = g;
+          profile->key_b = b;
+        }
+        else if(a == 65535 && profile->key && matchkey)
+        {
+          /* Color key cannot be used if an opaque pixel also has that RGB color. */
+          profile->alpha = 1;
+          alpha_done = 1;
+        }
+      }
+
+      if(alpha_done && numcolors_done && colored_done && bits_done) break;
+    }
+  }
+  else /* < 16-bit */
+  {
+    for(i = 0; i < numpixels; i++)
+    {
+      unsigned char r = 0, g = 0, b = 0, a = 0;
+      getPixelColorRGBA8(&r, &g, &b, &a, in, i, mode);
+
+      if(!bits_done && profile->bits < 8)
+      {
+        /*only r is checked, < 8 bits is only relevant for greyscale*/
+        unsigned bits = getValueRequiredBits(r);
+        if(bits > profile->bits) profile->bits = bits;
+      }
+      bits_done = (profile->bits >= bpp);
+
+      if(!colored_done && (r != g || r != b))
+      {
+        profile->colored = 1;
+        colored_done = 1;
+        if(profile->bits < 8) profile->bits = 8; /*PNG has no colored modes with less than 8-bit per channel*/
+      }
+
+      if(!alpha_done)
+      {
+        unsigned matchkey = (r == profile->key_r && g == profile->key_g && b == profile->key_b);
+        if(a != 255 && (a != 0 || (profile->key && !matchkey)))
+        {
+          profile->alpha = 1;
+          alpha_done = 1;
+          if(profile->bits < 8) profile->bits = 8; /*PNG has no alphachannel modes with less than 8-bit per channel*/
+        }
+        else if(a == 0 && !profile->alpha && !profile->key)
+        {
+          profile->key = 1;
+          profile->key_r = r;
+          profile->key_g = g;
+          profile->key_b = b;
+        }
+        else if(a == 255 && profile->key && matchkey)
+        {
+          /* Color key cannot be used if an opaque pixel also has that RGB color. */
+          profile->alpha = 1;
+          alpha_done = 1;
+          if(profile->bits < 8) profile->bits = 8; /*PNG has no alphachannel modes with less than 8-bit per channel*/
+        }
+      }
+
+      if(!numcolors_done)
+      {
+        if(!color_tree_has(&tree, r, g, b, a))
+        {
+          color_tree_add(&tree, r, g, b, a, profile->numcolors);
+          if(profile->numcolors < 256)
+          {
+            unsigned char* p = profile->palette;
+            unsigned n = profile->numcolors;
+            p[n * 4 + 0] = r;
+            p[n * 4 + 1] = g;
+            p[n * 4 + 2] = b;
+            p[n * 4 + 3] = a;
+          }
+          profile->numcolors++;
+          numcolors_done = profile->numcolors >= maxnumcolors;
+        }
+      }
+
+      if(alpha_done && numcolors_done && colored_done && bits_done) break;
+    }
+
+    /*make the profile's key always 16-bit for consistency - repeat each byte twice*/
+    profile->key_r *= 257;
+    profile->key_g *= 257;
+    profile->key_b *= 257;
+  }
+
+  color_tree_cleanup(&tree);
+  return error;
+}
+
+/*Automatically chooses color type that gives smallest amount of bits in the
+output image, e.g. grey if there are only greyscale pixels, palette if there
+are less than 256 colors, ...
+Updates values of mode with a potentially smaller color model. mode_out should
+contain the user chosen color model, but will be overwritten with the new chosen one.*/
+unsigned lodepng_auto_choose_color(LodePNGColorMode* mode_out,
+                                   const unsigned char* image, unsigned w, unsigned h,
+                                   const LodePNGColorMode* mode_in)
+{
+  LodePNGColorProfile prof;
+  unsigned error = 0;
+  unsigned i, n, palettebits, grey_ok, palette_ok;
+
+  lodepng_color_profile_init(&prof);
+  error = get_color_profile(&prof, image, w, h, mode_in);
+  if(error) return error;
+  mode_out->key_defined = 0;
+
+  if(prof.key && w * h <= 16) prof.alpha = 1; /*too few pixels to justify tRNS chunk overhead*/
+  grey_ok = !prof.colored && !prof.alpha; /*grey without alpha, with potentially low bits*/
+  n = prof.numcolors;
+  palettebits = n <= 2 ? 1 : (n <= 4 ? 2 : (n <= 16 ? 4 : 8));
+  palette_ok = n <= 256 && (n * 2 < w * h) && prof.bits <= 8;
+  if(w * h < n * 2) palette_ok = 0; /*don't add palette overhead if image has only a few pixels*/
+  if(grey_ok && prof.bits <= palettebits) palette_ok = 0; /*grey is less overhead*/
+
+  if(palette_ok)
+  {
+    unsigned char* p = prof.palette;
+    lodepng_palette_clear(mode_out); /*remove potential earlier palette*/
+    for(i = 0; i < prof.numcolors; i++)
+    {
+      error = lodepng_palette_add(mode_out, p[i * 4 + 0], p[i * 4 + 1], p[i * 4 + 2], p[i * 4 + 3]);
+      if(error) break;
+    }
+
+    mode_out->colortype = LCT_PALETTE;
+    mode_out->bitdepth = palettebits;
+
+    if(mode_in->colortype == LCT_PALETTE && mode_in->palettesize >= mode_out->palettesize
+        && mode_in->bitdepth == mode_out->bitdepth)
+    {
+      /*If input should have same palette colors, keep original to preserve its order and prevent conversion*/
+      lodepng_color_mode_cleanup(mode_out);
+      lodepng_color_mode_copy(mode_out, mode_in);
+    }
+  }
+  else /*8-bit or 16-bit per channel*/
+  {
+    mode_out->bitdepth = prof.bits;
+    mode_out->colortype = prof.alpha ? (prof.colored ? LCT_RGBA : LCT_GREY_ALPHA)
+                                     : (prof.colored ? LCT_RGB : LCT_GREY);
+
+    if(prof.key && !prof.alpha)
+    {
+      unsigned mask = (1u << mode_out->bitdepth) - 1u; /*profile always uses 16-bit, mask converts it*/
+      mode_out->key_r = prof.key_r & mask;
+      mode_out->key_g = prof.key_g & mask;
+      mode_out->key_b = prof.key_b & mask;
+      mode_out->key_defined = 1;
+    }
+  }
+
+  return error;
+}
+
+#endif /* #ifdef LODEPNG_COMPILE_ENCODER */
+
+/*
+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);
+
+  if(pc < pa && pc < pb) return (unsigned char)c;
+  else if(pb < pa) return (unsigned char)b;
+  else return (unsigned char)a;
+}
+
+/*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*/
+
+/*
+Outputs various dimensions and positions in the image related to the Adam7 reduced images.
+passw: output containing the width of the 7 passes
+passh: output containing the height of the 7 passes
+filter_passstart: output containing the index of the start and end of each
+ reduced image with filter bytes
+padded_passstart output containing the index of the start and end of each
+ reduced image when without filter bytes but with padded scanlines
+passstart: output containing the index of the start and end of each reduced
+ image without padding between scanlines, but still padding between the images
+w, h: width and height of non-interlaced image
+bpp: bits per pixel
+"padded" is only relevant if bpp is less than 8 and a scanline or image does not
+ end at a full byte
+*/
+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 LodePNGInfo. return value is error*/
+unsigned lodepng_inspect(unsigned* w, unsigned* h, LodePNGState* state,
+                         const unsigned char* in, size_t insize)
+{
+  LodePNGInfo* info = &state->info_png;
+  if(insize == 0 || in == 0)
+  {
+    CERROR_RETURN_ERROR(state->error, 48); /*error: the given data is empty*/
+  }
+  if(insize < 29)
+  {
+    CERROR_RETURN_ERROR(state->error, 27); /*error: the data length is smaller than the length of a PNG header*/
+  }
+
+  /*when decoding a new PNG image, make sure all parameters created after previous decoding are reset*/
+  lodepng_info_cleanup(info);
+  lodepng_info_init(info);
+
+  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)
+  {
+    CERROR_RETURN_ERROR(state->error, 28); /*error: the first 8 bytes are not the correct PNG signature*/
+  }
+  if(in[12] != 'I' || in[13] != 'H' || in[14] != 'D' || in[15] != 'R')
+  {
+    CERROR_RETURN_ERROR(state->error, 29); /*error: it doesn't start with a IHDR chunk!*/
+  }
+
+  /*read the values given in the header*/
+  *w = lodepng_read32bitInt(&in[16]);
+  *h = lodepng_read32bitInt(&in[20]);
+  info->color.bitdepth = in[24];
+  info->color.colortype = (LodePNGColorType)in[25];
+  info->compression_method = in[26];
+  info->filter_method = in[27];
+  info->interlace_method = in[28];
+
+  if(!state->decoder.ignore_crc)
+  {
+    unsigned CRC = lodepng_read32bitInt(&in[29]);
+    unsigned checksum = lodepng_crc32(&in[12], 17);
+    if(CRC != checksum)
+    {
+      CERROR_RETURN_ERROR(state->error, 57); /*invalid CRC*/
+    }
+  }
+
+  /*error: only compression method 0 is allowed in the specification*/
+  if(info->compression_method != 0) CERROR_RETURN_ERROR(state->error, 32);
+  /*error: only filter method 0 is allowed in the specification*/
+  if(info->filter_method != 0) CERROR_RETURN_ERROR(state->error, 33);
+  /*error: only interlace methods 0 and 1 exist in the specification*/
+  if(info->interlace_method > 1) CERROR_RETURN_ERROR(state->error, 34);
+
+  state->error = checkColorValidity(info->color.colortype, info->color.bitdepth);
+  return state->error;
+}
+
+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];
+
+    CERROR_TRY_RETURN(unfilterScanline(&out[outindex], &in[inindex + 1], prevline, bytewidth, filterType, linebytes));
+
+    prevline = &out[outindex];
+  }
+
+  return 0;
+}
+
+/*
+in: Adam7 interlaced image, with no padding bits between scanlines, but between
+ reduced images so that each reduced image starts at a byte.
+out: the same pixels, but re-ordered so that they're now a non-interlaced image with size w*h
+bpp: bits per pixel
+out has the following size in bits: w * h * bpp.
+in is possibly bigger due to padding bits between reduced images.
+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)
+NOTE: comments about padding bits are only relevant if bpp < 8
+*/
+static void Adam7_deinterlace(unsigned char* out, const unsigned char* in, unsigned w, unsigned h, unsigned bpp)
+{
+  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,
+                                     unsigned w, unsigned h, const LodePNGInfo* info_png)
+{
+  /*
+  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_get_bpp(&info_png->color);
+  if(bpp == 0) return 31; /*error: invalid colortype*/
+
+  if(info_png->interlace_method == 0)
+  {
+    if(bpp < 8 && w * bpp != ((w * bpp + 7) / 8) * 8)
+    {
+      CERROR_TRY_RETURN(unfilter(in, in, w, h, bpp));
+      removePaddingBits(out, in, w * bpp, ((w * bpp + 7) / 8) * 8, h);
+    }
+    /*we can immediatly filter into the out buffer, no other steps needed*/
+    else CERROR_TRY_RETURN(unfilter(out, in, w, h, bpp));
+  }
+  else /*interlace_method 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++)
+    {
+      CERROR_TRY_RETURN(unfilter(&in[padded_passstart[i]], &in[filter_passstart[i]], passw[i], passh[i], bpp));
+      /*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 0;
+}
+
+static unsigned readChunk_PLTE(LodePNGColorMode* color, const unsigned char* data, size_t chunkLength)
+{
+  unsigned pos = 0, i;
+  if(color->palette) lodepng_free(color->palette);
+  color->palettesize = chunkLength / 3;
+  color->palette = (unsigned char*)lodepng_malloc(4 * color->palettesize);
+  if(!color->palette && color->palettesize)
+  {
+    color->palettesize = 0;
+    return 83; /*alloc fail*/
+  }
+  if(color->palettesize > 256) return 38; /*error: palette too big*/
+
+  for(i = 0; i < color->palettesize; i++)
+  {
+    color->palette[4 * i + 0] = data[pos++]; /*R*/
+    color->palette[4 * i + 1] = data[pos++]; /*G*/
+    color->palette[4 * i + 2] = data[pos++]; /*B*/
+    color->palette[4 * i + 3] = 255; /*alpha*/
+  }
+
+  return 0; /* OK */
+}
+
+static unsigned readChunk_tRNS(LodePNGColorMode* color, const unsigned char* data, size_t chunkLength)
+{
+  unsigned i;
+  if(color->colortype == LCT_PALETTE)
+  {
+    /*error: more alpha values given than there are palette entries*/
+    if(chunkLength > color->palettesize) return 38;
+
+    for(i = 0; i < chunkLength; i++) color->palette[4 * i + 3] = data[i];
+  }
+  else if(color->colortype == LCT_GREY)
+  {
+    /*error: this chunk must be 2 bytes for greyscale image*/
+    if(chunkLength != 2) return 30;
+
+    color->key_defined = 1;
+    color->key_r = color->key_g = color->key_b = 256u * data[0] + data[1];
+  }
+  else if(color->colortype == LCT_RGB)
+  {
+    /*error: this chunk must be 6 bytes for RGB image*/
+    if(chunkLength != 6) return 41;
+
+    color->key_defined = 1;
+    color->key_r = 256u * data[0] + data[1];
+    color->key_g = 256u * data[2] + data[3];
+    color->key_b = 256u * data[4] + data[5];
+  }
+  else return 42; /*error: tRNS chunk not allowed for other color models*/
+
+  return 0; /* OK */
+}
+
+
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+/*background color chunk (bKGD)*/
+static unsigned readChunk_bKGD(LodePNGInfo* info, const unsigned char* data, size_t chunkLength)
+{
+  if(info->color.colortype == LCT_PALETTE)
+  {
+    /*error: this chunk must be 1 byte for indexed color image*/
+    if(chunkLength != 1) return 43;
+
+    info->background_defined = 1;
+    info->background_r = info->background_g = info->background_b = data[0];
+  }
+  else if(info->color.colortype == LCT_GREY || info->color.colortype == LCT_GREY_ALPHA)
+  {
+    /*error: this chunk must be 2 bytes for greyscale image*/
+    if(chunkLength != 2) return 44;
+
+    info->background_defined = 1;
+    info->background_r = info->background_g = info->background_b = 256u * data[0] + data[1];
+  }
+  else if(info->color.colortype == LCT_RGB || info->color.colortype == LCT_RGBA)
+  {
+    /*error: this chunk must be 6 bytes for greyscale image*/
+    if(chunkLength != 6) return 45;
+
+    info->background_defined = 1;
+    info->background_r = 256u * data[0] + data[1];
+    info->background_g = 256u * data[2] + data[3];
+    info->background_b = 256u * data[4] + data[5];
+  }
+
+  return 0; /* OK */
+}
+
+/*text chunk (tEXt)*/
+static unsigned readChunk_tEXt(LodePNGInfo* info, const unsigned char* data, size_t chunkLength)
+{
+  unsigned error = 0;
+  char *key = 0, *str = 0;
+  unsigned i;
+
+  while(!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++;
+    /*even though it's not allowed by the standard, no error is thrown if
+    there's no null termination char, if the text is empty*/
+    if(length < 1 || length > 79) CERROR_BREAK(error, 89); /*keyword too short or long*/
+
+    key = (char*)lodepng_malloc(length + 1);
+    if(!key) CERROR_BREAK(error, 83); /*alloc fail*/
+
+    key[length] = 0;
+    for(i = 0; i < length; i++) key[i] = (char)data[i];
+
+    string2_begin = length + 1; /*skip keyword null terminator*/
+
+    length = chunkLength < string2_begin ? 0 : chunkLength - string2_begin;
+    str = (char*)lodepng_malloc(length + 1);
+    if(!str) CERROR_BREAK(error, 83); /*alloc fail*/
+
+    str[length] = 0;
+    for(i = 0; i < length; i++) str[i] = (char)data[string2_begin + i];
+
+    error = lodepng_add_text(info, key, str);
+
+    break;
+  }
+
+  lodepng_free(key);
+  lodepng_free(str);
+
+  return error;
+}
+
+/*compressed text chunk (zTXt)*/
+static unsigned readChunk_zTXt(LodePNGInfo* info, const LodePNGDecompressSettings* zlibsettings,
+                               const unsigned char* data, size_t chunkLength)
+{
+  unsigned error = 0;
+  unsigned i;
+
+  unsigned length, string2_begin;
+  char *key = 0;
+  ucvector decoded;
+
+  ucvector_init(&decoded);
+
+  while(!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(error, 75); /*no null termination, corrupt?*/
+    if(length < 1 || length > 79) CERROR_BREAK(error, 89); /*keyword too short or long*/
+
+    key = (char*)lodepng_malloc(length + 1);
+    if(!key) CERROR_BREAK(error, 83); /*alloc fail*/
+
+    key[length] = 0;
+    for(i = 0; i < length; i++) key[i] = (char)data[i];
+
+    if(data[length + 1] != 0) CERROR_BREAK(error, 72); /*the 0 byte indicating compression must be 0*/
+
+    string2_begin = length + 2;
+    if(string2_begin > chunkLength) CERROR_BREAK(error, 75); /*no null termination, corrupt?*/
+
+    length = chunkLength - string2_begin;
+    /*will fail if zlib error, e.g. if length is too small*/
+    error = zlib_decompress(&decoded.data, &decoded.size,
+                            (unsigned char*)(&data[string2_begin]),
+                            length, zlibsettings);
+    if(error) break;
+    ucvector_push_back(&decoded, 0);
+
+    error = lodepng_add_text(info, key, (char*)decoded.data);
+
+    break;
+  }
+
+  lodepng_free(key);
+  ucvector_cleanup(&decoded);
+
+  return error;
+}
+
+/*international text chunk (iTXt)*/
+static unsigned readChunk_iTXt(LodePNGInfo* info, const LodePNGDecompressSettings* zlibsettings,
+                               const unsigned char* data, size_t chunkLength)
+{
+  unsigned error = 0;
+  unsigned i;
+
+  unsigned length, begin, compressed;
+  char *key = 0, *langtag = 0, *transkey = 0;
+  ucvector decoded;
+  ucvector_init(&decoded);
+
+  while(!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(error, 30); /*iTXt chunk too short*/
+
+    /*read the key*/
+    for(length = 0; length < chunkLength && data[length] != 0; length++) ;
+    if(length + 3 >= chunkLength) CERROR_BREAK(error, 75); /*no null termination char, corrupt?*/
+    if(length < 1 || length > 79) CERROR_BREAK(error, 89); /*keyword too short or long*/
+
+    key = (char*)lodepng_malloc(length + 1);
+    if(!key) CERROR_BREAK(error, 83); /*alloc fail*/
+
+    key[length] = 0;
+    for(i = 0; i < length; i++) key[i] = (char)data[i];
+
+    /*read the compression method*/
+    compressed = data[length + 1];
+    if(data[length + 2] != 0) CERROR_BREAK(error, 72); /*the 0 byte indicating compression must be 0*/
+
+    /*even though it's not allowed by the standard, no error is thrown if
+    there's no null termination char, if the text is empty for the next 3 texts*/
+
+    /*read the langtag*/
+    begin = length + 3;
+    length = 0;
+    for(i = begin; i < chunkLength && data[i] != 0; i++) length++;
+
+    langtag = (char*)lodepng_malloc(length + 1);
+    if(!langtag) CERROR_BREAK(error, 83); /*alloc fail*/
+
+    langtag[length] = 0;
+    for(i = 0; i < length; i++) langtag[i] = (char)data[begin + i];
+
+    /*read the transkey*/
+    begin += length + 1;
+    length = 0;
+    for(i = begin; i < chunkLength && data[i] != 0; i++) length++;
+
+    transkey = (char*)lodepng_malloc(length + 1);
+    if(!transkey) CERROR_BREAK(error, 83); /*alloc fail*/
+
+    transkey[length] = 0;
+    for(i = 0; i < length; i++) transkey[i] = (char)data[begin + i];
+
+    /*read the actual text*/
+    begin += length + 1;
+
+    length = chunkLength < begin ? 0 : chunkLength - begin;
+
+    if(compressed)
+    {
+      /*will fail if zlib error, e.g. if length is too small*/
+      error = zlib_decompress(&decoded.data, &decoded.size,
+                              (unsigned char*)(&data[begin]),
+                              length, zlibsettings);
+      if(error) break;
+      if(decoded.allocsize < decoded.size) decoded.allocsize = decoded.size;
+      ucvector_push_back(&decoded, 0);
+    }
+    else
+    {
+      if(!ucvector_resize(&decoded, length + 1)) CERROR_BREAK(error, 83 /*alloc fail*/);
+
+      decoded.data[length] = 0;
+      for(i = 0; i < length; i++) decoded.data[i] = data[begin + i];
+    }
+
+    error = lodepng_add_itext(info, key, langtag, transkey, (char*)decoded.data);
+
+    break;
+  }
+
+  lodepng_free(key);
+  lodepng_free(langtag);
+  lodepng_free(transkey);
+  ucvector_cleanup(&decoded);
+
+  return error;
+}
+
+static unsigned readChunk_tIME(LodePNGInfo* info, const unsigned char* data, size_t chunkLength)
+{
+  if(chunkLength != 7) return 73; /*invalid tIME chunk size*/
+
+  info->time_defined = 1;
+  info->time.year = 256u * data[0] + data[1];
+  info->time.month = data[2];
+  info->time.day = data[3];
+  info->time.hour = data[4];
+  info->time.minute = data[5];
+  info->time.second = data[6];
+
+  return 0; /* OK */
+}
+
+static unsigned readChunk_pHYs(LodePNGInfo* info, const unsigned char* data, size_t chunkLength)
+{
+  if(chunkLength != 9) return 74; /*invalid pHYs chunk size*/
+
+  info->phys_defined = 1;
+  info->phys_x = 16777216u * data[0] + 65536u * data[1] + 256u * data[2] + data[3];
+  info->phys_y = 16777216u * data[4] + 65536u * data[5] + 256u * data[6] + data[7];
+  info->phys_unit = data[8];
+
+  return 0; /* OK */
+}
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+
+/*read a PNG, the result will be in the same color type as the PNG (hence "generic")*/
+static void decodeGeneric(unsigned char** out, unsigned* w, unsigned* h,
+                          LodePNGState* state,
+                          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*/
+  ucvector scanlines;
+  size_t predict;
+
+  /*for unknown chunk order*/
+  unsigned unknown = 0;
+#ifdef LODEPNG_COMPILE_ANCILLARY_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;
+
+  state->error = lodepng_inspect(w, h, state, in, insize); /*reads header and resets other parameters in state->info_png*/
+  if(state->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 && !state->error)
+  {
+    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(state->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(state->error, 63);
+
+    if((size_t)((chunk - in) + chunkLength + 12) > insize || (chunk + chunkLength + 12) < in)
+    {
+      CERROR_BREAK(state->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(state->error, 83 /*alloc fail*/);
+      for(i = 0; i < chunkLength; i++) idat.data[oldsize + i] = data[i];
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+      critical_pos = 3;
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+    }
+    /*IEND chunk*/
+    else if(lodepng_chunk_type_equals(chunk, "IEND"))
+    {
+      IEND = 1;
+    }
+    /*palette chunk (PLTE)*/
+    else if(lodepng_chunk_type_equals(chunk, "PLTE"))
+    {
+      state->error = readChunk_PLTE(&state->info_png.color, data, chunkLength);
+      if(state->error) break;
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+      critical_pos = 2;
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+    }
+    /*palette transparency chunk (tRNS)*/
+    else if(lodepng_chunk_type_equals(chunk, "tRNS"))
+    {
+      state->error = readChunk_tRNS(&state->info_png.color, data, chunkLength);
+      if(state->error) break;
+    }
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+    /*background color chunk (bKGD)*/
+    else if(lodepng_chunk_type_equals(chunk, "bKGD"))
+    {
+      state->error = readChunk_bKGD(&state->info_png, data, chunkLength);
+      if(state->error) break;
+    }
+    /*text chunk (tEXt)*/
+    else if(lodepng_chunk_type_equals(chunk, "tEXt"))
+    {
+      if(state->decoder.read_text_chunks)
+      {
+        state->error = readChunk_tEXt(&state->info_png, data, chunkLength);
+        if(state->error) break;
+      }
+    }
+    /*compressed text chunk (zTXt)*/
+    else if(lodepng_chunk_type_equals(chunk, "zTXt"))
+    {
+      if(state->decoder.read_text_chunks)
+      {
+        state->error = readChunk_zTXt(&state->info_png, &state->decoder.zlibsettings, data, chunkLength);
+        if(state->error) break;
+      }
+    }
+    /*international text chunk (iTXt)*/
+    else if(lodepng_chunk_type_equals(chunk, "iTXt"))
+    {
+      if(state->decoder.read_text_chunks)
+      {
+        state->error = readChunk_iTXt(&state->info_png, &state->decoder.zlibsettings, data, chunkLength);
+        if(state->error) break;
+      }
+    }
+    else if(lodepng_chunk_type_equals(chunk, "tIME"))
+    {
+      state->error = readChunk_tIME(&state->info_png, data, chunkLength);
+      if(state->error) break;
+    }
+    else if(lodepng_chunk_type_equals(chunk, "pHYs"))
+    {
+      state->error = readChunk_pHYs(&state->info_png, data, chunkLength);
+      if(state->error) break;
+    }
+#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_ancillary(chunk)) CERROR_BREAK(state->error, 69);
+
+      unknown = 1;
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+      if(state->decoder.remember_unknown_chunks)
+      {
+        state->error = lodepng_chunk_append(&state->info_png.unknown_chunks_data[critical_pos - 1],
+                                            &state->info_png.unknown_chunks_size[critical_pos - 1], chunk);
+        if(state->error) break;
+      }
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+    }
+
+    if(!state->decoder.ignore_crc && !unknown) /*check CRC if wanted, only on known chunk types*/
+    {
+      if(lodepng_chunk_check_crc(chunk)) CERROR_BREAK(state->error, 57); /*invalid CRC*/
+    }
+
+    if(!IEND) chunk = lodepng_chunk_next_const(chunk);
+  }
+
+  ucvector_init(&scanlines);
+  /*predict output size, to allocate exact size for output buffer to avoid more dynamic allocation.
+  The prediction is currently not correct for interlaced PNG images.*/
+  predict = lodepng_get_raw_size_idat(*w, *h, &state->info_png.color) + *h;
+  if(!state->error && !ucvector_reserve(&scanlines, predict)) state->error = 83; /*alloc fail*/
+  if(!state->error)
+  {
+    state->error = zlib_decompress(&scanlines.data, &scanlines.size, idat.data,
+                                   idat.size, &state->decoder.zlibsettings);
+  }
+  ucvector_cleanup(&idat);
+
+  if(!state->error)
+  {
+    ucvector outv;
+    ucvector_init(&outv);
+    if(!ucvector_resizev(&outv,
+        lodepng_get_raw_size(*w, *h, &state->info_png.color), 0)) state->error = 83; /*alloc fail*/
+    if(!state->error) state->error = postProcessScanlines(outv.data, scanlines.data, *w, *h, &state->info_png);
+    *out = outv.data;
+  }
+  ucvector_cleanup(&scanlines);
+}
+
+unsigned lodepng_decode(unsigned char** out, unsigned* w, unsigned* h,
+                        LodePNGState* state,
+                        const unsigned char* in, size_t insize)
+{
+  *out = 0;
+  decodeGeneric(out, w, h, state, in, insize);
+  if(state->error) return state->error;
+  if(!state->decoder.color_convert || lodepng_color_mode_equal(&state->info_raw, &state->info_png.color))
+  {
+    /*same color type, no copying or converting of data needed*/
+    /*store the info_png color settings on the info_raw so that the info_raw still reflects what colortype
+    the raw image has to the end user*/
+    if(!state->decoder.color_convert)
+    {
+      state->error = lodepng_color_mode_copy(&state->info_raw, &state->info_png.color);
+      if(state->error) return state->error;
+    }
+  }
+  else
+  {
+    /*color conversion needed; sort of copy of the data*/
+    unsigned char* data = *out;
+    size_t outsize;
+
+    /*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(!(state->info_raw.colortype == LCT_RGB || state->info_raw.colortype == LCT_RGBA)
+       && !(state->info_raw.bitdepth == 8))
+    {
+      return 56; /*unsupported color mode conversion*/
+    }
+
+    outsize = lodepng_get_raw_size(*w, *h, &state->info_raw);
+    *out = (unsigned char*)lodepng_malloc(outsize);
+    if(!(*out))
+    {
+      state->error = 83; /*alloc fail*/
+    }
+    else state->error = lodepng_convert(*out, data, &state->info_raw,
+                                        &state->info_png.color, *w, *h);
+    lodepng_free(data);
+  }
+  return state->error;
+}
+
+unsigned lodepng_decode_memory(unsigned char** out, unsigned* w, unsigned* h, const unsigned char* in,
+                               size_t insize, LodePNGColorType colortype, unsigned bitdepth)
+{
+  unsigned error;
+  LodePNGState state;
+  lodepng_state_init(&state);
+  state.info_raw.colortype = colortype;
+  state.info_raw.bitdepth = bitdepth;
+  error = lodepng_decode(out, w, h, &state, in, insize);
+  lodepng_state_cleanup(&state);
+  return error;
+}
+
+unsigned lodepng_decode32(unsigned char** out, unsigned* w, unsigned* h, const unsigned char* in, size_t insize)
+{
+  return lodepng_decode_memory(out, w, h, in, insize, LCT_RGBA, 8);
+}
+
+unsigned lodepng_decode24(unsigned char** out, unsigned* w, unsigned* h, const unsigned char* in, size_t insize)
+{
+  return lodepng_decode_memory(out, w, h, in, insize, LCT_RGB, 8);
+}
+
+#ifdef LODEPNG_COMPILE_DISK
+unsigned lodepng_decode_file(unsigned char** out, unsigned* w, unsigned* h, const char* filename,
+                             LodePNGColorType colortype, unsigned bitdepth)
+{
+  unsigned char* buffer;
+  size_t buffersize;
+  unsigned error;
+  error = lodepng_load_file(&buffer, &buffersize, filename);
+  if(!error) error = lodepng_decode_memory(out, w, h, buffer, buffersize, colortype, bitdepth);
+  lodepng_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, LCT_RGBA, 8);
+}
+
+unsigned lodepng_decode24_file(unsigned char** out, unsigned* w, unsigned* h, const char* filename)
+{
+  return lodepng_decode_file(out, w, h, filename, LCT_RGB, 8);
+}
+#endif /*LODEPNG_COMPILE_DISK*/
+
+void lodepng_decoder_settings_init(LodePNGDecoderSettings* settings)
+{
+  settings->color_convert = 1;
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+  settings->read_text_chunks = 1;
+  settings->remember_unknown_chunks = 0;
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+  settings->ignore_crc = 0;
+  lodepng_decompress_settings_init(&settings->zlibsettings);
+}
+
+#endif /*LODEPNG_COMPILE_DECODER*/
+
+#if defined(LODEPNG_COMPILE_DECODER) || defined(LODEPNG_COMPILE_ENCODER)
+
+void lodepng_state_init(LodePNGState* state)
+{
+#ifdef LODEPNG_COMPILE_DECODER
+  lodepng_decoder_settings_init(&state->decoder);
+#endif /*LODEPNG_COMPILE_DECODER*/
+#ifdef LODEPNG_COMPILE_ENCODER
+  lodepng_encoder_settings_init(&state->encoder);
+#endif /*LODEPNG_COMPILE_ENCODER*/
+  lodepng_color_mode_init(&state->info_raw);
+  lodepng_info_init(&state->info_png);
+  state->error = 1;
+}
+
+void lodepng_state_cleanup(LodePNGState* state)
+{
+  lodepng_color_mode_cleanup(&state->info_raw);
+  lodepng_info_cleanup(&state->info_png);
+}
+
+void lodepng_state_copy(LodePNGState* dest, const LodePNGState* source)
+{
+  lodepng_state_cleanup(dest);
+  *dest = *source;
+  lodepng_color_mode_init(&dest->info_raw);
+  lodepng_info_init(&dest->info_png);
+  dest->error = lodepng_color_mode_copy(&dest->info_raw, &source->info_raw); if(dest->error) return;
+  dest->error = lodepng_info_copy(&dest->info_png, &source->info_png); if(dest->error) return;
+}
+
+#endif /* defined(LODEPNG_COMPILE_DECODER) || defined(LODEPNG_COMPILE_ENCODER) */
+
+#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)
+{
+  CERROR_TRY_RETURN(lodepng_chunk_create(&out->data, &out->size, (unsigned)length, chunkName, data));
+  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,
+                              LodePNGColorType colortype, unsigned bitdepth, unsigned interlace_method)
+{
+  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, interlace_method); /*interlace method*/
+
+  error = addChunk(out, "IHDR", header.data, header.size);
+  ucvector_cleanup(&header);
+
+  return error;
+}
+
+static unsigned addChunk_PLTE(ucvector* out, const LodePNGColorMode* 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 LodePNGColorMode* info)
+{
+  unsigned error = 0;
+  size_t i;
+  ucvector tRNS;
+  ucvector_init(&tRNS);
+  if(info->colortype == LCT_PALETTE)
+  {
+    size_t amount = info->palettesize;
+    /*the tail of palette values that all have 255 as alpha, does not have to be encoded*/
+    for(i = info->palettesize; i > 0; i--)
+    {
+      if(info->palette[4 * (i - 1) + 3] == 255) amount--;
+      else break;
+    }
+    /*add only alpha channel*/
+    for(i = 0; i < amount; i++) ucvector_push_back(&tRNS, info->palette[4 * i + 3]);
+  }
+  else if(info->colortype == LCT_GREY)
+  {
+    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 == LCT_RGB)
+  {
+    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,
+                              LodePNGCompressSettings* zlibsettings)
+{
+  ucvector zlibdata;
+  unsigned error = 0;
+
+  /*compress with the Zlib compressor*/
+  ucvector_init(&zlibdata);
+  error = 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]);
+  if(i < 1 || i > 79) return 89; /*error: invalid keyword size*/
+  ucvector_push_back(&text, 0); /*0 termination char*/
+  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,
+                              LodePNGCompressSettings* 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]);
+  if(i < 1 || i > 79) return 89; /*error: invalid keyword size*/
+  ucvector_push_back(&data, 0); /*0 termination char*/
+  ucvector_push_back(&data, 0); /*compression method: 0*/
+
+  error = 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, LodePNGCompressSettings* zlibsettings)
+{
+  unsigned error = 0;
+  ucvector 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]);
+  if(i < 1 || i > 79) return 89; /*error: invalid keyword size*/
+  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 compressed_data;
+    ucvector_init(&compressed_data);
+    error = 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]);
+    }
+    ucvector_cleanup(&compressed_data);
+  }
+  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 LodePNGInfo* info)
+{
+  unsigned error = 0;
+  ucvector bKGD;
+  ucvector_init(&bKGD);
+  if(info->color.colortype == LCT_GREY || info->color.colortype == LCT_GREY_ALPHA)
+  {
+    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 == LCT_RGB || info->color.colortype == LCT_RGBA)
+  {
+    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 == LCT_PALETTE)
+  {
+    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 LodePNGTime* time)
+{
+  unsigned error = 0;
+  unsigned char* data = (unsigned char*)lodepng_malloc(7);
+  if(!data) return 83; /*alloc fail*/
+  data[0] = (unsigned char)(time->year / 256);
+  data[1] = (unsigned char)(time->year % 256);
+  data[2] = (unsigned char)time->month;
+  data[3] = (unsigned char)time->day;
+  data[4] = (unsigned char)time->hour;
+  data[5] = (unsigned char)time->minute;
+  data[6] = (unsigned char)time->second;
+  error = addChunk(out, "tIME", data, 7);
+  lodepng_free(data);
+  return error;
+}
+
+static unsigned addChunk_pHYs(ucvector* out, const LodePNGInfo* 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*/
+  }
+}
+
+/* log2 approximation. A slight bit faster than std::log. */
+static float flog2(float f)
+{
+  float result = 0;
+  while(f > 32) { result += 4; f /= 16; }
+  while(f > 2) { result++; f /= 2; }
+  return result + 1.442695f * (f * f * f / 3 - 3 * f * f / 2 + 3 * f - 1.83333f);
+}
+
+static unsigned filter(unsigned char* out, const unsigned char* in, unsigned w, unsigned h,
+                       const LodePNGColorMode* info, const LodePNGEncoderSettings* 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_get_bpp(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;
+  LodePNGFilterStrategy strategy = settings->filter_strategy;
+
+  /*
+  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.
+  This heuristic is used if filter strategy is LFS_MINSUM and filter_palette_zero is true.
+
+  If filter_palette_zero is true and filter_strategy is not LFS_MINSUM, the above heuristic is followed,
+  but for "the other case", whatever strategy filter_strategy is set to instead of the minimum sum
+  heuristic is used.
+  */
+  if(settings->filter_palette_zero &&
+     (info->colortype == LCT_PALETTE || info->bitdepth < 8)) strategy = LFS_ZERO;
+
+  if(bpp == 0) return 31; /*error: invalid color type*/
+
+  if(strategy == LFS_ZERO)
+  {
+    for(y = 0; y < h; y++)
+    {
+      size_t outindex = (1 + linebytes) * y; /*the extra filterbyte added to each row*/
+      size_t inindex = linebytes * y;
+      out[outindex] = 0; /*filter type byte*/
+      filterScanline(&out[outindex + 1], &in[inindex], prevline, linebytes, bytewidth, 0);
+      prevline = &in[inindex];
+    }
+  }
+  else if(strategy == LFS_MINSUM)
+  {
+    /*adaptive filtering*/
+    size_t sum[5];
+    ucvector attempt[5]; /*five filtering attempts, one for each filter type*/
+    size_t smallest = 0;
+    unsigned char type, bestType = 0;
+
+    for(type = 0; type < 5; type++)
+    {
+      ucvector_init(&attempt[type]);
+      if(!ucvector_resize(&attempt[type], linebytes)) return 83; /*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;
+          if(type == 0)
+          {
+            for(x = 0; x < linebytes; x++) sum[type] += (unsigned char)(attempt[type].data[x]);
+          }
+          else
+          {
+            for(x = 0; x < linebytes; x++)
+            {
+              /*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.*/
+              unsigned char s = attempt[type].data[x];
+              sum[type] += s < 128 ? s : (255U - 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 if(strategy == LFS_ENTROPY)
+  {
+    float sum[5];
+    ucvector attempt[5]; /*five filtering attempts, one for each filter type*/
+    float smallest = 0;
+    unsigned type, bestType = 0;
+    unsigned count[256];
+
+    for(type = 0; type < 5; type++)
+    {
+      ucvector_init(&attempt[type]);
+      if(!ucvector_resize(&attempt[type], linebytes)) return 83; /*alloc fail*/
+    }
+
+    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);
+        for(x = 0; x < 256; x++) count[x] = 0;
+        for(x = 0; x < linebytes; x++) count[attempt[type].data[x]]++;
+        count[type]++; /*the filter type itself is part of the scanline*/
+        sum[type] = 0;
+        for(x = 0; x < 256; x++)
+        {
+          float p = count[x] / (float)(linebytes + 1);
+          sum[type] += count[x] == 0 ? 0 : flog2(1 / p) * p;
+        }
+        /*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 if(strategy == LFS_PREDEFINED)
+  {
+    for(y = 0; y < h; y++)
+    {
+      size_t outindex = (1 + linebytes) * y; /*the extra filterbyte added to each row*/
+      size_t inindex = linebytes * y;
+      unsigned char type = settings->predefined_filters[y];
+      out[outindex] = type; /*filter type byte*/
+      filterScanline(&out[outindex + 1], &in[inindex], prevline, linebytes, bytewidth, type);
+      prevline = &in[inindex];
+    }
+  }
+  else if(strategy == LFS_BRUTE_FORCE)
+  {
+    /*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 = 0;
+    unsigned type = 0, bestType = 0;
+    unsigned char* dummy;
+    LodePNGCompressSettings 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;
+    /*a custom encoder likely doesn't read the btype setting and is optimized for complete PNG
+    images only, so disable it*/
+    zlibsettings.custom_zlib = 0;
+    zlibsettings.custom_deflate = 0;
+    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;
+        /*if(testsize > 8) testsize /= 8;*/ /*it already works good enough by testing a part of the row*/
+
+        filterScanline(attempt[type].data, &in[y * linebytes], prevline, linebytes, bytewidth, type);
+        size[type] = 0;
+        dummy = 0;
+        zlib_compress(&dummy, &size[type], attempt[type].data, testsize, &zlibsettings);
+        lodepng_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]);
+  }
+  else return 88; /* unknown filter strategy */
+
+  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);
+  }
+}
+
+/*
+in: non-interlaced image with size w*h
+out: the same pixels, but re-ordered according to PNG's Adam7 interlacing, with
+ no padding bits between scanlines, but between reduced images so that each
+ reduced image starts at a byte.
+bpp: bits per pixel
+there are no padding bits, not between scanlines, not between reduced images
+in has the following size in bits: w * h * bpp.
+out is possibly bigger due to padding bits between reduced images
+NOTE: comments about padding bits are only relevant if bpp < 8
+*/
+static void Adam7_interlace(unsigned char* out, const unsigned char* in, unsigned w, unsigned h, unsigned bpp)
+{
+  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,
+                                    unsigned w, unsigned h,
+                                    const LodePNGInfo* info_png, const LodePNGEncoderSettings* 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_get_bpp(&info_png->color);
+  unsigned error = 0;
+
+  if(info_png->interlace_method == 0)
+  {
+    *outsize = h + (h * ((w * bpp + 7) / 8)); /*image size plus an extra byte per scanline + possible padding bits*/
+    *out = (unsigned char*)lodepng_malloc(*outsize);
+    if(!(*out) && (*outsize)) error = 83; /*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)
+      {
+        unsigned char* padded = (unsigned char*)lodepng_malloc(h * ((w * bpp + 7) / 8));
+        if(!padded) error = 83; /*alloc fail*/
+        if(!error)
+        {
+          addPaddingBits(padded, in, ((w * bpp + 7) / 8) * 8, w * bpp, h);
+          error = filter(*out, padded, w, h, &info_png->color, settings);
+        }
+        lodepng_free(padded);
+      }
+      else
+      {
+        /*we can immediatly filter into the out buffer, no other steps needed*/
+        error = filter(*out, in, w, h, &info_png->color, settings);
+      }
+    }
+  }
+  else /*interlace_method is 1 (Adam7)*/
+  {
+    unsigned passw[7], passh[7];
+    size_t filter_passstart[8], padded_passstart[8], passstart[8];
+    unsigned char* adam7;
+
+    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*)lodepng_malloc(*outsize);
+    if(!(*out)) error = 83; /*alloc fail*/
+
+    adam7 = (unsigned char*)lodepng_malloc(passstart[7]);
+    if(!adam7 && passstart[7]) error = 83; /*alloc fail*/
+
+    if(!error)
+    {
+      unsigned i;
+
+      Adam7_interlace(adam7, in, w, h, bpp);
+      for(i = 0; i < 7; i++)
+      {
+        if(bpp < 8)
+        {
+          unsigned char* padded = (unsigned char*)lodepng_malloc(padded_passstart[i + 1] - padded_passstart[i]);
+          if(!padded) ERROR_BREAK(83); /*alloc fail*/
+          addPaddingBits(padded, &adam7[passstart[i]],
+                         ((passw[i] * bpp + 7) / 8) * 8, passw[i] * bpp, passh[i]);
+          error = filter(&(*out)[filter_passstart[i]], padded,
+                         passw[i], passh[i], &info_png->color, settings);
+          lodepng_free(padded);
+        }
+        else
+        {
+          error = filter(&(*out)[filter_passstart[i]], &adam7[padded_passstart[i]],
+                         passw[i], passh[i], &info_png->color, settings);
+        }
+
+        if(error) break;
+      }
+    }
+
+    lodepng_free(adam7);
+  }
+
+  return error;
+}
+
+/*
+palette must have 4 * palettesize bytes allocated, and given in format RGBARGBARGBARGBA...
+returns 0 if the palette is opaque,
+returns 1 if the palette has a single color with alpha 0 ==> color key
+returns 2 if the palette is semi-translucent.
+*/
+static unsigned getPaletteTranslucency(const unsigned char* palette, size_t palettesize)
+{
+  size_t i;
+  unsigned key = 0;
+  unsigned r = 0, g = 0, b = 0; /*the value of the color with alpha 0, so long as color keying is possible*/
+  for(i = 0; i < palettesize; i++)
+  {
+    if(!key && palette[4 * i + 3] == 0)
+    {
+      r = palette[4 * i + 0]; g = palette[4 * i + 1]; b = palette[4 * i + 2];
+      key = 1;
+      i = (size_t)(-1); /*restart from beginning, to detect earlier opaque colors with key's value*/
+    }
+    else if(palette[4 * i + 3] != 255) return 2;
+    /*when key, no opaque RGB may have key's RGB*/
+    else if(key && r == palette[i * 4 + 0] && g == palette[i * 4 + 1] && b == palette[i * 4 + 2]) return 2;
+  }
+  return key;
+}
+
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+static unsigned addUnknownChunks(ucvector* out, unsigned char* data, size_t datasize)
+{
+  unsigned char* inchunk = data;
+  while((size_t)(inchunk - data) < datasize)
+  {
+    CERROR_TRY_RETURN(lodepng_chunk_append(&out->data, &out->size, inchunk));
+    out->allocsize = out->size; /*fix the allocsize again*/
+    inchunk = lodepng_chunk_next(inchunk);
+  }
+  return 0;
+}
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+
+unsigned lodepng_encode(unsigned char** out, size_t* outsize,
+                        const unsigned char* image, unsigned w, unsigned h,
+                        LodePNGState* state)
+{
+  LodePNGInfo 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;
+  state->error = 0;
+
+  lodepng_info_init(&info);
+  lodepng_info_copy(&info, &state->info_png);
+
+  if((info.color.colortype == LCT_PALETTE || state->encoder.force_palette)
+      && (info.color.palettesize == 0 || info.color.palettesize > 256))
+  {
+    state->error = 68; /*invalid palette size, it is only allowed to be 1-256*/
+    return state->error;
+  }
+
+  if(state->encoder.auto_convert)
+  {
+    state->error = lodepng_auto_choose_color(&info.color, image, w, h, &state->info_raw);
+  }
+  if(state->error) return state->error;
+
+  if(state->encoder.zlibsettings.btype > 2)
+  {
+    CERROR_RETURN_ERROR(state->error, 61); /*error: unexisting btype*/
+  }
+  if(state->info_png.interlace_method > 1)
+  {
+    CERROR_RETURN_ERROR(state->error, 71); /*error: unexisting interlace mode*/
+  }
+
+  state->error = checkColorValidity(info.color.colortype, info.color.bitdepth);
+  if(state->error) return state->error; /*error: unexisting color type given*/
+  state->error = checkColorValidity(state->info_raw.colortype, state->info_raw.bitdepth);
+  if(state->error) return state->error; /*error: unexisting color type given*/
+
+  if(!lodepng_color_mode_equal(&state->info_raw, &info.color))
+  {
+    unsigned char* converted;
+    size_t size = (w * h * lodepng_get_bpp(&info.color) + 7) / 8;
+
+    converted = (unsigned char*)lodepng_malloc(size);
+    if(!converted && size) state->error = 83; /*alloc fail*/
+    if(!state->error)
+    {
+      state->error = lodepng_convert(converted, image, &info.color, &state->info_raw, w, h);
+    }
+    if(!state->error) preProcessScanlines(&data, &datasize, converted, w, h, &info, &state->encoder);
+    lodepng_free(converted);
+  }
+  else preProcessScanlines(&data, &datasize, image, w, h, &info, &state->encoder);
+
+  ucvector_init(&outv);
+  while(!state->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.colortype, info.color.bitdepth, info.interlace_method);
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+    /*unknown chunks between IHDR and PLTE*/
+    if(info.unknown_chunks_data[0])
+    {
+      state->error = addUnknownChunks(&outv, info.unknown_chunks_data[0], info.unknown_chunks_size[0]);
+      if(state->error) break;
+    }
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+    /*PLTE*/
+    if(info.color.colortype == LCT_PALETTE)
+    {
+      addChunk_PLTE(&outv, &info.color);
+    }
+    if(state->encoder.force_palette && (info.color.colortype == LCT_RGB || info.color.colortype == LCT_RGBA))
+    {
+      addChunk_PLTE(&outv, &info.color);
+    }
+    /*tRNS*/
+    if(info.color.colortype == LCT_PALETTE && getPaletteTranslucency(info.color.palette, info.color.palettesize) != 0)
+    {
+      addChunk_tRNS(&outv, &info.color);
+    }
+    if((info.color.colortype == LCT_GREY || info.color.colortype == LCT_RGB) && 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);
+
+    /*unknown chunks between PLTE and IDAT*/
+    if(info.unknown_chunks_data[1])
+    {
+      state->error = addUnknownChunks(&outv, info.unknown_chunks_data[1], info.unknown_chunks_size[1]);
+      if(state->error) break;
+    }
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+    /*IDAT (multiple IDAT chunks must be consecutive)*/
+    state->error = addChunk_IDAT(&outv, data, datasize, &state->encoder.zlibsettings);
+    if(state->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)
+      {
+        state->error = 66; /*text chunk too large*/
+        break;
+      }
+      if(strlen(info.text_keys[i]) < 1)
+      {
+        state->error = 67; /*text chunk too small*/
+        break;
+      }
+      if(state->encoder.text_compression)
+      {
+        addChunk_zTXt(&outv, info.text_keys[i], info.text_strings[i], &state->encoder.zlibsettings);
+      }
+      else
+      {
+        addChunk_tEXt(&outv, info.text_keys[i], info.text_strings[i]);
+      }
+    }
+    /*LodePNG version id in text chunk*/
+    if(state->encoder.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)
+      {
+        state->error = 66; /*text chunk too large*/
+        break;
+      }
+      if(strlen(info.itext_keys[i]) < 1)
+      {
+        state->error = 67; /*text chunk too small*/
+        break;
+      }
+      addChunk_iTXt(&outv, state->encoder.text_compression,
+                    info.itext_keys[i], info.itext_langtags[i], info.itext_transkeys[i], info.itext_strings[i],
+                    &state->encoder.zlibsettings);
+    }
+
+    /*unknown chunks between IDAT and IEND*/
+    if(info.unknown_chunks_data[2])
+    {
+      state->error = addUnknownChunks(&outv, info.unknown_chunks_data[2], info.unknown_chunks_size[2]);
+      if(state->error) break;
+    }
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+    addChunk_IEND(&outv);
+
+    break; /*this isn't really a while loop; no error happened so break out now!*/
+  }
+
+  lodepng_info_cleanup(&info);
+  lodepng_free(data);
+  /*instead of cleaning the vector up, give it to the output*/
+  *out = outv.data;
+  *outsize = outv.size;
+
+  return state->error;
+}
+
+unsigned lodepng_encode_memory(unsigned char** out, size_t* outsize, const unsigned char* image,
+                               unsigned w, unsigned h, LodePNGColorType colortype, unsigned bitdepth)
+{
+  unsigned error;
+  LodePNGState state;
+  lodepng_state_init(&state);
+  state.info_raw.colortype = colortype;
+  state.info_raw.bitdepth = bitdepth;
+  state.info_png.color.colortype = colortype;
+  state.info_png.color.bitdepth = bitdepth;
+  lodepng_encode(out, outsize, image, w, h, &state);
+  error = state.error;
+  lodepng_state_cleanup(&state);
+  return error;
+}
+
+unsigned lodepng_encode32(unsigned char** out, size_t* outsize, const unsigned char* image, unsigned w, unsigned h)
+{
+  return lodepng_encode_memory(out, outsize, image, w, h, LCT_RGBA, 8);
+}
+
+unsigned lodepng_encode24(unsigned char** out, size_t* outsize, const unsigned char* image, unsigned w, unsigned h)
+{
+  return lodepng_encode_memory(out, outsize, image, w, h, LCT_RGB, 8);
+}
+
+#ifdef LODEPNG_COMPILE_DISK
+unsigned lodepng_encode_file(const char* filename, const unsigned char* image, unsigned w, unsigned h,
+                             LodePNGColorType colortype, unsigned bitdepth)
+{
+  unsigned char* buffer;
+  size_t buffersize;
+  unsigned error = lodepng_encode_memory(&buffer, &buffersize, image, w, h, colortype, bitdepth);
+  if(!error) error = lodepng_save_file(buffer, buffersize, filename);
+  lodepng_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, LCT_RGBA, 8);
+}
+
+unsigned lodepng_encode24_file(const char* filename, const unsigned char* image, unsigned w, unsigned h)
+{
+  return lodepng_encode_file(filename, image, w, h, LCT_RGB, 8);
+}
+#endif /*LODEPNG_COMPILE_DISK*/
+
+void lodepng_encoder_settings_init(LodePNGEncoderSettings* settings)
+{
+  lodepng_compress_settings_init(&settings->zlibsettings);
+  settings->filter_palette_zero = 1;
+  settings->filter_strategy = LFS_MINSUM;
+  settings->auto_convert = 1;
+  settings->force_palette = 0;
+  settings->predefined_filters = 0;
+#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
+  settings->add_id = 0;
+  settings->text_compression = 1;
+#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
+}
+
+#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";
+    /*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";
+    case 54: return "repeat symbol in tree while there was no value symbol yet";
+    /*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 "requested color 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 color 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";
+    case 82: return "color conversion to palette requested while a color isn't in palette";
+    case 83: return "memory allocation failed";
+    case 84: return "given image too small to contain all pixels to be encoded";
+    case 86: return "impossible offset in lz77 encoding (internal bug)";
+    case 87: return "must provide custom zlib function pointer if LODEPNG_COMPILE_ZLIB is not defined";
+    case 88: return "invalid filter strategy given for LodePNGEncoderSettings.filter_strategy";
+    case 89: return "text chunk keyword too short or long: must have size 1-79";
+    /*the windowsize in the LodePNGCompressSettings. Requiring POT(==> & instead of %) makes encoding 12% faster.*/
+    case 90: return "windowsize must be a power of two";
+  }
+  return "unknown error code";
+}
+#endif /*LODEPNG_COMPILE_ERROR_TEXT*/
+
+/* ////////////////////////////////////////////////////////////////////////// */
+/* ////////////////////////////////////////////////////////////////////////// */
+/* // C++ Wrapper                                                          // */
+/* ////////////////////////////////////////////////////////////////////////// */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+#ifdef LODEPNG_COMPILE_CPP
+namespace lodepng
+{
+
+#ifdef LODEPNG_COMPILE_DISK
+void load_file(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 save_file(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 LodePNGDecompressSettings& settings)
+{
+  unsigned char* buffer = 0;
+  size_t buffersize = 0;
+  unsigned error = zlib_decompress(&buffer, &buffersize, in, insize, &settings);
+  if(buffer)
+  {
+    out.insert(out.end(), &buffer[0], &buffer[buffersize]);
+    lodepng_free(buffer);
+  }
+  return error;
+}
+
+unsigned decompress(std::vector<unsigned char>& out, const std::vector<unsigned char>& in,
+                    const LodePNGDecompressSettings& 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 LodePNGCompressSettings& settings)
+{
+  unsigned char* buffer = 0;
+  size_t buffersize = 0;
+  unsigned error = zlib_compress(&buffer, &buffersize, in, insize, &settings);
+  if(buffer)
+  {
+    out.insert(out.end(), &buffer[0], &buffer[buffersize]);
+    lodepng_free(buffer);
+  }
+  return error;
+}
+
+unsigned compress(std::vector<unsigned char>& out, const std::vector<unsigned char>& in,
+                  const LodePNGCompressSettings& settings)
+{
+  return compress(out, in.empty() ? 0 : &in[0], in.size(), settings);
+}
+#endif //LODEPNG_COMPILE_ENCODER
+#endif //LODEPNG_COMPILE_ZLIB
+
+
+#ifdef LODEPNG_COMPILE_PNG
+
+State::State()
+{
+  lodepng_state_init(this);
+}
+
+State::State(const State& other)
+{
+  lodepng_state_init(this);
+  lodepng_state_copy(this, &other);
+}
+
+State::~State()
+{
+  lodepng_state_cleanup(this);
+}
+
+State& State::operator=(const State& other)
+{
+  lodepng_state_copy(this, &other);
+  return *this;
+}
+
+#ifdef LODEPNG_COMPILE_DECODER
+
+unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h, const unsigned char* in,
+                size_t insize, LodePNGColorType colortype, unsigned bitdepth)
+{
+  unsigned char* buffer;
+  unsigned error = lodepng_decode_memory(&buffer, &w, &h, in, insize, colortype, bitdepth);
+  if(buffer && !error)
+  {
+    State state;
+    state.info_raw.colortype = colortype;
+    state.info_raw.bitdepth = bitdepth;
+    size_t buffersize = lodepng_get_raw_size(w, h, &state.info_raw);
+    out.insert(out.end(), &buffer[0], &buffer[buffersize]);
+    lodepng_free(buffer);
+  }
+  return error;
+}
+
+unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h,
+                const std::vector<unsigned char>& in, LodePNGColorType colortype, unsigned bitdepth)
+{
+  return decode(out, w, h, in.empty() ? 0 : &in[0], (unsigned)in.size(), colortype, bitdepth);
+}
+
+unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h,
+                State& state,
+                const unsigned char* in, size_t insize)
+{
+  unsigned char* buffer = NULL;
+  unsigned error = lodepng_decode(&buffer, &w, &h, &state, in, insize);
+  if(buffer && !error)
+  {
+    size_t buffersize = lodepng_get_raw_size(w, h, &state.info_raw);
+    out.insert(out.end(), &buffer[0], &buffer[buffersize]);
+  }
+  lodepng_free(buffer);
+  return error;
+}
+
+unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h,
+                State& state,
+                const std::vector<unsigned char>& in)
+{
+  return decode(out, w, h, state, in.empty() ? 0 : &in[0], in.size());
+}
+
+#ifdef LODEPNG_COMPILE_DISK
+unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h, const std::string& filename,
+                LodePNGColorType colortype, unsigned bitdepth)
+{
+  std::vector<unsigned char> buffer;
+  load_file(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,
+                LodePNGColorType colortype, unsigned bitdepth)
+{
+  unsigned char* buffer;
+  size_t buffersize;
+  unsigned error = lodepng_encode_memory(&buffer, &buffersize, in, w, h, colortype, bitdepth);
+  if(buffer)
+  {
+    out.insert(out.end(), &buffer[0], &buffer[buffersize]);
+    lodepng_free(buffer);
+  }
+  return error;
+}
+
+unsigned encode(std::vector<unsigned char>& out,
+                const std::vector<unsigned char>& in, unsigned w, unsigned h,
+                LodePNGColorType colortype, unsigned bitdepth)
+{
+  if(lodepng_get_raw_size_lct(w, h, colortype, bitdepth) > in.size()) return 84;
+  return encode(out, in.empty() ? 0 : &in[0], w, h, colortype, bitdepth);
+}
+
+unsigned encode(std::vector<unsigned char>& out,
+                const unsigned char* in, unsigned w, unsigned h,
+                State& state)
+{
+  unsigned char* buffer;
+  size_t buffersize;
+  unsigned error = lodepng_encode(&buffer, &buffersize, in, w, h, &state);
+  if(buffer)
+  {
+    out.insert(out.end(), &buffer[0], &buffer[buffersize]);
+    lodepng_free(buffer);
+  }
+  return error;
+}
+
+unsigned encode(std::vector<unsigned char>& out,
+                const std::vector<unsigned char>& in, unsigned w, unsigned h,
+                State& state)
+{
+  if(lodepng_get_raw_size(w, h, &state.info_raw) > in.size()) return 84;
+  return encode(out, in.empty() ? 0 : &in[0], w, h, state);
+}
+
+#ifdef LODEPNG_COMPILE_DISK
+unsigned encode(const std::string& filename,
+                const unsigned char* in, unsigned w, unsigned h,
+                LodePNGColorType colortype, unsigned bitdepth)
+{
+  std::vector<unsigned char> buffer;
+  unsigned error = encode(buffer, in, w, h, colortype, bitdepth);
+  if(!error) save_file(buffer, filename);
+  return error;
+}
+
+unsigned encode(const std::string& filename,
+                const std::vector<unsigned char>& in, unsigned w, unsigned h,
+                LodePNGColorType colortype, unsigned bitdepth)
+{
+  if(lodepng_get_raw_size_lct(w, h, colortype, bitdepth) > in.size()) return 84;
+  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 /*LODEPNG_COMPILE_CPP*/