51 with the "LODEPNG_COMPILE_" #defines divide this up further in an intermixed way.
64 /*The malloc, realloc and free functions defined here with "lodepng_" in front
208 -The string tools are made to avoid problems with compilers that declare things like strncat as dep…
210 -As with many other structs in this file, the init and cleanup functions serve as ctor and dtor.
310 /* dynamically allocates a new string with a copy of the null terminated input text */
563 /* Get bits without advancing the bit pointer. Must have enough bits available with ensureBits. Max…
569 /* Must have enough bits available with ensureBits */
575 /* Must have enough bits available with ensureBits */
720   /*initialize with an invalid length to indicate unused entries*/  in HuffmanTree_makeTable()
751 …if(tree->table_len[index] != 16) return 55; /*invalid tree: long symbol shares prefix with short s…  in HuffmanTree_makeTable()
756 …  /*long symbol, shares prefix with other long symbols in first lookup table, needs second lookup*/  in HuffmanTree_makeTable()
765       if(maxlen < l) return 55; /*invalid tree: long symbol shares prefix with short symbol*/  in HuffmanTree_makeTable()
780     filled in. Fill them in with an invalid symbol value so returning them from  in HuffmanTree_makeTable()
888 /*creates a new chain node with the given parameters, from the memory in the lists */
917 /*sort the leaves with stable mergesort*/
970   size_t numpresent = 0; /*number of symbols with non-zero frequency*/  in lodepng_huffman_code_lengths()
971   BPMNode* leaves; /*the symbols, only those with > 0 frequency*/  in lodepng_huffman_code_lengths()
1060 /*get the literal and length code tree of a deflated block with fixed tree, as per the deflate spec…
1078 /*get the distance code tree of a deflated block with fixed tree, as specified in the deflate speci…
1120 /*get the tree of a deflated block with fixed tree, as specified in the deflate specification
1128 /*get the tree of a deflated block with dynamic tree, the tree itself is also Huffman compressed wi…
1261 /*inflate a block with dynamic of fixed Huffman tree. btype must be 1 or 2.*/
1502   unsigned short* chainz; /*those with same amount of zeros*/
1585 is in the form of unsigned integers with codes representing for example literal bytes, or
1805 /*Deflate for a block of type "dynamic", that is, with freely, optimally, created huffman trees*/
1813   literal bytes and length/distance pairs. This is then huffman compressed with  in deflateDynamic()
1822 …/*The lz77 encoded data, represented with integers since there will also be length and distance co…  in deflateDynamic()
1831 …unsigned* bitlen_lld_e = 0; /*bitlen_lld encoded with repeat codes (this is a rudimentary run leng…  in deflateDynamic()
2193 …/*error: only compression method 8: inflate with sliding window of 32k is supported by the PNG spe…  in lodepng_zlib_decompressv()
2274 …unsigned CMF = 120; /*0b01111000: CM 8, CINFO 7. With CINFO 7, any window size up to 32768 can be …  in lodepng_zlib_compress()
2333 …/*compress with dynamic huffman tree (not in the mathematical sense, just not the predefined one)*/  in lodepng_compress_settings_init()
2434 /* The color channel bits of less-than-8-bit pixels are read with the MSB of bytes first,
2608 /* like lodepng_chunk_create but with custom allocsize */
2683   /*the palette must have room for up to 256 colors with 4 bytes each.*/  in lodepng_color_mode_alloc_palette()
2687     /*Initialize all unused colors with black, the value used for invalid palette indices.  in lodepng_color_mode_alloc_palette()
2834 …if(lodepng_mulofl(numpixels, 8, &total)) return 1; /* bit pointer with 8-bit color, or 8 bytes per…  in lodepng_pixel_overflow()
2836   /* Bytes per scanline with the expression "(w / 8u) * bpp) + ((w & 7u) * bpp + 7u) / 8u" */  in lodepng_pixel_overflow()
3097 …/*p = the partial index in the byte, e.g. with 4 palettebits it is 0 for first half or 1 for secon…  in addColorBits()
3151 Index should be >= 0 (it's signed to be compatible with using -1 for "doesn't exist")
3256 /*Get RGBA8 color of pixel with index i (y * width + x) from the raw image with given color type.*/
3327 /*Similar to getPixelColorRGBA8, but with all the for loops inside of the color
3329 to the common case of RGBA with 8 bit per channel. buffer must be RGBA with
3426 /*Similar to getPixelColorsRGBA8, but with 3-channel RGB output.*/
3499 /*Get RGBA16 color of pixel with index i (y * width + x) from the raw image with
3555       /*if the input was also palette with same bitdepth, then the color types are also  in lodepng_convert()
3607 any palette index but doesn't have an alpha channel. Idem with ignoring color key. */
3674 /*function used for debug purposes with C++*/
3810 … if(stats->bits < 8) stats->bits = 8; /*PNG has no colored modes with less than 8-bit per channel*/  in lodepng_compute_color_stats()
3819 …if(stats->bits < 8) stats->bits = 8; /*PNG has no alphachannel modes with less than 8-bit per chan…  in lodepng_compute_color_stats()
3830 …if(stats->bits < 8) stats->bits = 8; /*PNG has no alphachannel modes with less than 8-bit per chan…  in lodepng_compute_color_stats()
3862 …if(stats->bits < 8) stats->bits = 8; /*PNG has no alphachannel modes with less than 8-bit per chan…  in lodepng_compute_color_stats()
3880 (with 2 bytes repeating for 8-bit and 65535 for opaque alpha channel). This function is expensive, …
3899 The stats should be computed with lodepng_compute_color_stats.
3923     if(bits < 8) bits = 8; /*PNG has no alphachannel modes with less than 8-bit per channel*/  in auto_choose_color()
3981   /* return input value associated with smallest of pa, pb, pc (with certain priority if equal) */  in paethPredictor()
3998  reduced image with filter bytes
4000  reduced image when without filter bytes but with padded scanlines
4064     CERROR_RETURN_ERROR(state->error, 29); /*error: it doesn't start with a IHDR chunk!*/  in lodepng_inspect()
4204 …this function unfilters a single image (e.g. without interlacing this is called once, with Adam7 s…  in unfilter()
4232 in: Adam7 interlaced image, with no padding bits between scanlines, but between
4234 out: the same pixels, but re-ordered so that they're now a non-interlaced image with size w*h
4263   } else /*bpp < 8: Adam7 with pixels < 8 bit is a bit trickier: with bit pointers*/ {  in Adam7_deinterlace()
4286 …to be removed (except at last scanline of (Adam7-reduced) image) before working with pure image bu…  in removePaddingBits()
4307 the IDAT chunks (with filter index bytes and possible padding bits)
4312 …This function converts the filtered-padded-interlaced data into pure 2D image buffer with the PNG'…  in postProcessScanlines()
4316   NOTE: the in buffer will be overwritten with intermediate data!  in postProcessScanlines()
4534 …it'd still fail with other error checks below if it's too short. This just gives a different error…  in readChunk_iTXt()
4973     from grayscale input color type, to 8-bit grayscale or grayscale with alpha"*/  in lodepng_decode()
5120 /* only adds the chunk if needed (there is a key or palette with alpha) */
5451   out must be a buffer with as size: h + (w * h * bpp + 7u) / 8u, because there are  in filter()
5452   the scanlines with 1 extra byte per scanline  in filter()
5469       use fixed filtering, with the filter None).  in filter()
5470 …* (The other case) If the image type is Grayscale or RGB (with or without Alpha), and the bit dept…  in filter()
5601     better result with dynamic tree anyway. Using the fixed tree sometimes gives worse, but in rare  in filter()
5661 in: non-interlaced image with size w*h
5662 out: the same pixels, but re-ordered according to PNG's Adam7 interlacing, with
5691   } else /*bpp < 8: Adam7 with pixels < 8 bit is a bit trickier: with bit pointers*/ {  in Adam7_interlace()
5716 …This function converts the pure 2D image with the PNG's colortype, into filtered-padded-interlaced…  in preProcessScanlines()
5802   requires using a non-gray color model if there is an ICC profile with "RGB "  in isGrayICCProfile()
5860       /*the PNG specification does not allow to use palette with a GRAY ICC profile, even  in lodepng_encode()
5866 …/*the PNG specification does not allow to use grayscale color with RGB ICC profile, so disallow gr…  in lodepng_encode()
5905       /*Not allowed to use RGB/RGBA/palette with GRAY ICC profile or vice versa,  in lodepng_encode()
6213 …case 68: return "tried to encode a PLTE chunk with a palette that has less than 1 or more than 256…  in lodepng_error_text()
6214     case 69: return "unknown chunk type with 'critical' flag encountered by the decoder";  in lodepng_error_text()
6240     case 95: return "integer overflow with combined idat chunk size";  in lodepng_error_text()
6247 …case 102: return "not allowed to set grayscale ICC profile with colored pixels by PNG specificatio…  in lodepng_error_text()