From 38be0d13830efd2d98281c645c3a60afe05ffece Mon Sep 17 00:00:00 2001 From: Qt by Nokia Date: Wed, 27 Apr 2011 12:05:43 +0200 Subject: Initial import from the monolithic Qt. This is the beginning of revision history for this module. If you want to look at revision history older than this, please refer to the Qt Git wiki for how to use Git history grafting. At the time of writing, this wiki is located here: http://qt.gitorious.org/qt/pages/GitIntroductionWithQt If you have already performed the grafting and you don't see any history beyond this commit, try running "git log" with the "--follow" argument. Branched from the monolithic repo, Qt master branch, at commit 896db169ea224deb96c59ce8af800d019de63f12 --- src/3rdparty/libpng/pngwutil.c | 2948 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 2948 insertions(+) create mode 100644 src/3rdparty/libpng/pngwutil.c (limited to 'src/3rdparty/libpng/pngwutil.c') diff --git a/src/3rdparty/libpng/pngwutil.c b/src/3rdparty/libpng/pngwutil.c new file mode 100644 index 0000000000..2c35785aa1 --- /dev/null +++ b/src/3rdparty/libpng/pngwutil.c @@ -0,0 +1,2948 @@ + +/* pngwutil.c - utilities to write a PNG file + * + * Last changed in libpng 1.5.0 [January 6, 2011] + * Copyright (c) 1998-2011 Glenn Randers-Pehrson + * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) + * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h + */ + +#include "pngpriv.h" + +#ifdef PNG_WRITE_SUPPORTED + +#ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED +/* Place a 32-bit number into a buffer in PNG byte order. We work + * with unsigned numbers for convenience, although one supported + * ancillary chunk uses signed (two's complement) numbers. + */ +void PNGAPI +png_save_uint_32(png_bytep buf, png_uint_32 i) +{ + buf[0] = (png_byte)((i >> 24) & 0xff); + buf[1] = (png_byte)((i >> 16) & 0xff); + buf[2] = (png_byte)((i >> 8) & 0xff); + buf[3] = (png_byte)(i & 0xff); +} + +#ifdef PNG_SAVE_INT_32_SUPPORTED +/* The png_save_int_32 function assumes integers are stored in two's + * complement format. If this isn't the case, then this routine needs to + * be modified to write data in two's complement format. Note that, + * the following works correctly even if png_int_32 has more than 32 bits + * (compare the more complex code required on read for sign extention.) + */ +void PNGAPI +png_save_int_32(png_bytep buf, png_int_32 i) +{ + buf[0] = (png_byte)((i >> 24) & 0xff); + buf[1] = (png_byte)((i >> 16) & 0xff); + buf[2] = (png_byte)((i >> 8) & 0xff); + buf[3] = (png_byte)(i & 0xff); +} +#endif + +/* Place a 16-bit number into a buffer in PNG byte order. + * The parameter is declared unsigned int, not png_uint_16, + * just to avoid potential problems on pre-ANSI C compilers. + */ +void PNGAPI +png_save_uint_16(png_bytep buf, unsigned int i) +{ + buf[0] = (png_byte)((i >> 8) & 0xff); + buf[1] = (png_byte)(i & 0xff); +} +#endif + +/* Simple function to write the signature. If we have already written + * the magic bytes of the signature, or more likely, the PNG stream is + * being embedded into another stream and doesn't need its own signature, + * we should call png_set_sig_bytes() to tell libpng how many of the + * bytes have already been written. + */ +void PNGAPI +png_write_sig(png_structp png_ptr) +{ + png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10}; + +#ifdef PNG_IO_STATE_SUPPORTED + /* Inform the I/O callback that the signature is being written */ + png_ptr->io_state = PNG_IO_WRITING | PNG_IO_SIGNATURE; +#endif + + /* Write the rest of the 8 byte signature */ + png_write_data(png_ptr, &png_signature[png_ptr->sig_bytes], + (png_size_t)(8 - png_ptr->sig_bytes)); + + if (png_ptr->sig_bytes < 3) + png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE; +} + +/* Write a PNG chunk all at once. The type is an array of ASCII characters + * representing the chunk name. The array must be at least 4 bytes in + * length, and does not need to be null terminated. To be safe, pass the + * pre-defined chunk names here, and if you need a new one, define it + * where the others are defined. The length is the length of the data. + * All the data must be present. If that is not possible, use the + * png_write_chunk_start(), png_write_chunk_data(), and png_write_chunk_end() + * functions instead. + */ +void PNGAPI +png_write_chunk(png_structp png_ptr, png_const_bytep chunk_name, + png_const_bytep data, png_size_t length) +{ + if (png_ptr == NULL) + return; + + png_write_chunk_start(png_ptr, chunk_name, (png_uint_32)length); + png_write_chunk_data(png_ptr, data, (png_size_t)length); + png_write_chunk_end(png_ptr); +} + +/* Write the start of a PNG chunk. The type is the chunk type. + * The total_length is the sum of the lengths of all the data you will be + * passing in png_write_chunk_data(). + */ +void PNGAPI +png_write_chunk_start(png_structp png_ptr, png_const_bytep chunk_name, + png_uint_32 length) +{ + png_byte buf[8]; + + png_debug2(0, "Writing %s chunk, length = %lu", chunk_name, + (unsigned long)length); + + if (png_ptr == NULL) + return; + +#ifdef PNG_IO_STATE_SUPPORTED + /* Inform the I/O callback that the chunk header is being written. + * PNG_IO_CHUNK_HDR requires a single I/O call. + */ + png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_HDR; +#endif + + /* Write the length and the chunk name */ + png_save_uint_32(buf, length); + png_memcpy(buf + 4, chunk_name, 4); + png_write_data(png_ptr, buf, (png_size_t)8); + + /* Put the chunk name into png_ptr->chunk_name */ + png_memcpy(png_ptr->chunk_name, chunk_name, 4); + + /* Reset the crc and run it over the chunk name */ + png_reset_crc(png_ptr); + + png_calculate_crc(png_ptr, chunk_name, 4); + +#ifdef PNG_IO_STATE_SUPPORTED + /* Inform the I/O callback that chunk data will (possibly) be written. + * PNG_IO_CHUNK_DATA does NOT require a specific number of I/O calls. + */ + png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_DATA; +#endif +} + +/* Write the data of a PNG chunk started with png_write_chunk_start(). + * Note that multiple calls to this function are allowed, and that the + * sum of the lengths from these calls *must* add up to the total_length + * given to png_write_chunk_start(). + */ +void PNGAPI +png_write_chunk_data(png_structp png_ptr, png_const_bytep data, + png_size_t length) +{ + /* Write the data, and run the CRC over it */ + if (png_ptr == NULL) + return; + + if (data != NULL && length > 0) + { + png_write_data(png_ptr, data, length); + + /* Update the CRC after writing the data, + * in case that the user I/O routine alters it. + */ + png_calculate_crc(png_ptr, data, length); + } +} + +/* Finish a chunk started with png_write_chunk_start(). */ +void PNGAPI +png_write_chunk_end(png_structp png_ptr) +{ + png_byte buf[4]; + + if (png_ptr == NULL) return; + +#ifdef PNG_IO_STATE_SUPPORTED + /* Inform the I/O callback that the chunk CRC is being written. + * PNG_IO_CHUNK_CRC requires a single I/O function call. + */ + png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_CRC; +#endif + + /* Write the crc in a single operation */ + png_save_uint_32(buf, png_ptr->crc); + + png_write_data(png_ptr, buf, (png_size_t)4); +} + +#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_iCCP_SUPPORTED) +/* This pair of functions encapsulates the operation of (a) compressing a + * text string, and (b) issuing it later as a series of chunk data writes. + * The compression_state structure is shared context for these functions + * set up by the caller in order to make the whole mess thread-safe. + */ + +typedef struct +{ + png_const_bytep input; /* The uncompressed input data */ + png_size_t input_len; /* Its length */ + int num_output_ptr; /* Number of output pointers used */ + int max_output_ptr; /* Size of output_ptr */ + png_bytep *output_ptr; /* Array of pointers to output */ +} compression_state; + +/* Compress given text into storage in the png_ptr structure */ +static int /* PRIVATE */ +png_text_compress(png_structp png_ptr, + png_const_charp text, png_size_t text_len, int compression, + compression_state *comp) +{ + int ret; + + comp->num_output_ptr = 0; + comp->max_output_ptr = 0; + comp->output_ptr = NULL; + comp->input = NULL; + comp->input_len = 0; + + /* We may just want to pass the text right through */ + if (compression == PNG_TEXT_COMPRESSION_NONE) + { + comp->input = (png_const_bytep)text; + comp->input_len = text_len; + return((int)text_len); + } + + if (compression >= PNG_TEXT_COMPRESSION_LAST) + { +#ifdef PNG_CONSOLE_IO_SUPPORTED + char msg[50]; + png_snprintf(msg, 50, "Unknown compression type %d", compression); + png_warning(png_ptr, msg); +#else + png_warning(png_ptr, "Unknown compression type"); +#endif + } + + /* We can't write the chunk until we find out how much data we have, + * which means we need to run the compressor first and save the + * output. This shouldn't be a problem, as the vast majority of + * comments should be reasonable, but we will set up an array of + * malloc'd pointers to be sure. + * + * If we knew the application was well behaved, we could simplify this + * greatly by assuming we can always malloc an output buffer large + * enough to hold the compressed text ((1001 * text_len / 1000) + 12) + * and malloc this directly. The only time this would be a bad idea is + * if we can't malloc more than 64K and we have 64K of random input + * data, or if the input string is incredibly large (although this + * wouldn't cause a failure, just a slowdown due to swapping). + */ + + /* Set up the compression buffers */ + /* TODO: the following cast hides a potential overflow problem. */ + png_ptr->zstream.avail_in = (uInt)text_len; + /* NOTE: assume zlib doesn't overwrite the input */ + png_ptr->zstream.next_in = (Bytef *)text; + png_ptr->zstream.avail_out = png_ptr->zbuf_size; + png_ptr->zstream.next_out = png_ptr->zbuf; + + /* This is the same compression loop as in png_write_row() */ + do + { + /* Compress the data */ + ret = deflate(&png_ptr->zstream, Z_NO_FLUSH); + + if (ret != Z_OK) + { + /* Error */ + if (png_ptr->zstream.msg != NULL) + png_error(png_ptr, png_ptr->zstream.msg); + + else + png_error(png_ptr, "zlib error"); + } + + /* Check to see if we need more room */ + if (!(png_ptr->zstream.avail_out)) + { + /* Make sure the output array has room */ + if (comp->num_output_ptr >= comp->max_output_ptr) + { + int old_max; + + old_max = comp->max_output_ptr; + comp->max_output_ptr = comp->num_output_ptr + 4; + if (comp->output_ptr != NULL) + { + png_bytepp old_ptr; + + old_ptr = comp->output_ptr; + + comp->output_ptr = (png_bytepp)png_malloc(png_ptr, + (png_alloc_size_t) + (comp->max_output_ptr * png_sizeof(png_charpp))); + + png_memcpy(comp->output_ptr, old_ptr, old_max + * png_sizeof(png_charp)); + + png_free(png_ptr, old_ptr); + } + else + comp->output_ptr = (png_bytepp)png_malloc(png_ptr, + (png_alloc_size_t) + (comp->max_output_ptr * png_sizeof(png_charp))); + } + + /* Save the data */ + comp->output_ptr[comp->num_output_ptr] = + (png_bytep)png_malloc(png_ptr, + (png_alloc_size_t)png_ptr->zbuf_size); + + png_memcpy(comp->output_ptr[comp->num_output_ptr], png_ptr->zbuf, + png_ptr->zbuf_size); + + comp->num_output_ptr++; + + /* and reset the buffer */ + png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; + png_ptr->zstream.next_out = png_ptr->zbuf; + } + /* Continue until we don't have any more to compress */ + } while (png_ptr->zstream.avail_in); + + /* Finish the compression */ + do + { + /* Tell zlib we are finished */ + ret = deflate(&png_ptr->zstream, Z_FINISH); + + if (ret == Z_OK) + { + /* Check to see if we need more room */ + if (!(png_ptr->zstream.avail_out)) + { + /* Check to make sure our output array has room */ + if (comp->num_output_ptr >= comp->max_output_ptr) + { + int old_max; + + old_max = comp->max_output_ptr; + comp->max_output_ptr = comp->num_output_ptr + 4; + if (comp->output_ptr != NULL) + { + png_bytepp old_ptr; + + old_ptr = comp->output_ptr; + + /* This could be optimized to realloc() */ + comp->output_ptr = (png_bytepp)png_malloc(png_ptr, + (png_alloc_size_t)(comp->max_output_ptr * + png_sizeof(png_charp))); + + png_memcpy(comp->output_ptr, old_ptr, + old_max * png_sizeof(png_charp)); + + png_free(png_ptr, old_ptr); + } + + else + comp->output_ptr = (png_bytepp)png_malloc(png_ptr, + (png_alloc_size_t)(comp->max_output_ptr * + png_sizeof(png_charp))); + } + + /* Save the data */ + comp->output_ptr[comp->num_output_ptr] = + (png_bytep)png_malloc(png_ptr, + (png_alloc_size_t)png_ptr->zbuf_size); + + png_memcpy(comp->output_ptr[comp->num_output_ptr], png_ptr->zbuf, + png_ptr->zbuf_size); + + comp->num_output_ptr++; + + /* and reset the buffer pointers */ + png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; + png_ptr->zstream.next_out = png_ptr->zbuf; + } + } + else if (ret != Z_STREAM_END) + { + /* We got an error */ + if (png_ptr->zstream.msg != NULL) + png_error(png_ptr, png_ptr->zstream.msg); + + else + png_error(png_ptr, "zlib error"); + } + } while (ret != Z_STREAM_END); + + /* Text length is number of buffers plus last buffer */ + text_len = png_ptr->zbuf_size * comp->num_output_ptr; + + if (png_ptr->zstream.avail_out < png_ptr->zbuf_size) + text_len += png_ptr->zbuf_size - (png_size_t)png_ptr->zstream.avail_out; + + return((int)text_len); +} + +/* Ship the compressed text out via chunk writes */ +static void /* PRIVATE */ +png_write_compressed_data_out(png_structp png_ptr, compression_state *comp) +{ + int i; + + /* Handle the no-compression case */ + if (comp->input) + { + png_write_chunk_data(png_ptr, comp->input, comp->input_len); + + return; + } + + /* Write saved output buffers, if any */ + for (i = 0; i < comp->num_output_ptr; i++) + { + png_write_chunk_data(png_ptr, comp->output_ptr[i], + (png_size_t)png_ptr->zbuf_size); + + png_free(png_ptr, comp->output_ptr[i]); + } + + if (comp->max_output_ptr != 0) + png_free(png_ptr, comp->output_ptr); + + /* Write anything left in zbuf */ + if (png_ptr->zstream.avail_out < (png_uint_32)png_ptr->zbuf_size) + png_write_chunk_data(png_ptr, png_ptr->zbuf, + (png_size_t)(png_ptr->zbuf_size - png_ptr->zstream.avail_out)); + + /* Reset zlib for another zTXt/iTXt or image data */ + deflateReset(&png_ptr->zstream); + png_ptr->zstream.data_type = Z_BINARY; +} +#endif + +/* Write the IHDR chunk, and update the png_struct with the necessary + * information. Note that the rest of this code depends upon this + * information being correct. + */ +void /* PRIVATE */ +png_write_IHDR(png_structp png_ptr, png_uint_32 width, png_uint_32 height, + int bit_depth, int color_type, int compression_type, int filter_type, + int interlace_type) +{ + PNG_IHDR; + int ret; + + png_byte buf[13]; /* Buffer to store the IHDR info */ + + png_debug(1, "in png_write_IHDR"); + + /* Check that we have valid input data from the application info */ + switch (color_type) + { + case PNG_COLOR_TYPE_GRAY: + switch (bit_depth) + { + case 1: + case 2: + case 4: + case 8: +#ifdef PNG_WRITE_16BIT_SUPPORTED + case 16: +#endif + png_ptr->channels = 1; break; + + default: + png_error(png_ptr, + "Invalid bit depth for grayscale image"); + } + break; + + case PNG_COLOR_TYPE_RGB: +#ifdef PNG_WRITE_16BIT_SUPPORTED + if (bit_depth != 8 && bit_depth != 16) +#else + if (bit_depth != 8) +#endif + png_error(png_ptr, "Invalid bit depth for RGB image"); + + png_ptr->channels = 3; + break; + + case PNG_COLOR_TYPE_PALETTE: + switch (bit_depth) + { + case 1: + case 2: + case 4: + case 8: + png_ptr->channels = 1; + break; + + default: + png_error(png_ptr, "Invalid bit depth for paletted image"); + } + break; + + case PNG_COLOR_TYPE_GRAY_ALPHA: + if (bit_depth != 8 && bit_depth != 16) + png_error(png_ptr, "Invalid bit depth for grayscale+alpha image"); + + png_ptr->channels = 2; + break; + + case PNG_COLOR_TYPE_RGB_ALPHA: +#ifdef PNG_WRITE_16BIT_SUPPORTED + if (bit_depth != 8 && bit_depth != 16) +#else + if (bit_depth != 8) +#endif + png_error(png_ptr, "Invalid bit depth for RGBA image"); + + png_ptr->channels = 4; + break; + + default: + png_error(png_ptr, "Invalid image color type specified"); + } + + if (compression_type != PNG_COMPRESSION_TYPE_BASE) + { + png_warning(png_ptr, "Invalid compression type specified"); + compression_type = PNG_COMPRESSION_TYPE_BASE; + } + + /* Write filter_method 64 (intrapixel differencing) only if + * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and + * 2. Libpng did not write a PNG signature (this filter_method is only + * used in PNG datastreams that are embedded in MNG datastreams) and + * 3. The application called png_permit_mng_features with a mask that + * included PNG_FLAG_MNG_FILTER_64 and + * 4. The filter_method is 64 and + * 5. The color_type is RGB or RGBA + */ + if ( +#ifdef PNG_MNG_FEATURES_SUPPORTED + !((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) && + ((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE) == 0) && + (color_type == PNG_COLOR_TYPE_RGB || + color_type == PNG_COLOR_TYPE_RGB_ALPHA) && + (filter_type == PNG_INTRAPIXEL_DIFFERENCING)) && +#endif + filter_type != PNG_FILTER_TYPE_BASE) + { + png_warning(png_ptr, "Invalid filter type specified"); + filter_type = PNG_FILTER_TYPE_BASE; + } + +#ifdef PNG_WRITE_INTERLACING_SUPPORTED + if (interlace_type != PNG_INTERLACE_NONE && + interlace_type != PNG_INTERLACE_ADAM7) + { + png_warning(png_ptr, "Invalid interlace type specified"); + interlace_type = PNG_INTERLACE_ADAM7; + } +#else + interlace_type=PNG_INTERLACE_NONE; +#endif + + /* Save the relevent information */ + png_ptr->bit_depth = (png_byte)bit_depth; + png_ptr->color_type = (png_byte)color_type; + png_ptr->interlaced = (png_byte)interlace_type; +#ifdef PNG_MNG_FEATURES_SUPPORTED + png_ptr->filter_type = (png_byte)filter_type; +#endif + png_ptr->compression_type = (png_byte)compression_type; + png_ptr->width = width; + png_ptr->height = height; + + png_ptr->pixel_depth = (png_byte)(bit_depth * png_ptr->channels); + png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth, width); + /* Set the usr info, so any transformations can modify it */ + png_ptr->usr_width = png_ptr->width; + png_ptr->usr_bit_depth = png_ptr->bit_depth; + png_ptr->usr_channels = png_ptr->channels; + + /* Pack the header information into the buffer */ + png_save_uint_32(buf, width); + png_save_uint_32(buf + 4, height); + buf[8] = (png_byte)bit_depth; + buf[9] = (png_byte)color_type; + buf[10] = (png_byte)compression_type; + buf[11] = (png_byte)filter_type; + buf[12] = (png_byte)interlace_type; + + /* Write the chunk */ + png_write_chunk(png_ptr, png_IHDR, buf, (png_size_t)13); + + /* Initialize zlib with PNG info */ + png_ptr->zstream.zalloc = png_zalloc; + png_ptr->zstream.zfree = png_zfree; + png_ptr->zstream.opaque = (voidpf)png_ptr; + + if (!(png_ptr->do_filter)) + { + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE || + png_ptr->bit_depth < 8) + png_ptr->do_filter = PNG_FILTER_NONE; + + else + png_ptr->do_filter = PNG_ALL_FILTERS; + } + + if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_STRATEGY)) + { + if (png_ptr->do_filter != PNG_FILTER_NONE) + png_ptr->zlib_strategy = Z_FILTERED; + + else + png_ptr->zlib_strategy = Z_DEFAULT_STRATEGY; + } + + if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_LEVEL)) + png_ptr->zlib_level = Z_DEFAULT_COMPRESSION; + + if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL)) + png_ptr->zlib_mem_level = 8; + + if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS)) + png_ptr->zlib_window_bits = 15; + + if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_METHOD)) + png_ptr->zlib_method = 8; + + ret = deflateInit2(&png_ptr->zstream, png_ptr->zlib_level, + png_ptr->zlib_method, png_ptr->zlib_window_bits, + png_ptr->zlib_mem_level, png_ptr->zlib_strategy); + + if (ret != Z_OK) + { + if (ret == Z_VERSION_ERROR) + png_error(png_ptr, + "zlib failed to initialize compressor -- version error"); + + if (ret == Z_STREAM_ERROR) + png_error(png_ptr, + "zlib failed to initialize compressor -- stream error"); + + if (ret == Z_MEM_ERROR) + png_error(png_ptr, + "zlib failed to initialize compressor -- mem error"); + + png_error(png_ptr, "zlib failed to initialize compressor"); + } + + png_ptr->zstream.next_out = png_ptr->zbuf; + png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; + /* libpng is not interested in zstream.data_type, so set it + * to a predefined value, to avoid its evaluation inside zlib + */ + png_ptr->zstream.data_type = Z_BINARY; + + png_ptr->mode = PNG_HAVE_IHDR; +} + +/* Write the palette. We are careful not to trust png_color to be in the + * correct order for PNG, so people can redefine it to any convenient + * structure. + */ +void /* PRIVATE */ +png_write_PLTE(png_structp png_ptr, png_const_colorp palette, + png_uint_32 num_pal) +{ + PNG_PLTE; + png_uint_32 i; + png_const_colorp pal_ptr; + png_byte buf[3]; + + png_debug(1, "in png_write_PLTE"); + + if (( +#ifdef PNG_MNG_FEATURES_SUPPORTED + !(png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE) && +#endif + num_pal == 0) || num_pal > 256) + { + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + { + png_error(png_ptr, "Invalid number of colors in palette"); + } + + else + { + png_warning(png_ptr, "Invalid number of colors in palette"); + return; + } + } + + if (!(png_ptr->color_type&PNG_COLOR_MASK_COLOR)) + { + png_warning(png_ptr, + "Ignoring request to write a PLTE chunk in grayscale PNG"); + + return; + } + + png_ptr->num_palette = (png_uint_16)num_pal; + png_debug1(3, "num_palette = %d", png_ptr->num_palette); + + png_write_chunk_start(png_ptr, png_PLTE, (png_uint_32)(num_pal * 3)); +#ifdef PNG_POINTER_INDEXING_SUPPORTED + + for (i = 0, pal_ptr = palette; i < num_pal; i++, pal_ptr++) + { + buf[0] = pal_ptr->red; + buf[1] = pal_ptr->green; + buf[2] = pal_ptr->blue; + png_write_chunk_data(png_ptr, buf, (png_size_t)3); + } + +#else + /* This is a little slower but some buggy compilers need to do this + * instead + */ + pal_ptr=palette; + + for (i = 0; i < num_pal; i++) + { + buf[0] = pal_ptr[i].red; + buf[1] = pal_ptr[i].green; + buf[2] = pal_ptr[i].blue; + png_write_chunk_data(png_ptr, buf, (png_size_t)3); + } + +#endif + png_write_chunk_end(png_ptr); + png_ptr->mode |= PNG_HAVE_PLTE; +} + +/* Write an IDAT chunk */ +void /* PRIVATE */ +png_write_IDAT(png_structp png_ptr, png_bytep data, png_size_t length) +{ + PNG_IDAT; + + png_debug(1, "in png_write_IDAT"); + + /* Optimize the CMF field in the zlib stream. */ + /* This hack of the zlib stream is compliant to the stream specification. */ + if (!(png_ptr->mode & PNG_HAVE_IDAT) && + png_ptr->compression_type == PNG_COMPRESSION_TYPE_BASE) + { + unsigned int z_cmf = data[0]; /* zlib compression method and flags */ + if ((z_cmf & 0x0f) == 8 && (z_cmf & 0xf0) <= 0x70) + { + /* Avoid memory underflows and multiplication overflows. + * + * The conditions below are practically always satisfied; + * however, they still must be checked. + */ + if (length >= 2 && + png_ptr->height < 16384 && png_ptr->width < 16384) + { + png_uint_32 uncompressed_idat_size = png_ptr->height * + ((png_ptr->width * + png_ptr->channels * png_ptr->bit_depth + 15) >> 3); + unsigned int z_cinfo = z_cmf >> 4; + unsigned int half_z_window_size = 1 << (z_cinfo + 7); + while (uncompressed_idat_size <= half_z_window_size && + half_z_window_size >= 256) + { + z_cinfo--; + half_z_window_size >>= 1; + } + + z_cmf = (z_cmf & 0x0f) | (z_cinfo << 4); + + if (data[0] != z_cmf) + { + int tmp; + data[0] = (png_byte)z_cmf; + tmp = data[1] & 0xe0; + tmp += 0x1f - ((z_cmf << 8) + tmp) % 0x1f; + data[1] = (png_byte)tmp; + } + } + } + + else + png_error(png_ptr, + "Invalid zlib compression method or flags in IDAT"); + } + + png_write_chunk(png_ptr, png_IDAT, data, length); + png_ptr->mode |= PNG_HAVE_IDAT; +} + +/* Write an IEND chunk */ +void /* PRIVATE */ +png_write_IEND(png_structp png_ptr) +{ + PNG_IEND; + + png_debug(1, "in png_write_IEND"); + + png_write_chunk(png_ptr, png_IEND, NULL, (png_size_t)0); + png_ptr->mode |= PNG_HAVE_IEND; +} + +#ifdef PNG_WRITE_gAMA_SUPPORTED +/* Write a gAMA chunk */ +void /* PRIVATE */ +png_write_gAMA_fixed(png_structp png_ptr, png_fixed_point file_gamma) +{ + PNG_gAMA; + png_byte buf[4]; + + png_debug(1, "in png_write_gAMA"); + + /* file_gamma is saved in 1/100,000ths */ + png_save_uint_32(buf, (png_uint_32)file_gamma); + png_write_chunk(png_ptr, png_gAMA, buf, (png_size_t)4); +} +#endif + +#ifdef PNG_WRITE_sRGB_SUPPORTED +/* Write a sRGB chunk */ +void /* PRIVATE */ +png_write_sRGB(png_structp png_ptr, int srgb_intent) +{ + PNG_sRGB; + png_byte buf[1]; + + png_debug(1, "in png_write_sRGB"); + + if (srgb_intent >= PNG_sRGB_INTENT_LAST) + png_warning(png_ptr, + "Invalid sRGB rendering intent specified"); + + buf[0]=(png_byte)srgb_intent; + png_write_chunk(png_ptr, png_sRGB, buf, (png_size_t)1); +} +#endif + +#ifdef PNG_WRITE_iCCP_SUPPORTED +/* Write an iCCP chunk */ +void /* PRIVATE */ +png_write_iCCP(png_structp png_ptr, png_const_charp name, int compression_type, + png_const_charp profile, int profile_len) +{ + PNG_iCCP; + png_size_t name_len; + png_charp new_name; + compression_state comp; + int embedded_profile_len = 0; + + png_debug(1, "in png_write_iCCP"); + + comp.num_output_ptr = 0; + comp.max_output_ptr = 0; + comp.output_ptr = NULL; + comp.input = NULL; + comp.input_len = 0; + + if ((name_len = png_check_keyword(png_ptr, name, &new_name)) == 0) + return; + + if (compression_type != PNG_COMPRESSION_TYPE_BASE) + png_warning(png_ptr, "Unknown compression type in iCCP chunk"); + + if (profile == NULL) + profile_len = 0; + + if (profile_len > 3) + embedded_profile_len = + ((*( (png_const_bytep)profile ))<<24) | + ((*( (png_const_bytep)profile + 1))<<16) | + ((*( (png_const_bytep)profile + 2))<< 8) | + ((*( (png_const_bytep)profile + 3)) ); + + if (embedded_profile_len < 0) + { + png_warning(png_ptr, + "Embedded profile length in iCCP chunk is negative"); + + png_free(png_ptr, new_name); + return; + } + + if (profile_len < embedded_profile_len) + { + png_warning(png_ptr, + "Embedded profile length too large in iCCP chunk"); + + png_free(png_ptr, new_name); + return; + } + + if (profile_len > embedded_profile_len) + { + png_warning(png_ptr, + "Truncating profile to actual length in iCCP chunk"); + + profile_len = embedded_profile_len; + } + + if (profile_len) + profile_len = png_text_compress(png_ptr, profile, + (png_size_t)profile_len, PNG_COMPRESSION_TYPE_BASE, &comp); + + /* Make sure we include the NULL after the name and the compression type */ + png_write_chunk_start(png_ptr, png_iCCP, + (png_uint_32)(name_len + profile_len + 2)); + + new_name[name_len + 1] = 0x00; + + png_write_chunk_data(png_ptr, (png_bytep)new_name, + (png_size_t)(name_len + 2)); + + if (profile_len) + png_write_compressed_data_out(png_ptr, &comp); + + png_write_chunk_end(png_ptr); + png_free(png_ptr, new_name); +} +#endif + +#ifdef PNG_WRITE_sPLT_SUPPORTED +/* Write a sPLT chunk */ +void /* PRIVATE */ +png_write_sPLT(png_structp png_ptr, png_const_sPLT_tp spalette) +{ + PNG_sPLT; + png_size_t name_len; + png_charp new_name; + png_byte entrybuf[10]; + png_size_t entry_size = (spalette->depth == 8 ? 6 : 10); + png_size_t palette_size = entry_size * spalette->nentries; + png_sPLT_entryp ep; +#ifndef PNG_POINTER_INDEXING_SUPPORTED + int i; +#endif + + png_debug(1, "in png_write_sPLT"); + + if ((name_len = png_check_keyword(png_ptr,spalette->name, &new_name))==0) + return; + + /* Make sure we include the NULL after the name */ + png_write_chunk_start(png_ptr, png_sPLT, + (png_uint_32)(name_len + 2 + palette_size)); + + png_write_chunk_data(png_ptr, (png_bytep)new_name, + (png_size_t)(name_len + 1)); + + png_write_chunk_data(png_ptr, &spalette->depth, (png_size_t)1); + + /* Loop through each palette entry, writing appropriately */ +#ifdef PNG_POINTER_INDEXING_SUPPORTED + for (ep = spalette->entries; epentries + spalette->nentries; ep++) + { + if (spalette->depth == 8) + { + entrybuf[0] = (png_byte)ep->red; + entrybuf[1] = (png_byte)ep->green; + entrybuf[2] = (png_byte)ep->blue; + entrybuf[3] = (png_byte)ep->alpha; + png_save_uint_16(entrybuf + 4, ep->frequency); + } + + else + { + png_save_uint_16(entrybuf + 0, ep->red); + png_save_uint_16(entrybuf + 2, ep->green); + png_save_uint_16(entrybuf + 4, ep->blue); + png_save_uint_16(entrybuf + 6, ep->alpha); + png_save_uint_16(entrybuf + 8, ep->frequency); + } + + png_write_chunk_data(png_ptr, entrybuf, (png_size_t)entry_size); + } +#else + ep=spalette->entries; + for (i = 0; i>spalette->nentries; i++) + { + if (spalette->depth == 8) + { + entrybuf[0] = (png_byte)ep[i].red; + entrybuf[1] = (png_byte)ep[i].green; + entrybuf[2] = (png_byte)ep[i].blue; + entrybuf[3] = (png_byte)ep[i].alpha; + png_save_uint_16(entrybuf + 4, ep[i].frequency); + } + + else + { + png_save_uint_16(entrybuf + 0, ep[i].red); + png_save_uint_16(entrybuf + 2, ep[i].green); + png_save_uint_16(entrybuf + 4, ep[i].blue); + png_save_uint_16(entrybuf + 6, ep[i].alpha); + png_save_uint_16(entrybuf + 8, ep[i].frequency); + } + + png_write_chunk_data(png_ptr, entrybuf, (png_size_t)entry_size); + } +#endif + + png_write_chunk_end(png_ptr); + png_free(png_ptr, new_name); +} +#endif + +#ifdef PNG_WRITE_sBIT_SUPPORTED +/* Write the sBIT chunk */ +void /* PRIVATE */ +png_write_sBIT(png_structp png_ptr, png_const_color_8p sbit, int color_type) +{ + PNG_sBIT; + png_byte buf[4]; + png_size_t size; + + png_debug(1, "in png_write_sBIT"); + + /* Make sure we don't depend upon the order of PNG_COLOR_8 */ + if (color_type & PNG_COLOR_MASK_COLOR) + { + png_byte maxbits; + + maxbits = (png_byte)(color_type==PNG_COLOR_TYPE_PALETTE ? 8 : + png_ptr->usr_bit_depth); + + if (sbit->red == 0 || sbit->red > maxbits || + sbit->green == 0 || sbit->green > maxbits || + sbit->blue == 0 || sbit->blue > maxbits) + { + png_warning(png_ptr, "Invalid sBIT depth specified"); + return; + } + + buf[0] = sbit->red; + buf[1] = sbit->green; + buf[2] = sbit->blue; + size = 3; + } + + else + { + if (sbit->gray == 0 || sbit->gray > png_ptr->usr_bit_depth) + { + png_warning(png_ptr, "Invalid sBIT depth specified"); + return; + } + + buf[0] = sbit->gray; + size = 1; + } + + if (color_type & PNG_COLOR_MASK_ALPHA) + { + if (sbit->alpha == 0 || sbit->alpha > png_ptr->usr_bit_depth) + { + png_warning(png_ptr, "Invalid sBIT depth specified"); + return; + } + + buf[size++] = sbit->alpha; + } + + png_write_chunk(png_ptr, png_sBIT, buf, size); +} +#endif + +#ifdef PNG_WRITE_cHRM_SUPPORTED +/* Write the cHRM chunk */ +void /* PRIVATE */ +png_write_cHRM_fixed(png_structp png_ptr, png_fixed_point white_x, + png_fixed_point white_y, png_fixed_point red_x, png_fixed_point red_y, + png_fixed_point green_x, png_fixed_point green_y, png_fixed_point blue_x, + png_fixed_point blue_y) +{ + PNG_cHRM; + png_byte buf[32]; + + png_debug(1, "in png_write_cHRM"); + + /* Each value is saved in 1/100,000ths */ +#ifdef PNG_CHECK_cHRM_SUPPORTED + if (png_check_cHRM_fixed(png_ptr, white_x, white_y, red_x, red_y, + green_x, green_y, blue_x, blue_y)) +#endif + { + png_save_uint_32(buf, (png_uint_32)white_x); + png_save_uint_32(buf + 4, (png_uint_32)white_y); + + png_save_uint_32(buf + 8, (png_uint_32)red_x); + png_save_uint_32(buf + 12, (png_uint_32)red_y); + + png_save_uint_32(buf + 16, (png_uint_32)green_x); + png_save_uint_32(buf + 20, (png_uint_32)green_y); + + png_save_uint_32(buf + 24, (png_uint_32)blue_x); + png_save_uint_32(buf + 28, (png_uint_32)blue_y); + + png_write_chunk(png_ptr, png_cHRM, buf, (png_size_t)32); + } +} +#endif + +#ifdef PNG_WRITE_tRNS_SUPPORTED +/* Write the tRNS chunk */ +void /* PRIVATE */ +png_write_tRNS(png_structp png_ptr, png_const_bytep trans_alpha, + png_const_color_16p tran, int num_trans, int color_type) +{ + PNG_tRNS; + png_byte buf[6]; + + png_debug(1, "in png_write_tRNS"); + + if (color_type == PNG_COLOR_TYPE_PALETTE) + { + if (num_trans <= 0 || num_trans > (int)png_ptr->num_palette) + { + png_warning(png_ptr, "Invalid number of transparent colors specified"); + return; + } + + /* Write the chunk out as it is */ + png_write_chunk(png_ptr, png_tRNS, trans_alpha, (png_size_t)num_trans); + } + + else if (color_type == PNG_COLOR_TYPE_GRAY) + { + /* One 16 bit value */ + if (tran->gray >= (1 << png_ptr->bit_depth)) + { + png_warning(png_ptr, + "Ignoring attempt to write tRNS chunk out-of-range for bit_depth"); + + return; + } + + png_save_uint_16(buf, tran->gray); + png_write_chunk(png_ptr, png_tRNS, buf, (png_size_t)2); + } + + else if (color_type == PNG_COLOR_TYPE_RGB) + { + /* Three 16 bit values */ + png_save_uint_16(buf, tran->red); + png_save_uint_16(buf + 2, tran->green); + png_save_uint_16(buf + 4, tran->blue); +#ifdef PNG_WRITE_16BIT_SUPPORTED + if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4])) +#else + if (buf[0] | buf[2] | buf[4]) +#endif + { + png_warning(png_ptr, + "Ignoring attempt to write 16-bit tRNS chunk when bit_depth is 8"); + return; + } + + png_write_chunk(png_ptr, png_tRNS, buf, (png_size_t)6); + } + + else + { + png_warning(png_ptr, "Can't write tRNS with an alpha channel"); + } +} +#endif + +#ifdef PNG_WRITE_bKGD_SUPPORTED +/* Write the background chunk */ +void /* PRIVATE */ +png_write_bKGD(png_structp png_ptr, png_const_color_16p back, int color_type) +{ + PNG_bKGD; + png_byte buf[6]; + + png_debug(1, "in png_write_bKGD"); + + if (color_type == PNG_COLOR_TYPE_PALETTE) + { + if ( +#ifdef PNG_MNG_FEATURES_SUPPORTED + (png_ptr->num_palette || + (!(png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE))) && +#endif + back->index >= png_ptr->num_palette) + { + png_warning(png_ptr, "Invalid background palette index"); + return; + } + + buf[0] = back->index; + png_write_chunk(png_ptr, png_bKGD, buf, (png_size_t)1); + } + + else if (color_type & PNG_COLOR_MASK_COLOR) + { + png_save_uint_16(buf, back->red); + png_save_uint_16(buf + 2, back->green); + png_save_uint_16(buf + 4, back->blue); +#ifdef PNG_WRITE_16BIT_SUPPORTED + if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4])) +#else + if (buf[0] | buf[2] | buf[4]) +#endif + { + png_warning(png_ptr, + "Ignoring attempt to write 16-bit bKGD chunk when bit_depth is 8"); + + return; + } + + png_write_chunk(png_ptr, png_bKGD, buf, (png_size_t)6); + } + + else + { + if (back->gray >= (1 << png_ptr->bit_depth)) + { + png_warning(png_ptr, + "Ignoring attempt to write bKGD chunk out-of-range for bit_depth"); + + return; + } + + png_save_uint_16(buf, back->gray); + png_write_chunk(png_ptr, png_bKGD, buf, (png_size_t)2); + } +} +#endif + +#ifdef PNG_WRITE_hIST_SUPPORTED +/* Write the histogram */ +void /* PRIVATE */ +png_write_hIST(png_structp png_ptr, png_const_uint_16p hist, int num_hist) +{ + PNG_hIST; + int i; + png_byte buf[3]; + + png_debug(1, "in png_write_hIST"); + + if (num_hist > (int)png_ptr->num_palette) + { + png_debug2(3, "num_hist = %d, num_palette = %d", num_hist, + png_ptr->num_palette); + + png_warning(png_ptr, "Invalid number of histogram entries specified"); + return; + } + + png_write_chunk_start(png_ptr, png_hIST, (png_uint_32)(num_hist * 2)); + + for (i = 0; i < num_hist; i++) + { + png_save_uint_16(buf, hist[i]); + png_write_chunk_data(png_ptr, buf, (png_size_t)2); + } + + png_write_chunk_end(png_ptr); +} +#endif + +#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED) || \ + defined(PNG_WRITE_iCCP_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED) +/* Check that the tEXt or zTXt keyword is valid per PNG 1.0 specification, + * and if invalid, correct the keyword rather than discarding the entire + * chunk. The PNG 1.0 specification requires keywords 1-79 characters in + * length, forbids leading or trailing whitespace, multiple internal spaces, + * and the non-break space (0x80) from ISO 8859-1. Returns keyword length. + * + * The new_key is allocated to hold the corrected keyword and must be freed + * by the calling routine. This avoids problems with trying to write to + * static keywords without having to have duplicate copies of the strings. + */ +png_size_t /* PRIVATE */ +png_check_keyword(png_structp png_ptr, png_const_charp key, png_charpp new_key) +{ + png_size_t key_len; + png_const_charp ikp; + png_charp kp, dp; + int kflag; + int kwarn=0; + + png_debug(1, "in png_check_keyword"); + + *new_key = NULL; + + if (key == NULL || (key_len = png_strlen(key)) == 0) + { + png_warning(png_ptr, "zero length keyword"); + return ((png_size_t)0); + } + + png_debug1(2, "Keyword to be checked is '%s'", key); + + *new_key = (png_charp)png_malloc_warn(png_ptr, (png_uint_32)(key_len + 2)); + + if (*new_key == NULL) + { + png_warning(png_ptr, "Out of memory while procesing keyword"); + return ((png_size_t)0); + } + + /* Replace non-printing characters with a blank and print a warning */ + for (ikp = key, dp = *new_key; *ikp != '\0'; ikp++, dp++) + { + if ((png_byte)*ikp < 0x20 || + ((png_byte)*ikp > 0x7E && (png_byte)*ikp < 0xA1)) + { +#ifdef PNG_CONSOLE_IO_SUPPORTED + char msg[40]; + + png_snprintf(msg, 40, + "invalid keyword character 0x%02X", (png_byte)*ikp); + png_warning(png_ptr, msg); +#else + png_warning(png_ptr, "invalid character in keyword"); +#endif + *dp = ' '; + } + + else + { + *dp = *ikp; + } + } + *dp = '\0'; + + /* Remove any trailing white space. */ + kp = *new_key + key_len - 1; + if (*kp == ' ') + { + png_warning(png_ptr, "trailing spaces removed from keyword"); + + while (*kp == ' ') + { + *(kp--) = '\0'; + key_len--; + } + } + + /* Remove any leading white space. */ + kp = *new_key; + if (*kp == ' ') + { + png_warning(png_ptr, "leading spaces removed from keyword"); + + while (*kp == ' ') + { + kp++; + key_len--; + } + } + + png_debug1(2, "Checking for multiple internal spaces in '%s'", kp); + + /* Remove multiple internal spaces. */ + for (kflag = 0, dp = *new_key; *kp != '\0'; kp++) + { + if (*kp == ' ' && kflag == 0) + { + *(dp++) = *kp; + kflag = 1; + } + + else if (*kp == ' ') + { + key_len--; + kwarn = 1; + } + + else + { + *(dp++) = *kp; + kflag = 0; + } + } + *dp = '\0'; + if (kwarn) + png_warning(png_ptr, "extra interior spaces removed from keyword"); + + if (key_len == 0) + { + png_free(png_ptr, *new_key); + png_warning(png_ptr, "Zero length keyword"); + } + + if (key_len > 79) + { + png_warning(png_ptr, "keyword length must be 1 - 79 characters"); + (*new_key)[79] = '\0'; + key_len = 79; + } + + return (key_len); +} +#endif + +#ifdef PNG_WRITE_tEXt_SUPPORTED +/* Write a tEXt chunk */ +void /* PRIVATE */ +png_write_tEXt(png_structp png_ptr, png_const_charp key, png_const_charp text, + png_size_t text_len) +{ + PNG_tEXt; + png_size_t key_len; + png_charp new_key; + + png_debug(1, "in png_write_tEXt"); + + if ((key_len = png_check_keyword(png_ptr, key, &new_key))==0) + return; + + if (text == NULL || *text == '\0') + text_len = 0; + + else + text_len = png_strlen(text); + + /* Make sure we include the 0 after the key */ + png_write_chunk_start(png_ptr, png_tEXt, + (png_uint_32)(key_len + text_len + 1)); + /* + * We leave it to the application to meet PNG-1.0 requirements on the + * contents of the text. PNG-1.0 through PNG-1.2 discourage the use of + * any non-Latin-1 characters except for NEWLINE. ISO PNG will forbid them. + * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG. + */ + png_write_chunk_data(png_ptr, (png_bytep)new_key, + (png_size_t)(key_len + 1)); + + if (text_len) + png_write_chunk_data(png_ptr, (png_const_bytep)text, + (png_size_t)text_len); + + png_write_chunk_end(png_ptr); + png_free(png_ptr, new_key); +} +#endif + +#ifdef PNG_WRITE_zTXt_SUPPORTED +/* Write a compressed text chunk */ +void /* PRIVATE */ +png_write_zTXt(png_structp png_ptr, png_const_charp key, png_const_charp text, + png_size_t text_len, int compression) +{ + PNG_zTXt; + png_size_t key_len; + png_byte buf; + png_charp new_key; + compression_state comp; + + png_debug(1, "in png_write_zTXt"); + + comp.num_output_ptr = 0; + comp.max_output_ptr = 0; + comp.output_ptr = NULL; + comp.input = NULL; + comp.input_len = 0; + + if ((key_len = png_check_keyword(png_ptr, key, &new_key)) == 0) + { + png_free(png_ptr, new_key); + return; + } + + if (text == NULL || *text == '\0' || compression==PNG_TEXT_COMPRESSION_NONE) + { + png_write_tEXt(png_ptr, new_key, text, (png_size_t)0); + png_free(png_ptr, new_key); + return; + } + + text_len = png_strlen(text); + + /* Compute the compressed data; do it now for the length */ + text_len = png_text_compress(png_ptr, text, text_len, compression, + &comp); + + /* Write start of chunk */ + png_write_chunk_start(png_ptr, png_zTXt, + (png_uint_32)(key_len+text_len + 2)); + + /* Write key */ + png_write_chunk_data(png_ptr, (png_bytep)new_key, + (png_size_t)(key_len + 1)); + + png_free(png_ptr, new_key); + + buf = (png_byte)compression; + + /* Write compression */ + png_write_chunk_data(png_ptr, &buf, (png_size_t)1); + + /* Write the compressed data */ + png_write_compressed_data_out(png_ptr, &comp); + + /* Close the chunk */ + png_write_chunk_end(png_ptr); +} +#endif + +#ifdef PNG_WRITE_iTXt_SUPPORTED +/* Write an iTXt chunk */ +void /* PRIVATE */ +png_write_iTXt(png_structp png_ptr, int compression, png_const_charp key, + png_const_charp lang, png_const_charp lang_key, png_const_charp text) +{ + PNG_iTXt; + png_size_t lang_len, key_len, lang_key_len, text_len; + png_charp new_lang; + png_charp new_key = NULL; + png_byte cbuf[2]; + compression_state comp; + + png_debug(1, "in png_write_iTXt"); + + comp.num_output_ptr = 0; + comp.max_output_ptr = 0; + comp.output_ptr = NULL; + comp.input = NULL; + + if ((key_len = png_check_keyword(png_ptr, key, &new_key)) == 0) + return; + + if ((lang_len = png_check_keyword(png_ptr, lang, &new_lang)) == 0) + { + png_warning(png_ptr, "Empty language field in iTXt chunk"); + new_lang = NULL; + lang_len = 0; + } + + if (lang_key == NULL) + lang_key_len = 0; + + else + lang_key_len = png_strlen(lang_key); + + if (text == NULL) + text_len = 0; + + else + text_len = png_strlen(text); + + /* Compute the compressed data; do it now for the length */ + text_len = png_text_compress(png_ptr, text, text_len, compression - 2, + &comp); + + + /* Make sure we include the compression flag, the compression byte, + * and the NULs after the key, lang, and lang_key parts + */ + + png_write_chunk_start(png_ptr, png_iTXt, (png_uint_32)( + 5 /* comp byte, comp flag, terminators for key, lang and lang_key */ + + key_len + + lang_len + + lang_key_len + + text_len)); + + /* We leave it to the application to meet PNG-1.0 requirements on the + * contents of the text. PNG-1.0 through PNG-1.2 discourage the use of + * any non-Latin-1 characters except for NEWLINE. ISO PNG will forbid them. + * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG. + */ + png_write_chunk_data(png_ptr, (png_bytep)new_key, (png_size_t)(key_len + 1)); + + /* Set the compression flag */ + if (compression == PNG_ITXT_COMPRESSION_NONE || + compression == PNG_TEXT_COMPRESSION_NONE) + cbuf[0] = 0; + + else /* compression == PNG_ITXT_COMPRESSION_zTXt */ + cbuf[0] = 1; + + /* Set the compression method */ + cbuf[1] = 0; + + png_write_chunk_data(png_ptr, cbuf, (png_size_t)2); + + cbuf[0] = 0; + png_write_chunk_data(png_ptr, (new_lang ? (png_const_bytep)new_lang : cbuf), + (png_size_t)(lang_len + 1)); + + png_write_chunk_data(png_ptr, (lang_key ? (png_const_bytep)lang_key : cbuf), + (png_size_t)(lang_key_len + 1)); + + png_write_compressed_data_out(png_ptr, &comp); + + png_write_chunk_end(png_ptr); + + png_free(png_ptr, new_key); + png_free(png_ptr, new_lang); +} +#endif + +#ifdef PNG_WRITE_oFFs_SUPPORTED +/* Write the oFFs chunk */ +void /* PRIVATE */ +png_write_oFFs(png_structp png_ptr, png_int_32 x_offset, png_int_32 y_offset, + int unit_type) +{ + PNG_oFFs; + png_byte buf[9]; + + png_debug(1, "in png_write_oFFs"); + + if (unit_type >= PNG_OFFSET_LAST) + png_warning(png_ptr, "Unrecognized unit type for oFFs chunk"); + + png_save_int_32(buf, x_offset); + png_save_int_32(buf + 4, y_offset); + buf[8] = (png_byte)unit_type; + + png_write_chunk(png_ptr, png_oFFs, buf, (png_size_t)9); +} +#endif +#ifdef PNG_WRITE_pCAL_SUPPORTED +/* Write the pCAL chunk (described in the PNG extensions document) */ +void /* PRIVATE */ +png_write_pCAL(png_structp png_ptr, png_charp purpose, png_int_32 X0, + png_int_32 X1, int type, int nparams, png_const_charp units, + png_charpp params) +{ + PNG_pCAL; + png_size_t purpose_len, units_len, total_len; + png_uint_32p params_len; + png_byte buf[10]; + png_charp new_purpose; + int i; + + png_debug1(1, "in png_write_pCAL (%d parameters)", nparams); + + if (type >= PNG_EQUATION_LAST) + png_warning(png_ptr, "Unrecognized equation type for pCAL chunk"); + + purpose_len = png_check_keyword(png_ptr, purpose, &new_purpose) + 1; + png_debug1(3, "pCAL purpose length = %d", (int)purpose_len); + units_len = png_strlen(units) + (nparams == 0 ? 0 : 1); + png_debug1(3, "pCAL units length = %d", (int)units_len); + total_len = purpose_len + units_len + 10; + + params_len = (png_uint_32p)png_malloc(png_ptr, + (png_alloc_size_t)(nparams * png_sizeof(png_uint_32))); + + /* Find the length of each parameter, making sure we don't count the + * null terminator for the last parameter. + */ + for (i = 0; i < nparams; i++) + { + params_len[i] = png_strlen(params[i]) + (i == nparams - 1 ? 0 : 1); + png_debug2(3, "pCAL parameter %d length = %lu", i, + (unsigned long)params_len[i]); + total_len += (png_size_t)params_len[i]; + } + + png_debug1(3, "pCAL total length = %d", (int)total_len); + png_write_chunk_start(png_ptr, png_pCAL, (png_uint_32)total_len); + png_write_chunk_data(png_ptr, (png_const_bytep)new_purpose, + (png_size_t)purpose_len); + png_save_int_32(buf, X0); + png_save_int_32(buf + 4, X1); + buf[8] = (png_byte)type; + buf[9] = (png_byte)nparams; + png_write_chunk_data(png_ptr, buf, (png_size_t)10); + png_write_chunk_data(png_ptr, (png_const_bytep)units, (png_size_t)units_len); + + png_free(png_ptr, new_purpose); + + for (i = 0; i < nparams; i++) + { + png_write_chunk_data(png_ptr, (png_const_bytep)params[i], + (png_size_t)params_len[i]); + } + + png_free(png_ptr, params_len); + png_write_chunk_end(png_ptr); +} +#endif + +#ifdef PNG_WRITE_sCAL_SUPPORTED +/* Write the sCAL chunk */ +void /* PRIVATE */ +png_write_sCAL_s(png_structp png_ptr, int unit, png_const_charp width, + png_const_charp height) +{ + PNG_sCAL; + png_byte buf[64]; + png_size_t wlen, hlen, total_len; + + png_debug(1, "in png_write_sCAL_s"); + + wlen = png_strlen(width); + hlen = png_strlen(height); + total_len = wlen + hlen + 2; + + if (total_len > 64) + { + png_warning(png_ptr, "Can't write sCAL (buffer too small)"); + return; + } + + buf[0] = (png_byte)unit; + png_memcpy(buf + 1, width, wlen + 1); /* Append the '\0' here */ + png_memcpy(buf + wlen + 2, height, hlen); /* Do NOT append the '\0' here */ + + png_debug1(3, "sCAL total length = %u", (unsigned int)total_len); + png_write_chunk(png_ptr, png_sCAL, buf, total_len); +} +#endif + +#ifdef PNG_WRITE_pHYs_SUPPORTED +/* Write the pHYs chunk */ +void /* PRIVATE */ +png_write_pHYs(png_structp png_ptr, png_uint_32 x_pixels_per_unit, + png_uint_32 y_pixels_per_unit, + int unit_type) +{ + PNG_pHYs; + png_byte buf[9]; + + png_debug(1, "in png_write_pHYs"); + + if (unit_type >= PNG_RESOLUTION_LAST) + png_warning(png_ptr, "Unrecognized unit type for pHYs chunk"); + + png_save_uint_32(buf, x_pixels_per_unit); + png_save_uint_32(buf + 4, y_pixels_per_unit); + buf[8] = (png_byte)unit_type; + + png_write_chunk(png_ptr, png_pHYs, buf, (png_size_t)9); +} +#endif + +#ifdef PNG_WRITE_tIME_SUPPORTED +/* Write the tIME chunk. Use either png_convert_from_struct_tm() + * or png_convert_from_time_t(), or fill in the structure yourself. + */ +void /* PRIVATE */ +png_write_tIME(png_structp png_ptr, png_const_timep mod_time) +{ + PNG_tIME; + png_byte buf[7]; + + png_debug(1, "in png_write_tIME"); + + if (mod_time->month > 12 || mod_time->month < 1 || + mod_time->day > 31 || mod_time->day < 1 || + mod_time->hour > 23 || mod_time->second > 60) + { + png_warning(png_ptr, "Invalid time specified for tIME chunk"); + return; + } + + png_save_uint_16(buf, mod_time->year); + buf[2] = mod_time->month; + buf[3] = mod_time->day; + buf[4] = mod_time->hour; + buf[5] = mod_time->minute; + buf[6] = mod_time->second; + + png_write_chunk(png_ptr, png_tIME, buf, (png_size_t)7); +} +#endif + +/* Initializes the row writing capability of libpng */ +void /* PRIVATE */ +png_write_start_row(png_structp png_ptr) +{ +#ifdef PNG_WRITE_INTERLACING_SUPPORTED + /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ + + /* Start of interlace block */ + int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; + + /* Offset to next interlace block */ + int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; + + /* Start of interlace block in the y direction */ + int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1}; + + /* Offset to next interlace block in the y direction */ + int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; +#endif + + png_size_t buf_size; + + png_debug(1, "in png_write_start_row"); + + buf_size = (png_size_t)(PNG_ROWBYTES( + png_ptr->usr_channels*png_ptr->usr_bit_depth, png_ptr->width) + 1); + + /* Set up row buffer */ + png_ptr->row_buf = (png_bytep)png_malloc(png_ptr, + (png_alloc_size_t)buf_size); + + png_ptr->row_buf[0] = PNG_FILTER_VALUE_NONE; + +#ifdef PNG_WRITE_FILTER_SUPPORTED + /* Set up filtering buffer, if using this filter */ + if (png_ptr->do_filter & PNG_FILTER_SUB) + { + png_ptr->sub_row = (png_bytep)png_malloc(png_ptr, png_ptr->rowbytes + 1); + + png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB; + } + + /* We only need to keep the previous row if we are using one of these. */ + if (png_ptr->do_filter & (PNG_FILTER_AVG | PNG_FILTER_UP | PNG_FILTER_PAETH)) + { + /* Set up previous row buffer */ + png_ptr->prev_row = (png_bytep)png_calloc(png_ptr, + (png_alloc_size_t)buf_size); + + if (png_ptr->do_filter & PNG_FILTER_UP) + { + png_ptr->up_row = (png_bytep)png_malloc(png_ptr, + png_ptr->rowbytes + 1); + + png_ptr->up_row[0] = PNG_FILTER_VALUE_UP; + } + + if (png_ptr->do_filter & PNG_FILTER_AVG) + { + png_ptr->avg_row = (png_bytep)png_malloc(png_ptr, + png_ptr->rowbytes + 1); + + png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG; + } + + if (png_ptr->do_filter & PNG_FILTER_PAETH) + { + png_ptr->paeth_row = (png_bytep)png_malloc(png_ptr, + png_ptr->rowbytes + 1); + + png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH; + } + } +#endif /* PNG_WRITE_FILTER_SUPPORTED */ + +#ifdef PNG_WRITE_INTERLACING_SUPPORTED + /* If interlaced, we need to set up width and height of pass */ + if (png_ptr->interlaced) + { + if (!(png_ptr->transformations & PNG_INTERLACE)) + { + png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 - + png_pass_ystart[0]) / png_pass_yinc[0]; + + png_ptr->usr_width = (png_ptr->width + png_pass_inc[0] - 1 - + png_pass_start[0]) / png_pass_inc[0]; + } + + else + { + png_ptr->num_rows = png_ptr->height; + png_ptr->usr_width = png_ptr->width; + } + } + + else +#endif + { + png_ptr->num_rows = png_ptr->height; + png_ptr->usr_width = png_ptr->width; + } + + png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; + png_ptr->zstream.next_out = png_ptr->zbuf; +} + +/* Internal use only. Called when finished processing a row of data. */ +void /* PRIVATE */ +png_write_finish_row(png_structp png_ptr) +{ +#ifdef PNG_WRITE_INTERLACING_SUPPORTED + /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ + + /* Start of interlace block */ + int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; + + /* Offset to next interlace block */ + int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; + + /* Start of interlace block in the y direction */ + int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1}; + + /* Offset to next interlace block in the y direction */ + int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; +#endif + + int ret; + + png_debug(1, "in png_write_finish_row"); + + /* Next row */ + png_ptr->row_number++; + + /* See if we are done */ + if (png_ptr->row_number < png_ptr->num_rows) + return; + +#ifdef PNG_WRITE_INTERLACING_SUPPORTED + /* If interlaced, go to next pass */ + if (png_ptr->interlaced) + { + png_ptr->row_number = 0; + if (png_ptr->transformations & PNG_INTERLACE) + { + png_ptr->pass++; + } + + else + { + /* Loop until we find a non-zero width or height pass */ + do + { + png_ptr->pass++; + + if (png_ptr->pass >= 7) + break; + + png_ptr->usr_width = (png_ptr->width + + png_pass_inc[png_ptr->pass] - 1 - + png_pass_start[png_ptr->pass]) / + png_pass_inc[png_ptr->pass]; + + png_ptr->num_rows = (png_ptr->height + + png_pass_yinc[png_ptr->pass] - 1 - + png_pass_ystart[png_ptr->pass]) / + png_pass_yinc[png_ptr->pass]; + + if (png_ptr->transformations & PNG_INTERLACE) + break; + + } while (png_ptr->usr_width == 0 || png_ptr->num_rows == 0); + + } + + /* Reset the row above the image for the next pass */ + if (png_ptr->pass < 7) + { + if (png_ptr->prev_row != NULL) + png_memset(png_ptr->prev_row, 0, + (png_size_t)(PNG_ROWBYTES(png_ptr->usr_channels* + png_ptr->usr_bit_depth, png_ptr->width)) + 1); + + return; + } + } +#endif + + /* If we get here, we've just written the last row, so we need + to flush the compressor */ + do + { + /* Tell the compressor we are done */ + ret = deflate(&png_ptr->zstream, Z_FINISH); + + /* Check for an error */ + if (ret == Z_OK) + { + /* Check to see if we need more room */ + if (!(png_ptr->zstream.avail_out)) + { + png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size); + png_ptr->zstream.next_out = png_ptr->zbuf; + png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; + } + } + + else if (ret != Z_STREAM_END) + { + if (png_ptr->zstream.msg != NULL) + png_error(png_ptr, png_ptr->zstream.msg); + + else + png_error(png_ptr, "zlib error"); + } + } while (ret != Z_STREAM_END); + + /* Write any extra space */ + if (png_ptr->zstream.avail_out < png_ptr->zbuf_size) + { + png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size - + png_ptr->zstream.avail_out); + } + + deflateReset(&png_ptr->zstream); + png_ptr->zstream.data_type = Z_BINARY; +} + +#ifdef PNG_WRITE_INTERLACING_SUPPORTED +/* Pick out the correct pixels for the interlace pass. + * The basic idea here is to go through the row with a source + * pointer and a destination pointer (sp and dp), and copy the + * correct pixels for the pass. As the row gets compacted, + * sp will always be >= dp, so we should never overwrite anything. + * See the default: case for the easiest code to understand. + */ +void /* PRIVATE */ +png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass) +{ + /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ + + /* Start of interlace block */ + int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; + + /* Offset to next interlace block */ + int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; + + png_debug(1, "in png_do_write_interlace"); + + /* We don't have to do anything on the last pass (6) */ + if (pass < 6) + { + /* Each pixel depth is handled separately */ + switch (row_info->pixel_depth) + { + case 1: + { + png_bytep sp; + png_bytep dp; + int shift; + int d; + int value; + png_uint_32 i; + png_uint_32 row_width = row_info->width; + + dp = row; + d = 0; + shift = 7; + + for (i = png_pass_start[pass]; i < row_width; + i += png_pass_inc[pass]) + { + sp = row + (png_size_t)(i >> 3); + value = (int)(*sp >> (7 - (int)(i & 0x07))) & 0x01; + d |= (value << shift); + + if (shift == 0) + { + shift = 7; + *dp++ = (png_byte)d; + d = 0; + } + + else + shift--; + + } + if (shift != 7) + *dp = (png_byte)d; + + break; + } + + case 2: + { + png_bytep sp; + png_bytep dp; + int shift; + int d; + int value; + png_uint_32 i; + png_uint_32 row_width = row_info->width; + + dp = row; + shift = 6; + d = 0; + + for (i = png_pass_start[pass]; i < row_width; + i += png_pass_inc[pass]) + { + sp = row + (png_size_t)(i >> 2); + value = (*sp >> ((3 - (int)(i & 0x03)) << 1)) & 0x03; + d |= (value << shift); + + if (shift == 0) + { + shift = 6; + *dp++ = (png_byte)d; + d = 0; + } + + else + shift -= 2; + } + if (shift != 6) + *dp = (png_byte)d; + + break; + } + + case 4: + { + png_bytep sp; + png_bytep dp; + int shift; + int d; + int value; + png_uint_32 i; + png_uint_32 row_width = row_info->width; + + dp = row; + shift = 4; + d = 0; + for (i = png_pass_start[pass]; i < row_width; + i += png_pass_inc[pass]) + { + sp = row + (png_size_t)(i >> 1); + value = (*sp >> ((1 - (int)(i & 0x01)) << 2)) & 0x0f; + d |= (value << shift); + + if (shift == 0) + { + shift = 4; + *dp++ = (png_byte)d; + d = 0; + } + + else + shift -= 4; + } + if (shift != 4) + *dp = (png_byte)d; + + break; + } + + default: + { + png_bytep sp; + png_bytep dp; + png_uint_32 i; + png_uint_32 row_width = row_info->width; + png_size_t pixel_bytes; + + /* Start at the beginning */ + dp = row; + + /* Find out how many bytes each pixel takes up */ + pixel_bytes = (row_info->pixel_depth >> 3); + + /* Loop through the row, only looking at the pixels that matter */ + for (i = png_pass_start[pass]; i < row_width; + i += png_pass_inc[pass]) + { + /* Find out where the original pixel is */ + sp = row + (png_size_t)i * pixel_bytes; + + /* Move the pixel */ + if (dp != sp) + png_memcpy(dp, sp, pixel_bytes); + + /* Next pixel */ + dp += pixel_bytes; + } + break; + } + } + /* Set new row width */ + row_info->width = (row_info->width + + png_pass_inc[pass] - 1 - + png_pass_start[pass]) / + png_pass_inc[pass]; + + row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, + row_info->width); + } +} +#endif + +/* This filters the row, chooses which filter to use, if it has not already + * been specified by the application, and then writes the row out with the + * chosen filter. + */ +#define PNG_MAXSUM (((png_uint_32)(-1)) >> 1) +#define PNG_HISHIFT 10 +#define PNG_LOMASK ((png_uint_32)0xffffL) +#define PNG_HIMASK ((png_uint_32)(~PNG_LOMASK >> PNG_HISHIFT)) +void /* PRIVATE */ +png_write_find_filter(png_structp png_ptr, png_row_infop row_info) +{ + png_bytep best_row; +#ifdef PNG_WRITE_FILTER_SUPPORTED + png_bytep prev_row, row_buf; + png_uint_32 mins, bpp; + png_byte filter_to_do = png_ptr->do_filter; + png_size_t row_bytes = row_info->rowbytes; +#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED + int num_p_filters = (int)png_ptr->num_prev_filters; +#endif + + png_debug(1, "in png_write_find_filter"); + +#ifndef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED + if (png_ptr->row_number == 0 && filter_to_do == PNG_ALL_FILTERS) + { + /* These will never be selected so we need not test them. */ + filter_to_do &= ~(PNG_FILTER_UP | PNG_FILTER_PAETH); + } +#endif + + /* Find out how many bytes offset each pixel is */ + bpp = (row_info->pixel_depth + 7) >> 3; + + prev_row = png_ptr->prev_row; +#endif + best_row = png_ptr->row_buf; +#ifdef PNG_WRITE_FILTER_SUPPORTED + row_buf = best_row; + mins = PNG_MAXSUM; + + /* The prediction method we use is to find which method provides the + * smallest value when summing the absolute values of the distances + * from zero, using anything >= 128 as negative numbers. This is known + * as the "minimum sum of absolute differences" heuristic. Other + * heuristics are the "weighted minimum sum of absolute differences" + * (experimental and can in theory improve compression), and the "zlib + * predictive" method (not implemented yet), which does test compressions + * of lines using different filter methods, and then chooses the + * (series of) filter(s) that give minimum compressed data size (VERY + * computationally expensive). + * + * GRR 980525: consider also + * + * (1) minimum sum of absolute differences from running average (i.e., + * keep running sum of non-absolute differences & count of bytes) + * [track dispersion, too? restart average if dispersion too large?] + * + * (1b) minimum sum of absolute differences from sliding average, probably + * with window size <= deflate window (usually 32K) + * + * (2) minimum sum of squared differences from zero or running average + * (i.e., ~ root-mean-square approach) + */ + + + /* We don't need to test the 'no filter' case if this is the only filter + * that has been chosen, as it doesn't actually do anything to the data. + */ + if ((filter_to_do & PNG_FILTER_NONE) && filter_to_do != PNG_FILTER_NONE) + { + png_bytep rp; + png_uint_32 sum = 0; + png_size_t i; + int v; + + for (i = 0, rp = row_buf + 1; i < row_bytes; i++, rp++) + { + v = *rp; + sum += (v < 128) ? v : 256 - v; + } + +#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED + if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) + { + png_uint_32 sumhi, sumlo; + int j; + sumlo = sum & PNG_LOMASK; + sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; /* Gives us some footroom */ + + /* Reduce the sum if we match any of the previous rows */ + for (j = 0; j < num_p_filters; j++) + { + if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE) + { + sumlo = (sumlo * png_ptr->filter_weights[j]) >> + PNG_WEIGHT_SHIFT; + + sumhi = (sumhi * png_ptr->filter_weights[j]) >> + PNG_WEIGHT_SHIFT; + } + } + + /* Factor in the cost of this filter (this is here for completeness, + * but it makes no sense to have a "cost" for the NONE filter, as + * it has the minimum possible computational cost - none). + */ + sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_NONE]) >> + PNG_COST_SHIFT; + + sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_NONE]) >> + PNG_COST_SHIFT; + + if (sumhi > PNG_HIMASK) + sum = PNG_MAXSUM; + + else + sum = (sumhi << PNG_HISHIFT) + sumlo; + } +#endif + mins = sum; + } + + /* Sub filter */ + if (filter_to_do == PNG_FILTER_SUB) + /* It's the only filter so no testing is needed */ + { + png_bytep rp, lp, dp; + png_size_t i; + + for (i = 0, rp = row_buf + 1, dp = png_ptr->sub_row + 1; i < bpp; + i++, rp++, dp++) + { + *dp = *rp; + } + + for (lp = row_buf + 1; i < row_bytes; + i++, rp++, lp++, dp++) + { + *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff); + } + + best_row = png_ptr->sub_row; + } + + else if (filter_to_do & PNG_FILTER_SUB) + { + png_bytep rp, dp, lp; + png_uint_32 sum = 0, lmins = mins; + png_size_t i; + int v; + +#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED + /* We temporarily increase the "minimum sum" by the factor we + * would reduce the sum of this filter, so that we can do the + * early exit comparison without scaling the sum each time. + */ + if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) + { + int j; + png_uint_32 lmhi, lmlo; + lmlo = lmins & PNG_LOMASK; + lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK; + + for (j = 0; j < num_p_filters; j++) + { + if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB) + { + lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >> + PNG_WEIGHT_SHIFT; + + lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >> + PNG_WEIGHT_SHIFT; + } + } + + lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >> + PNG_COST_SHIFT; + + lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >> + PNG_COST_SHIFT; + + if (lmhi > PNG_HIMASK) + lmins = PNG_MAXSUM; + + else + lmins = (lmhi << PNG_HISHIFT) + lmlo; + } +#endif + + for (i = 0, rp = row_buf + 1, dp = png_ptr->sub_row + 1; i < bpp; + i++, rp++, dp++) + { + v = *dp = *rp; + + sum += (v < 128) ? v : 256 - v; + } + + for (lp = row_buf + 1; i < row_bytes; + i++, rp++, lp++, dp++) + { + v = *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff); + + sum += (v < 128) ? v : 256 - v; + + if (sum > lmins) /* We are already worse, don't continue. */ + break; + } + +#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED + if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) + { + int j; + png_uint_32 sumhi, sumlo; + sumlo = sum & PNG_LOMASK; + sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; + + for (j = 0; j < num_p_filters; j++) + { + if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB) + { + sumlo = (sumlo * png_ptr->inv_filter_weights[j]) >> + PNG_WEIGHT_SHIFT; + + sumhi = (sumhi * png_ptr->inv_filter_weights[j]) >> + PNG_WEIGHT_SHIFT; + } + } + + sumlo = (sumlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >> + PNG_COST_SHIFT; + + sumhi = (sumhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >> + PNG_COST_SHIFT; + + if (sumhi > PNG_HIMASK) + sum = PNG_MAXSUM; + + else + sum = (sumhi << PNG_HISHIFT) + sumlo; + } +#endif + + if (sum < mins) + { + mins = sum; + best_row = png_ptr->sub_row; + } + } + + /* Up filter */ + if (filter_to_do == PNG_FILTER_UP) + { + png_bytep rp, dp, pp; + png_size_t i; + + for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1, + pp = prev_row + 1; i < row_bytes; + i++, rp++, pp++, dp++) + { + *dp = (png_byte)(((int)*rp - (int)*pp) & 0xff); + } + + best_row = png_ptr->up_row; + } + + else if (filter_to_do & PNG_FILTER_UP) + { + png_bytep rp, dp, pp; + png_uint_32 sum = 0, lmins = mins; + png_size_t i; + int v; + + +#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED + if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) + { + int j; + png_uint_32 lmhi, lmlo; + lmlo = lmins & PNG_LOMASK; + lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK; + + for (j = 0; j < num_p_filters; j++) + { + if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP) + { + lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >> + PNG_WEIGHT_SHIFT; + + lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >> + PNG_WEIGHT_SHIFT; + } + } + + lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_UP]) >> + PNG_COST_SHIFT; + + lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_UP]) >> + PNG_COST_SHIFT; + + if (lmhi > PNG_HIMASK) + lmins = PNG_MAXSUM; + + else + lmins = (lmhi << PNG_HISHIFT) + lmlo; + } +#endif + + for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1, + pp = prev_row + 1; i < row_bytes; i++) + { + v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff); + + sum += (v < 128) ? v : 256 - v; + + if (sum > lmins) /* We are already worse, don't continue. */ + break; + } + +#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED + if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) + { + int j; + png_uint_32 sumhi, sumlo; + sumlo = sum & PNG_LOMASK; + sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; + + for (j = 0; j < num_p_filters; j++) + { + if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP) + { + sumlo = (sumlo * png_ptr->filter_weights[j]) >> + PNG_WEIGHT_SHIFT; + + sumhi = (sumhi * png_ptr->filter_weights[j]) >> + PNG_WEIGHT_SHIFT; + } + } + + sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_UP]) >> + PNG_COST_SHIFT; + + sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_UP]) >> + PNG_COST_SHIFT; + + if (sumhi > PNG_HIMASK) + sum = PNG_MAXSUM; + + else + sum = (sumhi << PNG_HISHIFT) + sumlo; + } +#endif + + if (sum < mins) + { + mins = sum; + best_row = png_ptr->up_row; + } + } + + /* Avg filter */ + if (filter_to_do == PNG_FILTER_AVG) + { + png_bytep rp, dp, pp, lp; + png_uint_32 i; + + for (i = 0, rp = row_buf + 1, dp = png_ptr->avg_row + 1, + pp = prev_row + 1; i < bpp; i++) + { + *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff); + } + + for (lp = row_buf + 1; i < row_bytes; i++) + { + *dp++ = (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2)) + & 0xff); + } + best_row = png_ptr->avg_row; + } + + else if (filter_to_do & PNG_FILTER_AVG) + { + png_bytep rp, dp, pp, lp; + png_uint_32 sum = 0, lmins = mins; + png_size_t i; + int v; + +#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED + if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) + { + int j; + png_uint_32 lmhi, lmlo; + lmlo = lmins & PNG_LOMASK; + lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK; + + for (j = 0; j < num_p_filters; j++) + { + if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_AVG) + { + lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >> + PNG_WEIGHT_SHIFT; + + lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >> + PNG_WEIGHT_SHIFT; + } + } + + lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_AVG]) >> + PNG_COST_SHIFT; + + lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_AVG]) >> + PNG_COST_SHIFT; + + if (lmhi > PNG_HIMASK) + lmins = PNG_MAXSUM; + + else + lmins = (lmhi << PNG_HISHIFT) + lmlo; + } +#endif + + for (i = 0, rp = row_buf + 1, dp = png_ptr->avg_row + 1, + pp = prev_row + 1; i < bpp; i++) + { + v = *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff); + + sum += (v < 128) ? v : 256 - v; + } + + for (lp = row_buf + 1; i < row_bytes; i++) + { + v = *dp++ = + (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2)) & 0xff); + + sum += (v < 128) ? v : 256 - v; + + if (sum > lmins) /* We are already worse, don't continue. */ + break; + } + +#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED + if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) + { + int j; + png_uint_32 sumhi, sumlo; + sumlo = sum & PNG_LOMASK; + sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; + + for (j = 0; j < num_p_filters; j++) + { + if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE) + { + sumlo = (sumlo * png_ptr->filter_weights[j]) >> + PNG_WEIGHT_SHIFT; + + sumhi = (sumhi * png_ptr->filter_weights[j]) >> + PNG_WEIGHT_SHIFT; + } + } + + sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_AVG]) >> + PNG_COST_SHIFT; + + sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_AVG]) >> + PNG_COST_SHIFT; + + if (sumhi > PNG_HIMASK) + sum = PNG_MAXSUM; + + else + sum = (sumhi << PNG_HISHIFT) + sumlo; + } +#endif + + if (sum < mins) + { + mins = sum; + best_row = png_ptr->avg_row; + } + } + + /* Paeth filter */ + if (filter_to_do == PNG_FILTER_PAETH) + { + png_bytep rp, dp, pp, cp, lp; + png_size_t i; + + for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1, + pp = prev_row + 1; i < bpp; i++) + { + *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff); + } + + for (lp = row_buf + 1, cp = prev_row + 1; i < row_bytes; i++) + { + int a, b, c, pa, pb, pc, p; + + b = *pp++; + c = *cp++; + a = *lp++; + + p = b - c; + pc = a - c; + +#ifdef PNG_USE_ABS + pa = abs(p); + pb = abs(pc); + pc = abs(p + pc); +#else + pa = p < 0 ? -p : p; + pb = pc < 0 ? -pc : pc; + pc = (p + pc) < 0 ? -(p + pc) : p + pc; +#endif + + p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c; + + *dp++ = (png_byte)(((int)*rp++ - p) & 0xff); + } + best_row = png_ptr->paeth_row; + } + + else if (filter_to_do & PNG_FILTER_PAETH) + { + png_bytep rp, dp, pp, cp, lp; + png_uint_32 sum = 0, lmins = mins; + png_size_t i; + int v; + +#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED + if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) + { + int j; + png_uint_32 lmhi, lmlo; + lmlo = lmins & PNG_LOMASK; + lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK; + + for (j = 0; j < num_p_filters; j++) + { + if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH) + { + lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >> + PNG_WEIGHT_SHIFT; + + lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >> + PNG_WEIGHT_SHIFT; + } + } + + lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_PAETH]) >> + PNG_COST_SHIFT; + + lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_PAETH]) >> + PNG_COST_SHIFT; + + if (lmhi > PNG_HIMASK) + lmins = PNG_MAXSUM; + + else + lmins = (lmhi << PNG_HISHIFT) + lmlo; + } +#endif + + for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1, + pp = prev_row + 1; i < bpp; i++) + { + v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff); + + sum += (v < 128) ? v : 256 - v; + } + + for (lp = row_buf + 1, cp = prev_row + 1; i < row_bytes; i++) + { + int a, b, c, pa, pb, pc, p; + + b = *pp++; + c = *cp++; + a = *lp++; + +#ifndef PNG_SLOW_PAETH + p = b - c; + pc = a - c; +#ifdef PNG_USE_ABS + pa = abs(p); + pb = abs(pc); + pc = abs(p + pc); +#else + pa = p < 0 ? -p : p; + pb = pc < 0 ? -pc : pc; + pc = (p + pc) < 0 ? -(p + pc) : p + pc; +#endif + p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c; +#else /* PNG_SLOW_PAETH */ + p = a + b - c; + pa = abs(p - a); + pb = abs(p - b); + pc = abs(p - c); + + if (pa <= pb && pa <= pc) + p = a; + + else if (pb <= pc) + p = b; + + else + p = c; +#endif /* PNG_SLOW_PAETH */ + + v = *dp++ = (png_byte)(((int)*rp++ - p) & 0xff); + + sum += (v < 128) ? v : 256 - v; + + if (sum > lmins) /* We are already worse, don't continue. */ + break; + } + +#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED + if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) + { + int j; + png_uint_32 sumhi, sumlo; + sumlo = sum & PNG_LOMASK; + sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; + + for (j = 0; j < num_p_filters; j++) + { + if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH) + { + sumlo = (sumlo * png_ptr->filter_weights[j]) >> + PNG_WEIGHT_SHIFT; + + sumhi = (sumhi * png_ptr->filter_weights[j]) >> + PNG_WEIGHT_SHIFT; + } + } + + sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_PAETH]) >> + PNG_COST_SHIFT; + + sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_PAETH]) >> + PNG_COST_SHIFT; + + if (sumhi > PNG_HIMASK) + sum = PNG_MAXSUM; + + else + sum = (sumhi << PNG_HISHIFT) + sumlo; + } +#endif + + if (sum < mins) + { + best_row = png_ptr->paeth_row; + } + } +#endif /* PNG_WRITE_FILTER_SUPPORTED */ + /* Do the actual writing of the filtered row data from the chosen filter. */ + + png_write_filtered_row(png_ptr, best_row); + +#ifdef PNG_WRITE_FILTER_SUPPORTED +#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED + /* Save the type of filter we picked this time for future calculations */ + if (png_ptr->num_prev_filters > 0) + { + int j; + + for (j = 1; j < num_p_filters; j++) + { + png_ptr->prev_filters[j] = png_ptr->prev_filters[j - 1]; + } + + png_ptr->prev_filters[j] = best_row[0]; + } +#endif +#endif /* PNG_WRITE_FILTER_SUPPORTED */ +} + + +/* Do the actual writing of a previously filtered row. */ +void /* PRIVATE */ +png_write_filtered_row(png_structp png_ptr, png_bytep filtered_row) +{ + png_size_t avail; + + png_debug(1, "in png_write_filtered_row"); + + png_debug1(2, "filter = %d", filtered_row[0]); + /* Set up the zlib input buffer */ + + png_ptr->zstream.next_in = filtered_row; + png_ptr->zstream.avail_in = 0; + avail = png_ptr->row_info.rowbytes + 1; + /* Repeat until we have compressed all the data */ + do + { + int ret; /* Return of zlib */ + + /* Record the number of bytes available - zlib supports at least 65535 + * bytes at one step, depending on the size of the zlib type 'uInt', the + * maximum size zlib can write at once is ZLIB_IO_MAX (from pngpriv.h). + * Use this because on 16 bit systems 'rowbytes' can be up to 65536 (i.e. + * one more than 16 bits) and, in this case 'rowbytes+1' can overflow a + * uInt. ZLIB_IO_MAX can be safely reduced to cause zlib to be called + * with smaller chunks of data. + */ + if (png_ptr->zstream.avail_in == 0) + { + if (avail > ZLIB_IO_MAX) + { + png_ptr->zstream.avail_in = ZLIB_IO_MAX; + avail -= ZLIB_IO_MAX; + } + + else + { + /* So this will fit in the available uInt space: */ + png_ptr->zstream.avail_in = (uInt)avail; + avail = 0; + } + } + + /* Compress the data */ + ret = deflate(&png_ptr->zstream, Z_NO_FLUSH); + + /* Check for compression errors */ + if (ret != Z_OK) + { + if (png_ptr->zstream.msg != NULL) + png_error(png_ptr, png_ptr->zstream.msg); + + else + png_error(png_ptr, "zlib error"); + } + + /* See if it is time to write another IDAT */ + if (!(png_ptr->zstream.avail_out)) + { + /* Write the IDAT and reset the zlib output buffer */ + png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size); + png_ptr->zstream.next_out = png_ptr->zbuf; + png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; + } + /* Repeat until all data has been compressed */ + } while (avail > 0 || png_ptr->zstream.avail_in > 0); + + /* Swap the current and previous rows */ + if (png_ptr->prev_row != NULL) + { + png_bytep tptr; + + tptr = png_ptr->prev_row; + png_ptr->prev_row = png_ptr->row_buf; + png_ptr->row_buf = tptr; + } + + /* Finish row - updates counters and flushes zlib if last row */ + png_write_finish_row(png_ptr); + +#ifdef PNG_WRITE_FLUSH_SUPPORTED + png_ptr->flush_rows++; + + if (png_ptr->flush_dist > 0 && + png_ptr->flush_rows >= png_ptr->flush_dist) + { + png_write_flush(png_ptr); + } +#endif +} +#endif /* PNG_WRITE_SUPPORTED */ -- cgit v1.2.3