| |
| /* pngwutil.c - utilities to write a PNG file |
| * |
| * Last changed in libpng 1.4.1 [February 25, 2010] |
| * Copyright (c) 1998-2010 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 |
| */ |
| |
| #define PNG_NO_PEDANTIC_WARNINGS |
| #include "png.h" |
| #ifdef PNG_WRITE_SUPPORTED |
| #include "pngpriv.h" |
| |
| /* 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. |
| */ |
| 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); |
| } |
| |
| /* 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_bytep chunk_name, |
| png_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_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_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 |
| { |
| char *input; /* The uncompressed input data */ |
| int input_len; /* Its length */ |
| int num_output_ptr; /* Number of output pointers used */ |
| int max_output_ptr; /* Size of output_ptr */ |
| png_charpp 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_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 = text; |
| comp->input_len = text_len; |
| return((int)text_len); |
| } |
| |
| if (compression >= PNG_TEXT_COMPRESSION_LAST) |
| { |
| #ifdef PNG_STDIO_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 */ |
| png_ptr->zstream.avail_in = (uInt)text_len; |
| png_ptr->zstream.next_in = (Bytef *)text; |
| png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; |
| png_ptr->zstream.next_out = (Bytef *)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_charpp old_ptr; |
| |
| old_ptr = comp->output_ptr; |
| comp->output_ptr = (png_charpp)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_charpp)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_charp)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_charpp old_ptr; |
| |
| old_ptr = comp->output_ptr; |
| /* This could be optimized to realloc() */ |
| comp->output_ptr = (png_charpp)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_charpp)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_charp)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, (png_bytep)comp->input, |
| (png_size_t)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, (png_bytep)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: |
| case 16: png_ptr->channels = 1; break; |
| default: png_error(png_ptr, |
| "Invalid bit depth for grayscale image"); |
| } |
| break; |
| case PNG_COLOR_TYPE_RGB: |
| if (bit_depth != 8 && bit_depth != 16) |
| 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: |
| if (bit_depth != 8 && bit_depth != 16) |
| 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_bytep)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 */ |
| /* 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_colorp palette, png_uint_32 num_pal) |
| { |
| PNG_PLTE; |
| png_uint_32 i; |
| png_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_bytep)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] != (png_byte)z_cmf) |
| { |
| data[0] = (png_byte)z_cmf; |
| data[1] &= 0xe0; |
| data[1] += (png_byte)(0x1f - ((z_cmf << 8) + data[1]) % 0x1f); |
| } |
| } |
| } |
| else |
| png_error(png_ptr, |
| "Invalid zlib compression method or flags in IDAT"); |
| } |
| |
| png_write_chunk(png_ptr, (png_bytep)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_bytep)png_IEND, NULL, |
| (png_size_t)0); |
| png_ptr->mode |= PNG_HAVE_IEND; |
| } |
| |
| #ifdef PNG_WRITE_gAMA_SUPPORTED |
| /* Write a gAMA chunk */ |
| #ifdef PNG_FLOATING_POINT_SUPPORTED |
| void /* PRIVATE */ |
| png_write_gAMA(png_structp png_ptr, double file_gamma) |
| { |
| PNG_gAMA; |
| png_uint_32 igamma; |
| png_byte buf[4]; |
| |
| png_debug(1, "in png_write_gAMA"); |
| |
| /* file_gamma is saved in 1/100,000ths */ |
| igamma = (png_uint_32)(file_gamma * 100000.0 + 0.5); |
| png_save_uint_32(buf, igamma); |
| png_write_chunk(png_ptr, (png_bytep)png_gAMA, buf, (png_size_t)4); |
| } |
| #endif |
| #ifdef PNG_FIXED_POINT_SUPPORTED |
| 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_bytep)png_gAMA, buf, (png_size_t)4); |
| } |
| #endif |
| #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_bytep)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_charp name, int compression_type, |
| png_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_bytep)profile ))<<24) | |
| ((*( (png_bytep)profile + 1))<<16) | |
| ((*( (png_bytep)profile + 2))<< 8) | |
| ((*( (png_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_bytep)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_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_bytep)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, (png_bytep)&spalette->depth, (png_size_t)1); |
| |
| /* Loop through each palette entry, writing appropriately */ |
| #ifdef PNG_POINTER_INDEXING_SUPPORTED |
| for (ep = spalette->entries; ep<spalette->entries + 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_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_bytep)png_sBIT, buf, size); |
| } |
| #endif |
| |
| #ifdef PNG_WRITE_cHRM_SUPPORTED |
| /* Write the cHRM chunk */ |
| #ifdef PNG_FLOATING_POINT_SUPPORTED |
| void /* PRIVATE */ |
| png_write_cHRM(png_structp png_ptr, double white_x, double white_y, |
| double red_x, double red_y, double green_x, double green_y, |
| double blue_x, double blue_y) |
| { |
| PNG_cHRM; |
| png_byte buf[32]; |
| |
| png_fixed_point int_white_x, int_white_y, int_red_x, int_red_y, |
| int_green_x, int_green_y, int_blue_x, int_blue_y; |
| |
| png_debug(1, "in png_write_cHRM"); |
| |
| int_white_x = (png_uint_32)(white_x * 100000.0 + 0.5); |
| int_white_y = (png_uint_32)(white_y * 100000.0 + 0.5); |
| int_red_x = (png_uint_32)(red_x * 100000.0 + 0.5); |
| int_red_y = (png_uint_32)(red_y * 100000.0 + 0.5); |
| int_green_x = (png_uint_32)(green_x * 100000.0 + 0.5); |
| int_green_y = (png_uint_32)(green_y * 100000.0 + 0.5); |
| int_blue_x = (png_uint_32)(blue_x * 100000.0 + 0.5); |
| int_blue_y = (png_uint_32)(blue_y * 100000.0 + 0.5); |
| |
| #ifdef PNG_CHECK_cHRM_SUPPORTED |
| if (png_check_cHRM_fixed(png_ptr, int_white_x, int_white_y, |
| int_red_x, int_red_y, int_green_x, int_green_y, int_blue_x, int_blue_y)) |
| #endif |
| { |
| /* Each value is saved in 1/100,000ths */ |
| |
| png_save_uint_32(buf, int_white_x); |
| png_save_uint_32(buf + 4, int_white_y); |
| |
| png_save_uint_32(buf + 8, int_red_x); |
| png_save_uint_32(buf + 12, int_red_y); |
| |
| png_save_uint_32(buf + 16, int_green_x); |
| png_save_uint_32(buf + 20, int_green_y); |
| |
| png_save_uint_32(buf + 24, int_blue_x); |
| png_save_uint_32(buf + 28, int_blue_y); |
| |
| png_write_chunk(png_ptr, (png_bytep)png_cHRM, buf, (png_size_t)32); |
| } |
| } |
| #endif |
| #ifdef PNG_FIXED_POINT_SUPPORTED |
| 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_bytep)png_cHRM, buf, (png_size_t)32); |
| } |
| } |
| #endif |
| #endif |
| |
| #ifdef PNG_WRITE_tRNS_SUPPORTED |
| /* Write the tRNS chunk */ |
| void /* PRIVATE */ |
| png_write_tRNS(png_structp png_ptr, png_bytep trans_alpha, png_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_bytep)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_bytep)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); |
| if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4])) |
| { |
| png_warning(png_ptr, |
| "Ignoring attempt to write 16-bit tRNS chunk when bit_depth is 8"); |
| return; |
| } |
| png_write_chunk(png_ptr, (png_bytep)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_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_bytep)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); |
| if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4])) |
| { |
| png_warning(png_ptr, |
| "Ignoring attempt to write 16-bit bKGD chunk when bit_depth is 8"); |
| return; |
| } |
| png_write_chunk(png_ptr, (png_bytep)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_bytep)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_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_bytep)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_charp key, png_charpp new_key) |
| { |
| png_size_t key_len; |
| 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 (kp = key, dp = *new_key; *kp != '\0'; kp++, dp++) |
| { |
| if ((png_byte)*kp < 0x20 || |
| ((png_byte)*kp > 0x7E && (png_byte)*kp < 0xA1)) |
| { |
| #ifdef PNG_STDIO_SUPPORTED |
| char msg[40]; |
| |
| png_snprintf(msg, 40, |
| "invalid keyword character 0x%02X", (png_byte)*kp); |
| png_warning(png_ptr, msg); |
| #else |
| png_warning(png_ptr, "invalid character in keyword"); |
| #endif |
| *dp = ' '; |
| } |
| else |
| { |
| *dp = *kp; |
| } |
| } |
| *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_charp key, png_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_bytep)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_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_charp key, png_charp text, |
| png_size_t text_len, int compression) |
| { |
| PNG_zTXt; |
| png_size_t key_len; |
| char buf[1]; |
| 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_bytep)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[0] = (png_byte)compression; |
| /* Write compression */ |
| png_write_chunk_data(png_ptr, (png_bytep)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_charp key, |
| png_charp lang, png_charp lang_key, png_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_bytep)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_bytep)new_lang : cbuf), |
| (png_size_t)(lang_len + 1)); |
| png_write_chunk_data(png_ptr, (lang_key ? (png_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_bytep)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_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_bytep)png_pCAL, (png_uint_32)total_len); |
| png_write_chunk_data(png_ptr, (png_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_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_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 */ |
| #if defined(PNG_FLOATING_POINT_SUPPORTED) && defined(PNG_STDIO_SUPPORTED) |
| void /* PRIVATE */ |
| png_write_sCAL(png_structp png_ptr, int unit, double width, double height) |
| { |
| PNG_sCAL; |
| char buf[64]; |
| png_size_t total_len; |
| |
| png_debug(1, "in png_write_sCAL"); |
| |
| buf[0] = (char)unit; |
| png_snprintf(buf + 1, 63, "%12.12e", width); |
| total_len = 1 + png_strlen(buf + 1) + 1; |
| png_snprintf(buf + total_len, 64-total_len, "%12.12e", height); |
| total_len += png_strlen(buf + total_len); |
| |
| png_debug1(3, "sCAL total length = %u", (unsigned int)total_len); |
| png_write_chunk(png_ptr, (png_bytep)png_sCAL, (png_bytep)buf, total_len); |
| } |
| #else |
| #ifdef PNG_FIXED_POINT_SUPPORTED |
| void /* PRIVATE */ |
| png_write_sCAL_s(png_structp png_ptr, int unit, png_charp width, |
| png_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_bytep)png_sCAL, buf, total_len); |
| } |
| #endif |
| #endif |
| #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_bytep)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_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_bytep)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_alloc_size_t)(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_size_t)(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_alloc_size_t)(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_size_t)(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_uint_32 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_uint_32 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_uint_32 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_uint_32 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_uint_32 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_uint_32 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_uint_32 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_uint_32 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_uint_32 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_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 = (uInt)png_ptr->row_info.rowbytes + 1; |
| /* Repeat until we have compressed all the data */ |
| do |
| { |
| int ret; /* Return of zlib */ |
| |
| /* 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 (png_ptr->zstream.avail_in); |
| |
| /* 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 */ |