f9a51917495bc8ba8b60632219652a7b122c1190vboxsync/* pngwutil.c - utilities to write a PNG file
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * libpng version 1.2.8 - December 3, 2004
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * For conditions of distribution and use, see copyright notice in png.h
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * Copyright (c) 1998-2004 Glenn Randers-Pehrson
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync/* Place a 32-bit number into a buffer in PNG byte order. We work
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * with unsigned numbers for convenience, although one supported
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * ancillary chunk uses signed (two's complement) numbers.
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncvoid /* PRIVATE */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync#if defined(PNG_WRITE_pCAL_SUPPORTED) || defined(PNG_WRITE_oFFs_SUPPORTED)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync/* The png_save_int_32 function assumes integers are stored in two's
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * complement format. If this isn't the case, then this routine needs to
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * be modified to write data in two's complement format.
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncvoid /* PRIVATE */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync/* Place a 16-bit number into a buffer in PNG byte order.
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * The parameter is declared unsigned int, not png_uint_16,
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * just to avoid potential problems on pre-ANSI C compilers.
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncvoid /* PRIVATE */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync/* Write a PNG chunk all at once. The type is an array of ASCII characters
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * representing the chunk name. The array must be at least 4 bytes in
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * length, and does not need to be null terminated. To be safe, pass the
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * pre-defined chunk names here, and if you need a new one, define it
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * where the others are defined. The length is the length of the data.
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * All the data must be present. If that is not possible, use the
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * png_write_chunk_start(), png_write_chunk_data(), and png_write_chunk_end()
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * functions instead.
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncpng_write_chunk(png_structp png_ptr, png_bytep chunk_name,
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_chunk_start(png_ptr, chunk_name, (png_uint_32)length);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync/* Write the start of a PNG chunk. The type is the chunk type.
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * The total_length is the sum of the lengths of all the data you will be
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * passing in png_write_chunk_data().
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncpng_write_chunk_start(png_structp png_ptr, png_bytep chunk_name,
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_debug2(0, "Writing %s chunk (%lu bytes)\n", chunk_name, length);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* write the length */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* write the chunk name */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_data(png_ptr, chunk_name, (png_size_t)4);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* reset the crc and run it over the chunk name */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_calculate_crc(png_ptr, chunk_name, (png_size_t)4);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync/* Write the data of a PNG chunk started with png_write_chunk_start().
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * Note that multiple calls to this function are allowed, and that the
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * sum of the lengths from these calls *must* add up to the total_length
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * given to png_write_chunk_start().
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncpng_write_chunk_data(png_structp png_ptr, png_bytep data, png_size_t length)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* write the data, and run the CRC over it */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync/* Finish a chunk started with png_write_chunk_start(). */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* write the crc */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync/* Simple function to write the signature. If we have already written
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * the magic bytes of the signature, or more likely, the PNG stream is
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * being embedded into another stream and doesn't need its own signature,
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * we should call png_set_sig_bytes() to tell libpng how many of the
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * bytes have already been written.
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncvoid /* PRIVATE */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10};
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* write the rest of the 8 byte signature */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_data(png_ptr, &png_signature[png_ptr->sig_bytes],
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_iCCP_SUPPORTED)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * This pair of functions encapsulates the operation of (a) compressing a
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * text string, and (b) issuing it later as a series of chunk data writes.
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * The compression_state structure is shared context for these functions
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * set up by the caller in order to make the whole mess thread-safe.
f9a51917495bc8ba8b60632219652a7b122c1190vboxsynctypedef struct
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync int num_output_ptr; /* number of output pointers used */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_charpp output_ptr; /* array of pointers to output */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync/* compress given text into storage in the png_ptr structure */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncstatic int /* PRIVATE */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_charp text, png_size_t text_len, int compression,
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* we may just want to pass the text right through */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync return((int)text_len);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync sprintf(msg, "Unknown compression type %d", compression);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* We can't write the chunk until we find out how much data we have,
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * which means we need to run the compressor first and save the
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * output. This shouldn't be a problem, as the vast majority of
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * comments should be reasonable, but we will set up an array of
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * malloc'd pointers to be sure.
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * If we knew the application was well behaved, we could simplify this
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * greatly by assuming we can always malloc an output buffer large
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * enough to hold the compressed text ((1001 * text_len / 1000) + 12)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * and malloc this directly. The only time this would be a bad idea is
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * if we can't malloc more than 64K and we have 64K of random input
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * data, or if the input string is incredibly large (although this
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * wouldn't cause a failure, just a slowdown due to swapping).
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* set up the compression buffers */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_ptr->zstream.next_out = (Bytef *)png_ptr->zbuf;
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* this is the same compression loop as in png_write_row() */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* compress the data */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* error */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* check to see if we need more room */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* make sure the output array has room */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* save the data */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync comp->output_ptr[comp->num_output_ptr] = (png_charp)png_malloc(png_ptr,
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_memcpy(comp->output_ptr[comp->num_output_ptr], png_ptr->zbuf,
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* and reset the buffer */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* continue until we don't have any more to compress */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* finish the compression */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* tell zlib we are finished */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* check to see if we need more room */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* check to make sure our output array has room */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* This could be optimized to realloc() */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* save off the data */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync (png_charp)png_malloc(png_ptr, (png_uint_32)png_ptr->zbuf_size);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_memcpy(comp->output_ptr[comp->num_output_ptr], png_ptr->zbuf,
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* and reset the buffer pointers */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* we got an error */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* text length is number of buffers plus last buffer */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync text_len = png_ptr->zbuf_size * comp->num_output_ptr;
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync if (png_ptr->zstream.avail_out < png_ptr->zbuf_size)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync text_len += png_ptr->zbuf_size - (png_size_t)png_ptr->zstream.avail_out;
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync return((int)text_len);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync/* ship the compressed text out via chunk writes */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncstatic void /* PRIVATE */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncpng_write_compressed_data_out(png_structp png_ptr, compression_state *comp)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* handle the no-compression case */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_chunk_data(png_ptr, (png_bytep)comp->input,
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* write saved output buffers, if any */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_chunk_data(png_ptr,(png_bytep)comp->output_ptr[i],
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* write anything left in zbuf */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync if (png_ptr->zstream.avail_out < (png_uint_32)png_ptr->zbuf_size)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* reset zlib for another zTXt/iTXt or image data */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync/* Write the IHDR chunk, and update the png_struct with the necessary
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * information. Note that the rest of this code depends upon this
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * information being correct.
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncvoid /* PRIVATE */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncpng_write_IHDR(png_structp png_ptr, png_uint_32 width, png_uint_32 height,
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync int bit_depth, int color_type, int compression_type, int filter_type,
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_byte buf[13]; /* buffer to store the IHDR info */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* Check that we have valid input data from the application info */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync default: png_error(png_ptr,"Invalid bit depth for grayscale image");
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_error(png_ptr, "Invalid bit depth for RGB image");
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync default: png_error(png_ptr, "Invalid bit depth for paletted image");
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_error(png_ptr, "Invalid bit depth for grayscale+alpha image");
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_error(png_ptr, "Invalid bit depth for RGBA image");
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_error(png_ptr, "Invalid image color type specified");
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_warning(png_ptr, "Invalid compression type specified");
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* Write filter_method 64 (intrapixel differencing) only if
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * 2. Libpng did not write a PNG signature (this filter_method is only
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * used in PNG datastreams that are embedded in MNG datastreams) and
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * 3. The application called png_permit_mng_features with a mask that
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * included PNG_FLAG_MNG_FILTER_64 and
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * 4. The filter_method is 64 and
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * 5. The color_type is RGB or RGBA
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync !((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_warning(png_ptr, "Invalid filter type specified");
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_warning(png_ptr, "Invalid interlace type specified");
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* save off the relevent information */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_ptr->compression_type = (png_byte)compression_type;
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_ptr->pixel_depth = (png_byte)(bit_depth * png_ptr->channels);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth, width);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* set the usr info, so any transformations can modify it */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* pack the header information into the buffer */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* write the chunk */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_chunk(png_ptr, (png_bytep)png_IHDR, buf, (png_size_t)13);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* initialize zlib with PNG info */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE ||
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_STRATEGY))
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_LEVEL))
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL))
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS))
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_METHOD))
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync deflateInit2(&png_ptr->zstream, png_ptr->zlib_level,
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* libpng is not interested in zstream.data_type */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* set it to a predefined value, to avoid its evaluation inside zlib */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync/* write the palette. We are careful not to trust png_color to be in the
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * correct order for PNG, so people can redefine it to any convenient
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * structure.
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncvoid /* PRIVATE */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncpng_write_PLTE(png_structp png_ptr, png_colorp palette, png_uint_32 num_pal)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync !(png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE) &&
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_error(png_ptr, "Invalid number of colors in palette");
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_warning(png_ptr, "Invalid number of colors in palette");
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync "Ignoring request to write a PLTE chunk in grayscale PNG");
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_debug1(3, "num_palette = %d\n", png_ptr->num_palette);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_chunk_start(png_ptr, (png_bytep)png_PLTE, num_pal * 3);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync for (i = 0, pal_ptr = palette; i < num_pal; i++, pal_ptr++)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* This is a little slower but some buggy compilers need to do this instead */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync for (i = 0; i < num_pal; i++)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync/* write an IDAT chunk */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncvoid /* PRIVATE */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncpng_write_IDAT(png_structp png_ptr, png_bytep data, png_size_t length)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* Optimize the CMF field in the zlib stream. */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* This hack of the zlib stream is compliant to the stream specification. */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_ptr->compression_type == PNG_COMPRESSION_TYPE_BASE)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync unsigned int z_cmf = data[0]; /* zlib compression method and flags */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* Avoid memory underflows and multiplication overflows. */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* The conditions below are practically always satisfied;
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync however, they still must be checked. */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_uint_32 uncompressed_idat_size = png_ptr->height *
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_ptr->channels * png_ptr->bit_depth + 15) >> 3);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync unsigned int half_z_window_size = 1 << (z_cinfo + 7);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync while (uncompressed_idat_size <= half_z_window_size &&
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync data[1] += (png_byte)(0x1f - ((z_cmf << 8) + data[1]) % 0x1f);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync "Invalid zlib compression method or flags in IDAT");
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_chunk(png_ptr, (png_bytep)png_IDAT, data, length);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync/* write an IEND chunk */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncvoid /* PRIVATE */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_chunk(png_ptr, (png_bytep)png_IEND, png_bytep_NULL,
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync/* write a gAMA chunk */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncvoid /* PRIVATE */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncpng_write_gAMA(png_structp png_ptr, double file_gamma)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* file_gamma is saved in 1/100,000ths */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync igamma = (png_uint_32)(file_gamma * 100000.0 + 0.5);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_chunk(png_ptr, (png_bytep)png_gAMA, buf, (png_size_t)4);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncvoid /* PRIVATE */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncpng_write_gAMA_fixed(png_structp png_ptr, png_fixed_point file_gamma)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* file_gamma is saved in 1/100,000ths */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_chunk(png_ptr, (png_bytep)png_gAMA, buf, (png_size_t)4);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync/* write a sRGB chunk */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncvoid /* PRIVATE */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncpng_write_sRGB(png_structp png_ptr, int srgb_intent)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync "Invalid sRGB rendering intent specified");
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_chunk(png_ptr, (png_bytep)png_sRGB, buf, (png_size_t)1);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync/* write an iCCP chunk */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncvoid /* PRIVATE */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncpng_write_iCCP(png_structp png_ptr, png_charp name, int compression_type,
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync if (name == NULL || (name_len = png_check_keyword(png_ptr, name,
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_warning(png_ptr, "Empty keyword in iCCP chunk");
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_warning(png_ptr, "Unknown compression type in iCCP chunk");
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync profile_len = png_text_compress(png_ptr, profile, (png_size_t)profile_len,
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* make sure we include the NULL after the name and the compression type */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_chunk_start(png_ptr, (png_bytep)png_iCCP,
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_chunk_data(png_ptr, (png_bytep)new_name, name_len + 2);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync/* write a sPLT chunk */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncvoid /* PRIVATE */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncpng_write_sPLT(png_structp png_ptr, png_sPLT_tp spalette)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync int palette_size = entry_size * spalette->nentries;
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync if (spalette->name == NULL || (name_len = png_check_keyword(png_ptr,
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_warning(png_ptr, "Empty keyword in sPLT chunk");
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* make sure we include the NULL after the name */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_chunk_start(png_ptr, (png_bytep)png_sPLT,
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_chunk_data(png_ptr, (png_bytep)new_name, name_len + 1);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_chunk_data(png_ptr, (png_bytep)&spalette->depth, 1);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* loop through each palette entry, writing appropriately */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync for (ep = spalette->entries; ep<spalette->entries+spalette->nentries; ep++)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_chunk_data(png_ptr, entrybuf, (png_size_t)entry_size);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_chunk_data(png_ptr, entrybuf, entry_size);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync/* write the sBIT chunk */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncvoid /* PRIVATE */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncpng_write_sBIT(png_structp png_ptr, png_color_8p sbit, int color_type)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* make sure we don't depend upon the order of PNG_COLOR_8 */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync maxbits = (png_byte)(color_type==PNG_COLOR_TYPE_PALETTE ? 8 :
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_warning(png_ptr, "Invalid sBIT depth specified");
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync if (sbit->gray == 0 || sbit->gray > png_ptr->usr_bit_depth)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_warning(png_ptr, "Invalid sBIT depth specified");
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync if (sbit->alpha == 0 || sbit->alpha > png_ptr->usr_bit_depth)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_warning(png_ptr, "Invalid sBIT depth specified");
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_chunk(png_ptr, (png_bytep)png_sBIT, buf, size);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync/* write the cHRM chunk */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncvoid /* PRIVATE */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncpng_write_cHRM(png_structp png_ptr, double white_x, double white_y,
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync double red_x, double red_y, double green_x, double green_y,
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* each value is saved in 1/100,000ths */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync if (white_x < 0 || white_x > 0.8 || white_y < 0 || white_y > 0.8 ||
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_warning(png_ptr, "Invalid cHRM white point specified");
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync fprintf(stderr,"white_x=%f, white_y=%f\n",white_x, white_y);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync if (red_x < 0 || red_x > 0.8 || red_y < 0 || red_y > 0.8 ||
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_warning(png_ptr, "Invalid cHRM red point specified");
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync if (green_x < 0 || green_x > 0.8 || green_y < 0 || green_y > 0.8 ||
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_warning(png_ptr, "Invalid cHRM green point specified");
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync if (blue_x < 0 || blue_x > 0.8 || blue_y < 0 || blue_y > 0.8 ||
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_warning(png_ptr, "Invalid cHRM blue point specified");
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_chunk(png_ptr, (png_bytep)png_cHRM, buf, (png_size_t)32);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncvoid /* PRIVATE */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncpng_write_cHRM_fixed(png_structp png_ptr, png_fixed_point white_x,
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_fixed_point white_y, png_fixed_point red_x, png_fixed_point red_y,
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_fixed_point green_x, png_fixed_point green_y, png_fixed_point blue_x,
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* each value is saved in 1/100,000ths */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync if (white_x > 80000L || white_y > 80000L || white_x + white_y > 100000L)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_warning(png_ptr, "Invalid fixed cHRM white point specified");
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync fprintf(stderr,"white_x=%ld, white_y=%ld\n",white_x, white_y);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync if (red_x > 80000L || red_y > 80000L || red_x + red_y > 100000L)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_warning(png_ptr, "Invalid cHRM fixed red point specified");
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync if (green_x > 80000L || green_y > 80000L || green_x + green_y > 100000L)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_warning(png_ptr, "Invalid fixed cHRM green point specified");
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync if (blue_x > 80000L || blue_y > 80000L || blue_x + blue_y > 100000L)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_warning(png_ptr, "Invalid fixed cHRM blue point specified");
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_chunk(png_ptr, (png_bytep)png_cHRM, buf, (png_size_t)32);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync/* write the tRNS chunk */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncvoid /* PRIVATE */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncpng_write_tRNS(png_structp png_ptr, png_bytep trans, png_color_16p tran,
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync if (num_trans <= 0 || num_trans > (int)png_ptr->num_palette)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_warning(png_ptr,"Invalid number of transparent colors specified");
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* write the chunk out as it is */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_chunk(png_ptr, (png_bytep)png_tRNS, trans, (png_size_t)num_trans);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* one 16 bit value */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync "Ignoring attempt to write tRNS chunk out-of-range for bit_depth");
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_chunk(png_ptr, (png_bytep)png_tRNS, buf, (png_size_t)2);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* three 16 bit values */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync if(png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]))
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync "Ignoring attempt to write 16-bit tRNS chunk when bit_depth is 8");
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_chunk(png_ptr, (png_bytep)png_tRNS, buf, (png_size_t)6);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_warning(png_ptr, "Can't write tRNS with an alpha channel");
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync/* write the background chunk */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncvoid /* PRIVATE */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncpng_write_bKGD(png_structp png_ptr, png_color_16p back, int color_type)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync (!(png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE))) &&
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_warning(png_ptr, "Invalid background palette index");
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_chunk(png_ptr, (png_bytep)png_bKGD, buf, (png_size_t)1);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync if(png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]))
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync "Ignoring attempt to write 16-bit bKGD chunk when bit_depth is 8");
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_chunk(png_ptr, (png_bytep)png_bKGD, buf, (png_size_t)6);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync "Ignoring attempt to write bKGD chunk out-of-range for bit_depth");
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_chunk(png_ptr, (png_bytep)png_bKGD, buf, (png_size_t)2);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync/* write the histogram */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncvoid /* PRIVATE */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncpng_write_hIST(png_structp png_ptr, png_uint_16p hist, int num_hist)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_debug2(3, "num_hist = %d, num_palette = %d\n", num_hist,
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_warning(png_ptr, "Invalid number of histogram entries specified");
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_chunk_start(png_ptr, (png_bytep)png_hIST, (png_uint_32)(num_hist * 2));
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync for (i = 0; i < num_hist; i++)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED) || \
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync defined(PNG_WRITE_iCCP_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync/* Check that the tEXt or zTXt keyword is valid per PNG 1.0 specification,
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * and if invalid, correct the keyword rather than discarding the entire
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * chunk. The PNG 1.0 specification requires keywords 1-79 characters in
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * length, forbids leading or trailing whitespace, multiple internal spaces,
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * and the non-break space (0x80) from ISO 8859-1. Returns keyword length.
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * The new_key is allocated to hold the corrected keyword and must be freed
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * by the calling routine. This avoids problems with trying to write to
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * static keywords without having to have duplicate copies of the strings.
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncpng_check_keyword(png_structp png_ptr, png_charp key, png_charpp new_key)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync if (key == NULL || (key_len = png_strlen(key)) == 0)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_debug1(2, "Keyword to be checked is '%s'\n", key);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync *new_key = (png_charp)png_malloc_warn(png_ptr, (png_uint_32)(key_len + 2));
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_warning(png_ptr, "Out of memory while procesing keyword");
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* Replace non-printing characters with a blank and print a warning */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync for (kp = key, dp = *new_key; *kp != '\0'; kp++, dp++)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync if (*kp < 0x20 || (*kp > 0x7E && (png_byte)*kp < 0xA1))
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync sprintf(msg, "invalid keyword character 0x%02X", *kp);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_warning(png_ptr, "invalid character in keyword");
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* Remove any trailing white space. */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_warning(png_ptr, "trailing spaces removed from keyword");
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* Remove any leading white space. */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_warning(png_ptr, "leading spaces removed from keyword");
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_debug1(2, "Checking for multiple internal spaces in '%s'\n", kp);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* Remove multiple internal spaces. */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_warning(png_ptr, "extra interior spaces removed from keyword");
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_warning(png_ptr, "keyword length must be 1 - 79 characters");
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync/* write a tEXt chunk */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncvoid /* PRIVATE */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncpng_write_tEXt(png_structp png_ptr, png_charp key, png_charp text,
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync if (key == NULL || (key_len = png_check_keyword(png_ptr, key, &new_key))==0)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_warning(png_ptr, "Empty keyword in tEXt chunk");
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* make sure we include the 0 after the key */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_chunk_start(png_ptr, (png_bytep)png_tEXt, (png_uint_32)key_len+text_len+1);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * We leave it to the application to meet PNG-1.0 requirements on the
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * contents of the text. PNG-1.0 through PNG-1.2 discourage the use of
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * any non-Latin-1 characters except for NEWLINE. ISO PNG will forbid them.
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG.
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_chunk_data(png_ptr, (png_bytep)new_key, key_len + 1);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_chunk_data(png_ptr, (png_bytep)text, text_len);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync/* write a compressed text chunk */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncvoid /* PRIVATE */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncpng_write_zTXt(png_structp png_ptr, png_charp key, png_charp text,
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync if (key == NULL || (key_len = png_check_keyword(png_ptr, key, &new_key))==0)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_warning(png_ptr, "Empty keyword in zTXt chunk");
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync if (text == NULL || *text == '\0' || compression==PNG_TEXT_COMPRESSION_NONE)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_tEXt(png_ptr, new_key, text, (png_size_t)0);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* compute the compressed data; do it now for the length */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync text_len = png_text_compress(png_ptr, text, text_len, compression,
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* write start of chunk */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_chunk_start(png_ptr, (png_bytep)png_zTXt, (png_uint_32)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* write key */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_chunk_data(png_ptr, (png_bytep)key, key_len + 1);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* write compression */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_chunk_data(png_ptr, (png_bytep)buf, (png_size_t)1);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* write the compressed data */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* close the chunk */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync/* write an iTXt chunk */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncvoid /* PRIVATE */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncpng_write_iTXt(png_structp png_ptr, int compression, png_charp key,
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_charp lang, png_charp lang_key, png_charp text)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_size_t lang_len, key_len, lang_key_len, text_len;
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync if (key == NULL || (key_len = png_check_keyword(png_ptr, key, &new_key))==0)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_warning(png_ptr, "Empty keyword in iTXt chunk");
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync if (lang == NULL || (lang_len = png_check_keyword(png_ptr, lang, &new_lang))==0)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_warning(png_ptr, "Empty language field in iTXt chunk");
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* compute the compressed data; do it now for the length */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync text_len = png_text_compress(png_ptr, text, text_len, compression-2,
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* make sure we include the compression flag, the compression byte,
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * and the NULs after the key, lang, and lang_key parts */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_chunk_start(png_ptr, (png_bytep)png_iTXt,
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync 5 /* comp byte, comp flag, terminators for key, lang and lang_key */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * We leave it to the application to meet PNG-1.0 requirements on the
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * contents of the text. PNG-1.0 through PNG-1.2 discourage the use of
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * any non-Latin-1 characters except for NEWLINE. ISO PNG will forbid them.
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG.
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_chunk_data(png_ptr, (png_bytep)new_key, key_len + 1);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* set the compression flag */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync else /* compression == PNG_ITXT_COMPRESSION_zTXt */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* set the compression method */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_chunk_data(png_ptr, (new_lang ? (png_bytep)new_lang : cbuf), lang_len + 1);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_chunk_data(png_ptr, (lang_key ? (png_bytep)lang_key : cbuf), lang_key_len + 1);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync/* write the oFFs chunk */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncvoid /* PRIVATE */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncpng_write_oFFs(png_structp png_ptr, png_int_32 x_offset, png_int_32 y_offset,
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_warning(png_ptr, "Unrecognized unit type for oFFs chunk");
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_chunk(png_ptr, (png_bytep)png_oFFs, buf, (png_size_t)9);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync/* write the pCAL chunk (described in the PNG extensions document) */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncvoid /* PRIVATE */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncpng_write_pCAL(png_structp png_ptr, png_charp purpose, png_int_32 X0,
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_int_32 X1, int type, int nparams, png_charp units, png_charpp params)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_debug1(1, "in png_write_pCAL (%d parameters)\n", nparams);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_warning(png_ptr, "Unrecognized equation type for pCAL chunk");
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync purpose_len = png_check_keyword(png_ptr, purpose, &new_purpose) + 1;
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_debug1(3, "pCAL purpose length = %d\n", (int)purpose_len);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync units_len = png_strlen(units) + (nparams == 0 ? 0 : 1);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_debug1(3, "pCAL units length = %d\n", (int)units_len);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync params_len = (png_uint_32p)png_malloc(png_ptr, (png_uint_32)(nparams
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* Find the length of each parameter, making sure we don't count the
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync null terminator for the last parameter. */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync for (i = 0; i < nparams; i++)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync params_len[i] = png_strlen(params[i]) + (i == nparams - 1 ? 0 : 1);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_debug2(3, "pCAL parameter %d length = %lu\n", i, params_len[i]);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_debug1(3, "pCAL total length = %d\n", (int)total_len);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_chunk_start(png_ptr, (png_bytep)png_pCAL, (png_uint_32)total_len);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_chunk_data(png_ptr, (png_bytep)new_purpose, purpose_len);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_chunk_data(png_ptr, buf, (png_size_t)10);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_chunk_data(png_ptr, (png_bytep)units, (png_size_t)units_len);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync for (i = 0; i < nparams; i++)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_chunk_data(png_ptr, (png_bytep)params[i],
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync/* write the sCAL chunk */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync#if defined(PNG_FLOATING_POINT_SUPPORTED) && !defined(PNG_NO_STDIO)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncvoid /* PRIVATE */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncpng_write_sCAL(png_structp png_ptr, int unit, double width,double height)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync/* sprintf() function is not supported on WindowsCE */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync WideCharToMultiByte(CP_ACP, 0, wc_buf, -1, wbuf, 32, NULL, NULL);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync WideCharToMultiByte(CP_ACP, 0, wc_buf, -1, hbuf, 32, NULL, NULL);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync total_len = 1 + png_strlen(wbuf)+1 + png_strlen(hbuf);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_debug1(3, "sCAL total length = %d\n", (int)total_len);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_chunk_start(png_ptr, (png_bytep)png_sCAL, (png_uint_32)total_len);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_chunk_data(png_ptr, (png_bytep)&bunit, 1);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_chunk_data(png_ptr, (png_bytep)wbuf, png_strlen(wbuf)+1);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_chunk_data(png_ptr, (png_bytep)hbuf, png_strlen(hbuf));
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncvoid /* PRIVATE */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncpng_write_sCAL_s(png_structp png_ptr, int unit, png_charp width,
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync total_len = 1 + png_strlen(wbuf)+1 + png_strlen(hbuf);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_debug1(3, "sCAL total length = %d\n", total_len);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_chunk_start(png_ptr, (png_bytep)png_sCAL, (png_uint_32)total_len);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_chunk_data(png_ptr, (png_bytep)&bunit, 1);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_chunk_data(png_ptr, (png_bytep)wbuf, png_strlen(wbuf)+1);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_chunk_data(png_ptr, (png_bytep)hbuf, png_strlen(hbuf));
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync/* write the pHYs chunk */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncvoid /* PRIVATE */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncpng_write_pHYs(png_structp png_ptr, png_uint_32 x_pixels_per_unit,
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_warning(png_ptr, "Unrecognized unit type for pHYs chunk");
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_chunk(png_ptr, (png_bytep)png_pHYs, buf, (png_size_t)9);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync/* Write the tIME chunk. Use either png_convert_from_struct_tm()
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * or png_convert_from_time_t(), or fill in the structure yourself.
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncvoid /* PRIVATE */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncpng_write_tIME(png_structp png_ptr, png_timep mod_time)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_warning(png_ptr, "Invalid time specified for tIME chunk");
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_chunk(png_ptr, (png_bytep)png_tIME, buf, (png_size_t)7);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync/* initializes the row writing capability of libpng */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncvoid /* PRIVATE */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* arrays to facilitate easy interlacing - use pass (0 - 6) as index */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* start of interlace block */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* offset to next interlace block */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* start of interlace block in the y direction */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* offset to next interlace block in the y direction */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_ptr->usr_channels*png_ptr->usr_bit_depth,png_ptr->width)+1);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* set up row buffer */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_ptr->row_buf = (png_bytep)png_malloc(png_ptr, (png_uint_32)buf_size);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* set up filtering buffer, if using this filter */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* We only need to keep the previous row if we are using one of these. */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync if (png_ptr->do_filter & (PNG_FILTER_AVG | PNG_FILTER_UP | PNG_FILTER_PAETH))
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* set up previous row buffer */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_ptr->prev_row = (png_bytep)png_malloc(png_ptr, (png_uint_32)buf_size);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_ptr->paeth_row = (png_bytep )png_malloc(png_ptr,
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* if interlaced, we need to set up width and height of pass */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 -
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_ptr->usr_width = (png_ptr->width + png_pass_inc[0] - 1 -
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync/* Internal use only. Called when finished processing a row of data. */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncvoid /* PRIVATE */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* arrays to facilitate easy interlacing - use pass (0 - 6) as index */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* start of interlace block */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* offset to next interlace block */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* start of interlace block in the y direction */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* offset to next interlace block in the y direction */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* next row */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* see if we are done */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* if interlaced, go to next pass */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* loop until we find a non-zero width or height pass */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync } while (png_ptr->usr_width == 0 || png_ptr->num_rows == 0);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* reset the row above the image for the next pass */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* if we get here, we've just written the last row, so we need
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync to flush the compressor */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* tell the compressor we are done */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* check for an error */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* check to see if we need more room */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* write any extra space */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync if (png_ptr->zstream.avail_out < png_ptr->zbuf_size)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size -
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync/* Pick out the correct pixels for the interlace pass.
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * The basic idea here is to go through the row with a source
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * pointer and a destination pointer (sp and dp), and copy the
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * correct pixels for the pass. As the row gets compacted,
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * sp will always be >= dp, so we should never overwrite anything.
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * See the default: case for the easiest code to understand.
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncvoid /* PRIVATE */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncpng_do_write_interlace(png_row_infop row_info, png_bytep row, int pass)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* arrays to facilitate easy interlacing - use pass (0 - 6) as index */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* start of interlace block */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* offset to next interlace block */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* we don't have to do anything on the last pass (6) */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* each pixel depth is handled separately */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync value = (int)(*sp >> (7 - (int)(i & 0x07))) & 0x01;
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync value = (*sp >> ((3 - (int)(i & 0x03)) << 1)) & 0x03;
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync value = (*sp >> ((1 - (int)(i & 0x01)) << 2)) & 0x0f;
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* start at the beginning */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* find out how many bytes each pixel takes up */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* loop through the row, only looking at the pixels that
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* find out where the original pixel is */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* move the pixel */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* next pixel */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* set new row width */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync/* This filters the row, chooses which filter to use, if it has not already
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * been specified by the application, and then writes the row out with the
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * chosen filter.
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync#define PNG_HIMASK ((png_uint_32)(~PNG_LOMASK >> PNG_HISHIFT))
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncvoid /* PRIVATE */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncpng_write_find_filter(png_structp png_ptr, png_row_infop row_info)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync int num_p_filters = (int)png_ptr->num_prev_filters;
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* find out how many bytes offset each pixel is */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* The prediction method we use is to find which method provides the
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * smallest value when summing the absolute values of the distances
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * from zero, using anything >= 128 as negative numbers. This is known
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * as the "minimum sum of absolute differences" heuristic. Other
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * heuristics are the "weighted minimum sum of absolute differences"
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * (experimental and can in theory improve compression), and the "zlib
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * predictive" method (not implemented yet), which does test compressions
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * of lines using different filter methods, and then chooses the
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * (series of) filter(s) that give minimum compressed data size (VERY
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * computationally expensive).
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * GRR 980525: consider also
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * (1) minimum sum of absolute differences from running average (i.e.,
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * keep running sum of non-absolute differences & count of bytes)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * [track dispersion, too? restart average if dispersion too large?]
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * (1b) minimum sum of absolute differences from sliding average, probably
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * with window size <= deflate window (usually 32K)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * (2) minimum sum of squared differences from zero or running average
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * (i.e., ~ root-mean-square approach)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* We don't need to test the 'no filter' case if this is the only filter
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * that has been chosen, as it doesn't actually do anything to the data.
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync for (i = 0, rp = row_buf + 1; i < row_bytes; i++, rp++)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; /* Gives us some footroom */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* Reduce the sum if we match any of the previous rows */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync for (j = 0; j < num_p_filters; j++)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* Factor in the cost of this filter (this is here for completeness,
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * but it makes no sense to have a "cost" for the NONE filter, as
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * it has the minimum possible computational cost - none).
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_NONE]) >>
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_NONE]) >>
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* sub filter */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* it's the only filter so no testing is needed */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync for (i = 0, rp = row_buf + 1, dp = png_ptr->sub_row + 1; i < bpp;
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* We temporarily increase the "minimum sum" by the factor we
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * would reduce the sum of this filter, so that we can do the
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync * early exit comparison without scaling the sum each time.
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync for (j = 0; j < num_p_filters; j++)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync for (i = 0, rp = row_buf + 1, dp = png_ptr->sub_row + 1; i < bpp;
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync v = *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync if (sum > lmins) /* We are already worse, don't continue. */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync for (j = 0; j < num_p_filters; j++)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync sumlo = (sumlo * png_ptr->inv_filter_weights[j]) >>
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync sumhi = (sumhi * png_ptr->inv_filter_weights[j]) >>
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync sumlo = (sumlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync sumhi = (sumhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* up filter */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1,
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync for (j = 0; j < num_p_filters; j++)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_UP]) >>
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_UP]) >>
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1,
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync if (sum > lmins) /* We are already worse, don't continue. */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync for (j = 0; j < num_p_filters; j++)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_UP]) >>
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_UP]) >>
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* avg filter */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync for (i = 0, rp = row_buf + 1, dp = png_ptr->avg_row + 1,
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync *dp++ = (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2))
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync for (j = 0; j < num_p_filters; j++)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_AVG)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_AVG]) >>
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_AVG]) >>
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync for (i = 0, rp = row_buf + 1, dp = png_ptr->avg_row + 1,
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync v = *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2)) & 0xff);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync if (sum > lmins) /* We are already worse, don't continue. */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync for (j = 0; j < num_p_filters; j++)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_AVG]) >>
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_AVG]) >>
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* Paeth filter */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1,
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync for (lp = row_buf + 1, cp = prev_row + 1; i < row_bytes; i++)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync pa = p < 0 ? -p : p;
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c;
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync for (j = 0; j < num_p_filters; j++)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_PAETH]) >>
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_PAETH]) >>
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1,
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync for (lp = row_buf + 1, cp = prev_row + 1; i < row_bytes; i++)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync pa = p < 0 ? -p : p;
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c;
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync#else /* PNG_SLOW_PAETH */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync p = a + b - c;
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync#endif /* PNG_SLOW_PAETH */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync if (sum > lmins) /* We are already worse, don't continue. */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync for (j = 0; j < num_p_filters; j++)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_PAETH]) >>
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_PAETH]) >>
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* Do the actual writing of the filtered row data from the chosen filter. */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* Save the type of filter we picked this time for future calculations */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_ptr->prev_filters[j] = png_ptr->prev_filters[j - 1];
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync/* Do the actual writing of a previously filtered row. */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncvoid /* PRIVATE */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsyncpng_write_filtered_row(png_structp png_ptr, png_bytep filtered_row)
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* set up the zlib input buffer */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_ptr->zstream.avail_in = (uInt)png_ptr->row_info.rowbytes + 1;
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* repeat until we have compressed all the data */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* compress the data */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* check for compression errors */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* see if it is time to write another IDAT */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* write the IDAT and reset the zlib output buffer */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size);
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* repeat until all data has been compressed */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* swap the current and previous rows */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync /* finish row - updates counters and flushes zlib if last row */
f9a51917495bc8ba8b60632219652a7b122c1190vboxsync#endif /* PNG_WRITE_SUPPORTED */