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libpng/pngwutil.c

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1995-07-20 07:43:20 +00:00
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/* pngwutil.c - utilities to write a PNG file
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*
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* Last changed in libpng 1.2.41 [November 13, 2009]
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* Copyright (c) 1998-2009 Glenn Randers-Pehrson
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* (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
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*/
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#define PNG_INTERNAL
#include "png.h"
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#ifdef PNG_WRITE_SUPPORTED
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/* 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.
*/
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void PNGAPI
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png_save_uint_32(png_bytep buf, png_uint_32 i)
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{
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);
}
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/* The png_save_int_32 function assumes integers are stored in two's
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* complement format. If this isn't the case, then this routine needs to
* be modified to write data in two's complement format.
*/
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void PNGAPI
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png_save_int_32(png_bytep buf, png_int_32 i)
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{
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);
}
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/* 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.
*/
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void PNGAPI
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png_save_uint_16(png_bytep buf, unsigned int i)
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{
buf[0] = (png_byte)((i >> 8) & 0xff);
buf[1] = (png_byte)(i & 0xff);
}
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/* 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
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png_write_sig(png_structp png_ptr)
{
png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10};
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/* Write the rest of the 8 byte signature */
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png_write_data(png_ptr, &png_signature[png_ptr->sig_bytes],
(png_size_t)(8 - png_ptr->sig_bytes));
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if (png_ptr->sig_bytes < 3)
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png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE;
}
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/* Write a PNG chunk all at once. The type is an array of ASCII characters
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* 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.
*/
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void PNGAPI
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png_write_chunk(png_structp png_ptr, png_bytep chunk_name,
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png_bytep data, png_size_t length)
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{
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if (png_ptr == NULL)
return;
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png_write_chunk_start(png_ptr, chunk_name, (png_uint_32)length);
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png_write_chunk_data(png_ptr, data, (png_size_t)length);
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png_write_chunk_end(png_ptr);
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}
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/* Write the start of a PNG chunk. The type is the chunk type.
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* The total_length is the sum of the lengths of all the data you will be
* passing in png_write_chunk_data().
*/
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void PNGAPI
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png_write_chunk_start(png_structp png_ptr, png_bytep chunk_name,
png_uint_32 length)
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{
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png_byte buf[8];
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png_debug2(0, "Writing %s chunk, length = %lu", chunk_name,
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(unsigned long)length);
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if (png_ptr == NULL)
return;
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/* Write the length and the chunk name */
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png_save_uint_32(buf, length);
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png_memcpy(buf + 4, chunk_name, 4);
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png_write_data(png_ptr, buf, (png_size_t)8);
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/* Put the chunk name into png_ptr->chunk_name */
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png_memcpy(png_ptr->chunk_name, chunk_name, 4);
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/* Reset the crc and run it over the chunk name */
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png_reset_crc(png_ptr);
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png_calculate_crc(png_ptr, chunk_name, (png_size_t)4);
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}
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/* Write the data of a PNG chunk started with png_write_chunk_start().
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* 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().
*/
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void PNGAPI
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png_write_chunk_data(png_structp png_ptr, png_bytep data, png_size_t length)
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{
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/* Write the data, and run the CRC over it */
if (png_ptr == NULL)
return;
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if (data != NULL && length > 0)
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{
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png_write_data(png_ptr, data, length);
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/* Update the CRC after writing the data,
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* in case that the user I/O routine alters it.
*/
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png_calculate_crc(png_ptr, data, length);
}
}
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/* Finish a chunk started with png_write_chunk_start(). */
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void PNGAPI
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png_write_chunk_end(png_structp png_ptr)
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{
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png_byte buf[4];
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if (png_ptr == NULL) return;
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/* Write the crc in a single operation */
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png_save_uint_32(buf, png_ptr->crc);
png_write_data(png_ptr, buf, (png_size_t)4);
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}
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#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_iCCP_SUPPORTED)
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/* This pair of functions encapsulates the operation of (a) compressing a
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* 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
{
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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 */
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} compression_state;
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/* Compress given text into storage in the png_ptr structure */
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static int /* PRIVATE */
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png_text_compress(png_structp png_ptr,
png_charp text, png_size_t text_len, int compression,
compression_state *comp)
{
int ret;
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comp->num_output_ptr = 0;
comp->max_output_ptr = 0;
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comp->output_ptr = NULL;
comp->input = NULL;
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comp->input_len = 0;
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/* We may just want to pass the text right through */
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if (compression == PNG_TEXT_COMPRESSION_NONE)
{
comp->input = text;
comp->input_len = text_len;
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return((int)text_len);
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}
if (compression >= PNG_TEXT_COMPRESSION_LAST)
{
#if defined(PNG_STDIO_SUPPORTED) && !defined(_WIN32_WCE)
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char msg[50];
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png_snprintf(msg, 50, "Unknown compression type %d", compression);
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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).
*/
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/* Set up the compression buffers */
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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;
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/* This is the same compression loop as in png_write_row() */
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do
{
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/* Compress the data */
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ret = deflate(&png_ptr->zstream, Z_NO_FLUSH);
if (ret != Z_OK)
{
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/* Error */
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if (png_ptr->zstream.msg != NULL)
png_error(png_ptr, png_ptr->zstream.msg);
else
png_error(png_ptr, "zlib error");
}
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/* Check to see if we need more room */
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if (!(png_ptr->zstream.avail_out))
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{
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/* Make sure the output array has room */
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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,
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(png_uint_32)
(comp->max_output_ptr * png_sizeof(png_charpp)));
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png_memcpy(comp->output_ptr, old_ptr, old_max
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* png_sizeof(png_charp));
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png_free(png_ptr, old_ptr);
}
else
comp->output_ptr = (png_charpp)png_malloc(png_ptr,
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(png_uint_32)
(comp->max_output_ptr * png_sizeof(png_charp)));
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}
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/* Save the data */
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comp->output_ptr[comp->num_output_ptr] =
(png_charp)png_malloc(png_ptr,
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(png_uint_32)png_ptr->zbuf_size);
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png_memcpy(comp->output_ptr[comp->num_output_ptr], png_ptr->zbuf,
png_ptr->zbuf_size);
comp->num_output_ptr++;
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/* and reset the buffer */
png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
png_ptr->zstream.next_out = png_ptr->zbuf;
}
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/* Continue until we don't have any more to compress */
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} while (png_ptr->zstream.avail_in);
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/* Finish the compression */
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do
{
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/* Tell zlib we are finished */
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ret = deflate(&png_ptr->zstream, Z_FINISH);
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if (ret == Z_OK)
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{
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/* Check to see if we need more room */
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if (!(png_ptr->zstream.avail_out))
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{
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/* Check to make sure our output array has room */
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if (comp->num_output_ptr >= comp->max_output_ptr)
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{
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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,
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(png_uint_32)(comp->max_output_ptr *
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png_sizeof(png_charp)));
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png_memcpy(comp->output_ptr, old_ptr,
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old_max * png_sizeof(png_charp));
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png_free(png_ptr, old_ptr);
}
else
comp->output_ptr = (png_charpp)png_malloc(png_ptr,
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(png_uint_32)(comp->max_output_ptr *
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png_sizeof(png_charp)));
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}
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/* Save the data */
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comp->output_ptr[comp->num_output_ptr] =
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(png_charp)png_malloc(png_ptr,
(png_uint_32)png_ptr->zbuf_size);
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png_memcpy(comp->output_ptr[comp->num_output_ptr], png_ptr->zbuf,
png_ptr->zbuf_size);
comp->num_output_ptr++;
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/* 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)
{
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/* We got an error */
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if (png_ptr->zstream.msg != NULL)
png_error(png_ptr, png_ptr->zstream.msg);
else
png_error(png_ptr, "zlib error");
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}
} while (ret != Z_STREAM_END);
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/* Text length is number of buffers plus last buffer */
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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;
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return((int)text_len);
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}
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/* Ship the compressed text out via chunk writes */
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static void /* PRIVATE */
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png_write_compressed_data_out(png_structp png_ptr, compression_state *comp)
{
int i;
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/* Handle the no-compression case */
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if (comp->input)
{
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png_write_chunk_data(png_ptr, (png_bytep)comp->input,
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(png_size_t)comp->input_len);
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return;
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}
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/* Write saved output buffers, if any */
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for (i = 0; i < comp->num_output_ptr; i++)
{
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png_write_chunk_data(png_ptr, (png_bytep)comp->output_ptr[i],
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(png_size_t)png_ptr->zbuf_size);
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png_free(png_ptr, comp->output_ptr[i]);
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comp->output_ptr[i]=NULL;
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}
if (comp->max_output_ptr != 0)
png_free(png_ptr, comp->output_ptr);
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comp->output_ptr=NULL;
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/* Write anything left in zbuf */
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if (png_ptr->zstream.avail_out < (png_uint_32)png_ptr->zbuf_size)
png_write_chunk_data(png_ptr, png_ptr->zbuf,
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(png_size_t)(png_ptr->zbuf_size - png_ptr->zstream.avail_out));
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/* Reset zlib for another zTXt/iTXt or image data */
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deflateReset(&png_ptr->zstream);
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png_ptr->zstream.data_type = Z_BINARY;
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}
#endif
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/* Write the IHDR chunk, and update the png_struct with the necessary
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* information. Note that the rest of this code depends upon this
* information being correct.
*/
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void /* PRIVATE */
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png_write_IHDR(png_structp png_ptr, png_uint_32 width, png_uint_32 height,
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int bit_depth, int color_type, int compression_type, int filter_type,
int interlace_type)
{
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#ifdef PNG_USE_LOCAL_ARRAYS
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PNG_IHDR;
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#endif
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int ret;
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png_byte buf[13]; /* Buffer to store the IHDR info */
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png_debug(1, "in png_write_IHDR");
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/* Check that we have valid input data from the application info */
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switch (color_type)
{
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case PNG_COLOR_TYPE_GRAY:
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switch (bit_depth)
{
case 1:
case 2:
case 4:
case 8:
case 16: png_ptr->channels = 1; break;
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default: png_error(png_ptr, "Invalid bit depth for grayscale image");
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}
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break;
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case PNG_COLOR_TYPE_RGB:
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if (bit_depth != 8 && bit_depth != 16)
png_error(png_ptr, "Invalid bit depth for RGB image");
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png_ptr->channels = 3;
break;
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case PNG_COLOR_TYPE_PALETTE:
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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;
1997-05-16 07:46:07 +00:00
case PNG_COLOR_TYPE_GRAY_ALPHA:
1996-06-05 20:50:50 +00:00
if (bit_depth != 8 && bit_depth != 16)
png_error(png_ptr, "Invalid bit depth for grayscale+alpha image");
1995-07-20 07:43:20 +00:00
png_ptr->channels = 2;
break;
1997-05-16 07:46:07 +00:00
case PNG_COLOR_TYPE_RGB_ALPHA:
1996-06-05 20:50:50 +00:00
if (bit_depth != 8 && bit_depth != 16)
png_error(png_ptr, "Invalid bit depth for RGBA image");
1995-07-20 07:43:20 +00:00
png_ptr->channels = 4;
break;
1996-06-05 20:50:50 +00:00
default:
png_error(png_ptr, "Invalid image color type specified");
}
1997-05-16 07:46:07 +00:00
if (compression_type != PNG_COMPRESSION_TYPE_BASE)
1996-06-05 20:50:50 +00:00
{
png_warning(png_ptr, "Invalid compression type specified");
1997-05-16 07:46:07 +00:00
compression_type = PNG_COMPRESSION_TYPE_BASE;
1996-06-05 20:50:50 +00:00
}
2000-12-18 15:33:57 +00:00
/* 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
*/
2000-12-15 14:54:42 +00:00
if (
#ifdef PNG_MNG_FEATURES_SUPPORTED
2000-12-15 14:54:42 +00:00
!((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
2000-12-18 15:33:57 +00:00
((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE) == 0) &&
2001-05-07 19:52:45 +00:00
(color_type == PNG_COLOR_TYPE_RGB ||
2000-12-18 15:33:57 +00:00
color_type == PNG_COLOR_TYPE_RGB_ALPHA) &&
2000-12-15 14:54:42 +00:00
(filter_type == PNG_INTRAPIXEL_DIFFERENCING)) &&
#endif
filter_type != PNG_FILTER_TYPE_BASE)
1996-06-05 20:50:50 +00:00
{
png_warning(png_ptr, "Invalid filter type specified");
1997-05-16 07:46:07 +00:00
filter_type = PNG_FILTER_TYPE_BASE;
1996-06-05 20:50:50 +00:00
}
1998-01-31 03:45:12 +00:00
#ifdef PNG_WRITE_INTERLACING_SUPPORTED
1997-05-16 07:46:07 +00:00
if (interlace_type != PNG_INTERLACE_NONE &&
interlace_type != PNG_INTERLACE_ADAM7)
1996-06-05 20:50:50 +00:00
{
png_warning(png_ptr, "Invalid interlace type specified");
1997-05-16 07:46:07 +00:00
interlace_type = PNG_INTERLACE_ADAM7;
1995-07-20 07:43:20 +00:00
}
1998-01-31 03:45:12 +00:00
#else
interlace_type=PNG_INTERLACE_NONE;
#endif
1996-06-05 20:50:50 +00:00
2009-05-20 17:43:52 +00:00
/* Save the relevent information */
1996-06-05 20:50:50 +00:00
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
2000-12-15 14:54:42 +00:00
png_ptr->filter_type = (png_byte)filter_type;
2001-05-18 09:54:50 +00:00
#endif
2004-07-18 03:45:44 +00:00
png_ptr->compression_type = (png_byte)compression_type;
1996-06-05 20:50:50 +00:00
png_ptr->width = width;
png_ptr->height = height;
1996-01-26 07:38:47 +00:00
png_ptr->pixel_depth = (png_byte)(bit_depth * png_ptr->channels);
2004-08-04 11:34:52 +00:00
png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth, width);
2009-05-20 17:43:52 +00:00
/* Set the usr info, so any transformations can modify it */
1995-07-20 07:43:20 +00:00
png_ptr->usr_width = png_ptr->width;
png_ptr->usr_bit_depth = png_ptr->bit_depth;
1996-06-05 20:50:50 +00:00
png_ptr->usr_channels = png_ptr->channels;
2009-05-20 17:43:52 +00:00
/* Pack the header information into the buffer */
1996-06-05 20:50:50 +00:00
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;
1995-07-20 07:43:20 +00:00
2009-05-20 17:43:52 +00:00
/* Write the chunk */
2008-07-10 14:10:58 +00:00
png_write_chunk(png_ptr, (png_bytep)png_IHDR, buf, (png_size_t)13);
1995-09-26 10:22:39 +00:00
2009-05-20 17:43:52 +00:00
/* Initialize zlib with PNG info */
1997-01-17 07:34:35 +00:00
png_ptr->zstream.zalloc = png_zalloc;
png_ptr->zstream.zfree = png_zfree;
png_ptr->zstream.opaque = (voidpf)png_ptr;
1996-06-05 20:50:50 +00:00
if (!(png_ptr->do_filter))
1995-09-26 10:22:39 +00:00
{
1997-05-16 07:46:07 +00:00
if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE ||
png_ptr->bit_depth < 8)
1996-06-05 20:50:50 +00:00
png_ptr->do_filter = PNG_FILTER_NONE;
1995-09-26 10:22:39 +00:00
else
1996-06-05 20:50:50 +00:00
png_ptr->do_filter = PNG_ALL_FILTERS;
1995-09-26 10:22:39 +00:00
}
1996-06-05 20:50:50 +00:00
if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_STRATEGY))
1995-09-26 10:22:39 +00:00
{
1996-06-05 20:50:50 +00:00
if (png_ptr->do_filter != PNG_FILTER_NONE)
1995-09-26 10:22:39 +00:00
png_ptr->zlib_strategy = Z_FILTERED;
else
png_ptr->zlib_strategy = Z_DEFAULT_STRATEGY;
}
1996-06-05 20:50:50 +00:00
if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_LEVEL))
1995-09-26 10:22:39 +00:00
png_ptr->zlib_level = Z_DEFAULT_COMPRESSION;
1996-06-05 20:50:50 +00:00
if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL))
1995-09-26 10:22:39 +00:00
png_ptr->zlib_mem_level = 8;
1996-06-05 20:50:50 +00:00
if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS))
2004-09-04 18:25:08 +00:00
png_ptr->zlib_window_bits = 15;
1996-06-05 20:50:50 +00:00
if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_METHOD))
1995-09-26 10:22:39 +00:00
png_ptr->zlib_method = 8;
2008-03-13 02:44:46 +00:00
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");
}
1997-01-17 07:34:35 +00:00
png_ptr->zstream.next_out = png_ptr->zbuf;
png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
2004-11-13 04:04:56 +00:00
/* libpng is not interested in zstream.data_type */
2009-05-20 17:43:52 +00:00
/* Set it to a predefined value, to avoid its evaluation inside zlib */
2004-11-13 04:04:56 +00:00
png_ptr->zstream.data_type = Z_BINARY;
1995-09-26 10:22:39 +00:00
1996-06-05 20:50:50 +00:00
png_ptr->mode = PNG_HAVE_IHDR;
1995-07-20 07:43:20 +00:00
}
2009-05-20 17:43:52 +00:00
/* Write the palette. We are careful not to trust png_color to be in the
1998-06-14 19:43:31 +00:00
* correct order for PNG, so people can redefine it to any convenient
1998-01-01 13:13:13 +00:00
* structure.
*/
2000-05-06 19:09:57 +00:00
void /* PRIVATE */
1997-05-16 07:46:07 +00:00
png_write_PLTE(png_structp png_ptr, png_colorp palette, png_uint_32 num_pal)
1995-07-20 07:43:20 +00:00
{
1999-11-29 05:32:18 +00:00
#ifdef PNG_USE_LOCAL_ARRAYS
2007-09-27 00:34:29 +00:00
PNG_PLTE;
1999-11-29 05:32:18 +00:00
#endif
1997-05-16 07:46:07 +00:00
png_uint_32 i;
1996-01-26 07:38:47 +00:00
png_colorp pal_ptr;
1995-07-20 07:43:20 +00:00
png_byte buf[3];
2008-12-01 14:58:57 +00:00
png_debug(1, "in png_write_PLTE");
1999-09-17 17:27:26 +00:00
if ((
#ifdef PNG_MNG_FEATURES_SUPPORTED
2000-11-10 18:26:19 +00:00
!(png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE) &&
1999-09-17 17:27:26 +00:00
#endif
num_pal == 0) || num_pal > 256)
2001-05-07 19:52:45 +00:00
{
if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
1999-09-17 17:27:26 +00:00
{
2001-05-07 19:52:45 +00:00
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;
1996-06-05 20:50:50 +00:00
}
1997-05-16 07:46:07 +00:00
png_ptr->num_palette = (png_uint_16)num_pal;
2008-12-01 14:58:57 +00:00
png_debug1(3, "num_palette = %d", png_ptr->num_palette);
1996-06-05 20:50:50 +00:00
2008-07-10 14:10:58 +00:00
png_write_chunk_start(png_ptr, (png_bytep)png_PLTE,
(png_uint_32)(num_pal * 3));
#ifdef PNG_POINTER_INDEXING_SUPPORTED
1997-05-16 07:46:07 +00:00
for (i = 0, pal_ptr = palette; i < num_pal; i++, pal_ptr++)
1995-07-20 07:43:20 +00:00
{
buf[0] = pal_ptr->red;
buf[1] = pal_ptr->green;
buf[2] = pal_ptr->blue;
1997-05-16 07:46:07 +00:00
png_write_chunk_data(png_ptr, buf, (png_size_t)3);
1995-07-20 07:43:20 +00:00
}
2000-06-04 19:29:29 +00:00
#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
1995-07-20 07:43:20 +00:00
png_write_chunk_end(png_ptr);
1996-06-05 20:50:50 +00:00
png_ptr->mode |= PNG_HAVE_PLTE;
1995-07-20 07:43:20 +00:00
}
2009-05-20 17:43:52 +00:00
/* Write an IDAT chunk */
2000-05-06 19:09:57 +00:00
void /* PRIVATE */
1997-05-16 07:46:07 +00:00
png_write_IDAT(png_structp png_ptr, png_bytep data, png_size_t length)
1995-07-20 07:43:20 +00:00
{
1999-11-29 05:32:18 +00:00
#ifdef PNG_USE_LOCAL_ARRAYS
2007-09-27 00:34:29 +00:00
PNG_IDAT;
1999-11-29 05:32:18 +00:00
#endif
2008-12-01 14:58:57 +00:00
png_debug(1, "in png_write_IDAT");
2004-07-18 03:45:44 +00:00
2004-09-04 18:25:08 +00:00
/* 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)
{
2009-05-20 17:43:52 +00:00
/* Avoid memory underflows and multiplication overflows.
*
* The conditions below are practically always satisfied;
* however, they still must be checked.
*/
2004-09-04 18:25:08 +00:00
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");
}
2008-07-10 14:10:58 +00:00
png_write_chunk(png_ptr, (png_bytep)png_IDAT, data, length);
1996-06-05 20:50:50 +00:00
png_ptr->mode |= PNG_HAVE_IDAT;
1995-07-20 07:43:20 +00:00
}
2009-05-20 17:43:52 +00:00
/* Write an IEND chunk */
2000-05-06 19:09:57 +00:00
void /* PRIVATE */
1995-12-19 09:22:19 +00:00
png_write_IEND(png_structp png_ptr)
1995-07-20 07:43:20 +00:00
{
1999-11-29 05:32:18 +00:00
#ifdef PNG_USE_LOCAL_ARRAYS
2007-09-27 00:34:29 +00:00
PNG_IEND;
1999-11-29 05:32:18 +00:00
#endif
2008-12-01 14:58:57 +00:00
png_debug(1, "in png_write_IEND");
2008-07-10 14:10:58 +00:00
png_write_chunk(png_ptr, (png_bytep)png_IEND, png_bytep_NULL,
2001-10-25 03:01:19 +00:00
(png_size_t)0);
1997-01-17 07:34:35 +00:00
png_ptr->mode |= PNG_HAVE_IEND;
1995-07-20 07:43:20 +00:00
}
#ifdef PNG_WRITE_gAMA_SUPPORTED
2009-05-20 17:43:52 +00:00
/* Write a gAMA chunk */
1999-12-10 15:43:02 +00:00
#ifdef PNG_FLOATING_POINT_SUPPORTED
2000-05-06 19:09:57 +00:00
void /* PRIVATE */
1997-05-16 07:46:07 +00:00
png_write_gAMA(png_structp png_ptr, double file_gamma)
1995-07-20 07:43:20 +00:00
{
1999-11-29 05:32:18 +00:00
#ifdef PNG_USE_LOCAL_ARRAYS
2007-09-27 00:34:29 +00:00
PNG_gAMA;
1999-11-29 05:32:18 +00:00
#endif
1995-07-20 07:43:20 +00:00
png_uint_32 igamma;
png_byte buf[4];
2008-12-01 14:58:57 +00:00
png_debug(1, "in png_write_gAMA");
2000-02-05 05:40:16 +00:00
/* file_gamma is saved in 1/100,000ths */
1998-03-08 01:45:37 +00:00
igamma = (png_uint_32)(file_gamma * 100000.0 + 0.5);
1995-07-20 07:43:20 +00:00
png_save_uint_32(buf, igamma);
2008-07-10 14:10:58 +00:00
png_write_chunk(png_ptr, (png_bytep)png_gAMA, buf, (png_size_t)4);
1995-07-20 07:43:20 +00:00
}
1995-09-26 10:22:39 +00:00
#endif
1999-12-10 15:43:02 +00:00
#ifdef PNG_FIXED_POINT_SUPPORTED
2000-05-06 19:09:57 +00:00
void /* PRIVATE */
2000-02-05 05:40:16 +00:00
png_write_gAMA_fixed(png_structp png_ptr, png_fixed_point file_gamma)
1999-12-10 15:43:02 +00:00
{
#ifdef PNG_USE_LOCAL_ARRAYS
2007-09-27 00:34:29 +00:00
PNG_gAMA;
1999-12-10 15:43:02 +00:00
#endif
png_byte buf[4];
2008-12-01 14:58:57 +00:00
png_debug(1, "in png_write_gAMA");
2000-02-05 05:40:16 +00:00
/* file_gamma is saved in 1/100,000ths */
2001-06-23 13:03:17 +00:00
png_save_uint_32(buf, (png_uint_32)file_gamma);
2008-07-10 14:10:58 +00:00
png_write_chunk(png_ptr, (png_bytep)png_gAMA, buf, (png_size_t)4);
1999-12-10 15:43:02 +00:00
}
#endif
#endif
1995-07-20 07:43:20 +00:00
#ifdef PNG_WRITE_sRGB_SUPPORTED
2009-05-20 17:43:52 +00:00
/* Write a sRGB chunk */
2000-05-06 19:09:57 +00:00
void /* PRIVATE */
1998-01-17 04:06:18 +00:00
png_write_sRGB(png_structp png_ptr, int srgb_intent)
1998-01-01 13:13:13 +00:00
{
1999-11-29 05:32:18 +00:00
#ifdef PNG_USE_LOCAL_ARRAYS
2007-09-27 00:34:29 +00:00
PNG_sRGB;
1999-11-29 05:32:18 +00:00
#endif
1998-01-01 13:13:13 +00:00
png_byte buf[1];
2008-12-01 14:58:57 +00:00
png_debug(1, "in png_write_sRGB");
2008-07-10 14:10:58 +00:00
if (srgb_intent >= PNG_sRGB_INTENT_LAST)
1998-01-01 13:13:13 +00:00
png_warning(png_ptr,
"Invalid sRGB rendering intent specified");
1998-01-17 04:06:18 +00:00
buf[0]=(png_byte)srgb_intent;
2008-07-10 14:10:58 +00:00
png_write_chunk(png_ptr, (png_bytep)png_sRGB, buf, (png_size_t)1);
1998-01-01 13:13:13 +00:00
}
#endif
#ifdef PNG_WRITE_iCCP_SUPPORTED
2009-05-20 17:43:52 +00:00
/* Write an iCCP chunk */
2000-05-06 19:09:57 +00:00
void /* PRIVATE */
1999-12-10 15:43:02 +00:00
png_write_iCCP(png_structp png_ptr, png_charp name, int compression_type,
png_charp profile, int profile_len)
{
#ifdef PNG_USE_LOCAL_ARRAYS
2007-09-27 00:34:29 +00:00
PNG_iCCP;
1999-12-10 15:43:02 +00:00
#endif
png_size_t name_len;
png_charp new_name;
compression_state comp;
2006-10-02 18:35:48 +00:00
int embedded_profile_len = 0;
1999-12-10 15:43:02 +00:00
2008-12-01 14:58:57 +00:00
png_debug(1, "in png_write_iCCP");
2006-02-21 04:09:05 +00:00
comp.num_output_ptr = 0;
comp.max_output_ptr = 0;
comp.output_ptr = NULL;
comp.input = NULL;
comp.input_len = 0;
2008-12-05 17:38:53 +00:00
if ((name_len = png_check_keyword(png_ptr, name,
1999-12-10 15:43:02 +00:00
&new_name)) == 0)
return;
2000-12-28 13:50:05 +00:00
if (compression_type != PNG_COMPRESSION_TYPE_BASE)
2000-03-21 11:13:06 +00:00
png_warning(png_ptr, "Unknown compression type in iCCP chunk");
1999-12-10 15:43:02 +00:00
2000-06-24 12:42:42 +00:00
if (profile == NULL)
1999-12-10 15:43:02 +00:00
profile_len = 0;
2006-10-02 18:35:48 +00:00
if (profile_len > 3)
2006-12-05 02:04:02 +00:00
embedded_profile_len =
2008-07-10 14:10:58 +00:00
((*( (png_bytep)profile ))<<24) |
((*( (png_bytep)profile + 1))<<16) |
((*( (png_bytep)profile + 2))<< 8) |
((*( (png_bytep)profile + 3)) );
2006-10-02 18:35:48 +00:00
if (embedded_profile_len < 0)
{
png_warning(png_ptr,
"Embedded profile length in iCCP chunk is negative");
png_free(png_ptr, new_name);
return;
}
2006-10-02 18:35:48 +00:00
if (profile_len < embedded_profile_len)
2008-07-10 14:10:58 +00:00
{
png_warning(png_ptr,
"Embedded profile length too large in iCCP chunk");
2009-04-06 01:17:23 +00:00
png_free(png_ptr, new_name);
2008-07-10 14:10:58 +00:00
return;
}
2006-10-02 18:35:48 +00:00
if (profile_len > embedded_profile_len)
2008-07-10 14:10:58 +00:00
{
png_warning(png_ptr,
"Truncating profile to actual length in iCCP chunk");
profile_len = embedded_profile_len;
}
2006-10-02 18:35:48 +00:00
1999-12-10 15:43:02 +00:00
if (profile_len)
2008-07-10 14:10:58 +00:00
profile_len = png_text_compress(png_ptr, profile,
(png_size_t)profile_len, PNG_COMPRESSION_TYPE_BASE, &comp);
1999-12-10 15:43:02 +00:00
2009-05-20 17:43:52 +00:00
/* Make sure we include the NULL after the name and the compression type */
2008-07-10 14:10:58 +00:00
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));
1999-12-10 15:43:02 +00:00
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
2009-05-20 17:43:52 +00:00
/* Write a sPLT chunk */
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void /* PRIVATE */
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png_write_sPLT(png_structp png_ptr, png_sPLT_tp spalette)
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{
#ifdef PNG_USE_LOCAL_ARRAYS
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PNG_sPLT;
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#endif
png_size_t name_len;
png_charp new_name;
png_byte entrybuf[10];
int entry_size = (spalette->depth == 8 ? 6 : 10);
int palette_size = entry_size * spalette->nentries;
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png_sPLT_entryp ep;
#ifndef PNG_POINTER_INDEXING_SUPPORTED
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int i;
#endif
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png_debug(1, "in png_write_sPLT");
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if ((name_len = png_check_keyword(png_ptr,spalette->name, &new_name))==0)
return;
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/* Make sure we include the NULL after the name */
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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);
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/* Loop through each palette entry, writing appropriately */
#ifdef PNG_POINTER_INDEXING_SUPPORTED
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for (ep = spalette->entries; ep<spalette->entries + spalette->nentries; ep++)
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{
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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);
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}
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#else
ep=spalette->entries;
for (i=0; i>spalette->nentries; i++)
{
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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);
}
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png_write_chunk_data(png_ptr, entrybuf, (png_size_t)entry_size);
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}
#endif
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png_write_chunk_end(png_ptr);
png_free(png_ptr, new_name);
}
#endif
#ifdef PNG_WRITE_sBIT_SUPPORTED
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/* Write the sBIT chunk */
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void /* PRIVATE */
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png_write_sBIT(png_structp png_ptr, png_color_8p sbit, int color_type)
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{
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#ifdef PNG_USE_LOCAL_ARRAYS
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PNG_sBIT;
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#endif
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png_byte buf[4];
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png_size_t size;
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png_debug(1, "in png_write_sBIT");
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/* Make sure we don't depend upon the order of PNG_COLOR_8 */
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if (color_type & PNG_COLOR_MASK_COLOR)
{
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png_byte maxbits;
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maxbits = (png_byte)(color_type==PNG_COLOR_TYPE_PALETTE ? 8 :
png_ptr->usr_bit_depth);
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if (sbit->red == 0 || sbit->red > maxbits ||
sbit->green == 0 || sbit->green > maxbits ||
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sbit->blue == 0 || sbit->blue > maxbits)
{
png_warning(png_ptr, "Invalid sBIT depth specified");
return;
}
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buf[0] = sbit->red;
buf[1] = sbit->green;
buf[2] = sbit->blue;
size = 3;
}
else
{
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if (sbit->gray == 0 || sbit->gray > png_ptr->usr_bit_depth)
{
png_warning(png_ptr, "Invalid sBIT depth specified");
return;
}
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buf[0] = sbit->gray;
size = 1;
}
if (color_type & PNG_COLOR_MASK_ALPHA)
{
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if (sbit->alpha == 0 || sbit->alpha > png_ptr->usr_bit_depth)
{
png_warning(png_ptr, "Invalid sBIT depth specified");
return;
}
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buf[size++] = sbit->alpha;
}
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png_write_chunk(png_ptr, (png_bytep)png_sBIT, buf, size);
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}
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#endif
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#ifdef PNG_WRITE_cHRM_SUPPORTED
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/* Write the cHRM chunk */
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#ifdef PNG_FLOATING_POINT_SUPPORTED
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void /* PRIVATE */
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png_write_cHRM(png_structp png_ptr, double white_x, double white_y,
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double red_x, double red_y, double green_x, double green_y,
double blue_x, double blue_y)
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{
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#ifdef PNG_USE_LOCAL_ARRAYS
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PNG_cHRM;
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#endif
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png_byte buf[32];
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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;
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png_debug(1, "in png_write_cHRM");
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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);
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#ifdef PNG_CHECK_cHRM_SUPPORTED
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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
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{
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/* Each value is saved in 1/100,000ths */
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png_save_uint_32(buf, int_white_x);
png_save_uint_32(buf + 4, int_white_y);
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png_save_uint_32(buf + 8, int_red_x);
png_save_uint_32(buf + 12, int_red_y);
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png_save_uint_32(buf + 16, int_green_x);
png_save_uint_32(buf + 20, int_green_y);
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png_save_uint_32(buf + 24, int_blue_x);
png_save_uint_32(buf + 28, int_blue_y);
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png_write_chunk(png_ptr, (png_bytep)png_cHRM, buf, (png_size_t)32);
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}
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}
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#endif
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#ifdef PNG_FIXED_POINT_SUPPORTED
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void /* PRIVATE */
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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)
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{
#ifdef PNG_USE_LOCAL_ARRAYS
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PNG_cHRM;
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#endif
png_byte buf[32];
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png_debug(1, "in png_write_cHRM");
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/* Each value is saved in 1/100,000ths */
#ifdef PNG_CHECK_cHRM_SUPPORTED
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if (png_check_cHRM_fixed(png_ptr, white_x, white_y, red_x, red_y,
green_x, green_y, blue_x, blue_y))
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#endif
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{
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png_save_uint_32(buf, (png_uint_32)white_x);
png_save_uint_32(buf + 4, (png_uint_32)white_y);
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png_save_uint_32(buf + 8, (png_uint_32)red_x);
png_save_uint_32(buf + 12, (png_uint_32)red_y);
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png_save_uint_32(buf + 16, (png_uint_32)green_x);
png_save_uint_32(buf + 20, (png_uint_32)green_y);
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png_save_uint_32(buf + 24, (png_uint_32)blue_x);
png_save_uint_32(buf + 28, (png_uint_32)blue_y);
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png_write_chunk(png_ptr, (png_bytep)png_cHRM, buf, (png_size_t)32);
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}
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}
#endif
#endif
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#ifdef PNG_WRITE_tRNS_SUPPORTED
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/* Write the tRNS chunk */
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void /* PRIVATE */
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png_write_tRNS(png_structp png_ptr, png_bytep trans, png_color_16p tran,
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int num_trans, int color_type)
{
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#ifdef PNG_USE_LOCAL_ARRAYS
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PNG_tRNS;
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#endif
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png_byte buf[6];
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png_debug(1, "in png_write_tRNS");
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if (color_type == PNG_COLOR_TYPE_PALETTE)
{
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if (num_trans <= 0 || num_trans > (int)png_ptr->num_palette)
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{
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png_warning(png_ptr, "Invalid number of transparent colors specified");
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return;
}
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/* Write the chunk out as it is */
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png_write_chunk(png_ptr, (png_bytep)png_tRNS, trans,
(png_size_t)num_trans);
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}
else if (color_type == PNG_COLOR_TYPE_GRAY)
{
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/* One 16 bit value */
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if (tran->gray >= (1 << png_ptr->bit_depth))
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{
png_warning(png_ptr,
"Ignoring attempt to write tRNS chunk out-of-range for bit_depth");
return;
}
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png_save_uint_16(buf, tran->gray);
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png_write_chunk(png_ptr, (png_bytep)png_tRNS, buf, (png_size_t)2);
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}
else if (color_type == PNG_COLOR_TYPE_RGB)
{
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/* Three 16 bit values */
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png_save_uint_16(buf, tran->red);
png_save_uint_16(buf + 2, tran->green);
png_save_uint_16(buf + 4, tran->blue);
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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);
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}
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else
{
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png_warning(png_ptr, "Can't write tRNS with an alpha channel");
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}
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}
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#endif
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#ifdef PNG_WRITE_bKGD_SUPPORTED
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/* Write the background chunk */
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void /* PRIVATE */
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png_write_bKGD(png_structp png_ptr, png_color_16p back, int color_type)
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{
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#ifdef PNG_USE_LOCAL_ARRAYS
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PNG_bKGD;
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#endif
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png_byte buf[6];
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png_debug(1, "in png_write_bKGD");
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if (color_type == PNG_COLOR_TYPE_PALETTE)
{
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if (
#ifdef PNG_MNG_FEATURES_SUPPORTED
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(png_ptr->num_palette ||
(!(png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE))) &&
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#endif
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back->index >= png_ptr->num_palette)
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{
png_warning(png_ptr, "Invalid background palette index");
return;
}
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buf[0] = back->index;
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png_write_chunk(png_ptr, (png_bytep)png_bKGD, buf, (png_size_t)1);
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}
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);
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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);
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}
else
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{
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if (back->gray >= (1 << png_ptr->bit_depth))
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{
png_warning(png_ptr,
"Ignoring attempt to write bKGD chunk out-of-range for bit_depth");
return;
}
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png_save_uint_16(buf, back->gray);
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png_write_chunk(png_ptr, (png_bytep)png_bKGD, buf, (png_size_t)2);
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}
}
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#endif
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#ifdef PNG_WRITE_hIST_SUPPORTED
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/* Write the histogram */
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void /* PRIVATE */
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png_write_hIST(png_structp png_ptr, png_uint_16p hist, int num_hist)
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{
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#ifdef PNG_USE_LOCAL_ARRAYS
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PNG_hIST;
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#endif
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int i;
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png_byte buf[3];
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png_debug(1, "in png_write_hIST");
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if (num_hist > (int)png_ptr->num_palette)
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{
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png_debug2(3, "num_hist = %d, num_palette = %d", num_hist,
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png_ptr->num_palette);
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png_warning(png_ptr, "Invalid number of histogram entries specified");
return;
}
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png_write_chunk_start(png_ptr, (png_bytep)png_hIST,
(png_uint_32)(num_hist * 2));
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for (i = 0; i < num_hist; i++)
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{
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png_save_uint_16(buf, hist[i]);
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png_write_chunk_data(png_ptr, buf, (png_size_t)2);
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}
png_write_chunk_end(png_ptr);
}
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#endif
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#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED) || \
defined(PNG_WRITE_iCCP_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
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/* 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.
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*
* 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.
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*/
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png_size_t /* PRIVATE */
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png_check_keyword(png_structp png_ptr, png_charp key, png_charpp new_key)
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{
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png_size_t key_len;
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png_charp kp, dp;
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int kflag;
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int kwarn=0;
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png_debug(1, "in png_check_keyword");
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*new_key = NULL;
if (key == NULL || (key_len = png_strlen(key)) == 0)
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{
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png_warning(png_ptr, "zero length keyword");
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return ((png_size_t)0);
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}
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png_debug1(2, "Keyword to be checked is '%s'", key);
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*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);
}
2001-05-14 14:20:53 +00:00
1997-05-16 07:46:07 +00:00
/* Replace non-printing characters with a blank and print a warning */
for (kp = key, dp = *new_key; *kp != '\0'; kp++, dp++)
1997-01-17 07:34:35 +00:00
{
2007-05-20 03:12:32 +00:00
if ((png_byte)*kp < 0x20 ||
((png_byte)*kp > 0x7E && (png_byte)*kp < 0xA1))
1997-05-16 07:46:07 +00:00
{
#if defined(PNG_STDIO_SUPPORTED) && !defined(_WIN32_WCE)
1997-05-16 07:46:07 +00:00
char msg[40];
1997-01-17 07:34:35 +00:00
2007-05-21 02:40:52 +00:00
png_snprintf(msg, 40,
"invalid keyword character 0x%02X", (png_byte)*kp);
2000-12-01 15:23:06 +00:00
png_warning(png_ptr, msg);
1998-01-04 04:40:55 +00:00
#else
2000-12-01 15:23:06 +00:00
png_warning(png_ptr, "invalid character in keyword");
1998-01-04 04:40:55 +00:00
#endif
1997-05-16 07:46:07 +00:00
*dp = ' ';
}
else
{
*dp = *kp;
}
1997-01-17 07:34:35 +00:00
}
1997-05-16 07:46:07 +00:00
*dp = '\0';
1997-01-17 07:34:35 +00:00
1997-05-16 07:46:07 +00:00
/* Remove any trailing white space. */
kp = *new_key + key_len - 1;
if (*kp == ' ')
1997-01-17 07:34:35 +00:00
{
2000-12-01 15:23:06 +00:00
png_warning(png_ptr, "trailing spaces removed from keyword");
1997-05-16 07:46:07 +00:00
while (*kp == ' ')
{
2009-05-20 17:43:52 +00:00
*(kp--) = '\0';
key_len--;
1997-05-16 07:46:07 +00:00
}
1997-01-17 07:34:35 +00:00
}
/* Remove any leading white space. */
1997-05-16 07:46:07 +00:00
kp = *new_key;
if (*kp == ' ')
1997-01-17 07:34:35 +00:00
{
2000-12-01 15:23:06 +00:00
png_warning(png_ptr, "leading spaces removed from keyword");
1997-05-16 07:46:07 +00:00
while (*kp == ' ')
{
2009-05-20 17:43:52 +00:00
kp++;
key_len--;
1997-05-16 07:46:07 +00:00
}
1997-01-17 07:34:35 +00:00
}
2008-12-01 14:58:57 +00:00
png_debug1(2, "Checking for multiple internal spaces in '%s'", kp);
1997-05-16 07:46:07 +00:00
/* Remove multiple internal spaces. */
for (kflag = 0, dp = *new_key; *kp != '\0'; kp++)
1997-01-17 07:34:35 +00:00
{
1997-05-16 07:46:07 +00:00
if (*kp == ' ' && kflag == 0)
1997-01-17 07:34:35 +00:00
{
1997-05-16 07:46:07 +00:00
*(dp++) = *kp;
kflag = 1;
1997-01-17 07:34:35 +00:00
}
1997-05-16 07:46:07 +00:00
else if (*kp == ' ')
1997-01-17 07:34:35 +00:00
{
key_len--;
2000-12-01 15:23:06 +00:00
kwarn=1;
1997-01-17 07:34:35 +00:00
}
else
{
1997-05-16 07:46:07 +00:00
*(dp++) = *kp;
kflag = 0;
1997-01-17 07:34:35 +00:00
}
}
1997-05-16 07:46:07 +00:00
*dp = '\0';
2008-07-10 14:10:58 +00:00
if (kwarn)
2000-12-01 15:23:06 +00:00
png_warning(png_ptr, "extra interior spaces removed from keyword");
1997-01-17 07:34:35 +00:00
if (key_len == 0)
1997-05-16 07:46:07 +00:00
{
1999-10-23 13:39:18 +00:00
png_free(png_ptr, *new_key);
2008-07-25 13:38:43 +00:00
*new_key=NULL;
2000-12-01 15:23:06 +00:00
png_warning(png_ptr, "Zero length keyword");
1997-05-16 07:46:07 +00:00
}
if (key_len > 79)
{
2000-12-01 15:23:06 +00:00
png_warning(png_ptr, "keyword length must be 1 - 79 characters");
2008-11-27 12:44:23 +00:00
(*new_key)[79] = '\0';
1997-05-16 07:46:07 +00:00
key_len = 79;
}
1997-01-17 07:34:35 +00:00
1998-02-01 02:07:59 +00:00
return (key_len);
1997-01-17 07:34:35 +00:00
}
#endif
#ifdef PNG_WRITE_tEXt_SUPPORTED
2009-05-20 17:43:52 +00:00
/* Write a tEXt chunk */
2000-05-06 19:09:57 +00:00
void /* PRIVATE */
1995-12-19 09:22:19 +00:00
png_write_tEXt(png_structp png_ptr, png_charp key, png_charp text,
1997-05-16 07:46:07 +00:00
png_size_t text_len)
1995-07-20 07:43:20 +00:00
{
1999-11-29 05:32:18 +00:00
#ifdef PNG_USE_LOCAL_ARRAYS
2007-09-27 00:34:29 +00:00
PNG_tEXt;
1999-11-29 05:32:18 +00:00
#endif
1997-05-16 07:46:07 +00:00
png_size_t key_len;
1998-01-01 13:13:13 +00:00
png_charp new_key;
1997-05-16 07:46:07 +00:00
2008-12-01 14:58:57 +00:00
png_debug(1, "in png_write_tEXt");
2008-12-05 17:38:53 +00:00
if ((key_len = png_check_keyword(png_ptr, key, &new_key))==0)
1996-06-05 20:50:50 +00:00
return;
1997-05-16 07:46:07 +00:00
if (text == NULL || *text == '\0')
1997-01-17 07:34:35 +00:00
text_len = 0;
2000-02-05 05:40:16 +00:00
else
text_len = png_strlen(text);
1997-01-17 07:34:35 +00:00
2009-05-20 17:43:52 +00:00
/* Make sure we include the 0 after the key */
2008-07-10 14:10:58 +00:00
png_write_chunk_start(png_ptr, (png_bytep)png_tEXt,
(png_uint_32)(key_len + text_len + 1));
1999-09-17 17:27:26 +00:00
/*
* 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.
1999-12-10 15:43:02 +00:00
* The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG.
1999-09-17 17:27:26 +00:00
*/
2008-07-10 14:10:58 +00:00
png_write_chunk_data(png_ptr, (png_bytep)new_key,
(png_size_t)(key_len + 1));
1997-01-17 07:34:35 +00:00
if (text_len)
2008-07-10 14:10:58 +00:00
png_write_chunk_data(png_ptr, (png_bytep)text, (png_size_t)text_len);
1997-01-17 07:34:35 +00:00
1995-07-20 07:43:20 +00:00
png_write_chunk_end(png_ptr);
1997-05-16 07:46:07 +00:00
png_free(png_ptr, new_key);
1995-07-20 07:43:20 +00:00
}
1995-09-26 10:22:39 +00:00
#endif
1995-07-20 07:43:20 +00:00
#ifdef PNG_WRITE_zTXt_SUPPORTED
2009-05-20 17:43:52 +00:00
/* Write a compressed text chunk */
2000-05-06 19:09:57 +00:00
void /* PRIVATE */
1995-12-19 09:22:19 +00:00
png_write_zTXt(png_structp png_ptr, png_charp key, png_charp text,
1997-05-16 07:46:07 +00:00
png_size_t text_len, int compression)
1995-07-20 07:43:20 +00:00
{
1999-11-29 05:32:18 +00:00
#ifdef PNG_USE_LOCAL_ARRAYS
2007-09-27 00:34:29 +00:00
PNG_zTXt;
1999-11-29 05:32:18 +00:00
#endif
1997-05-16 07:46:07 +00:00
png_size_t key_len;
1995-07-20 07:43:20 +00:00
char buf[1];
1998-01-01 13:13:13 +00:00
png_charp new_key;
1999-12-10 15:43:02 +00:00
compression_state comp;
1995-07-20 07:43:20 +00:00
2008-12-01 14:58:57 +00:00
png_debug(1, "in png_write_zTXt");
1997-05-16 07:46:07 +00:00
2006-02-21 04:09:05 +00:00
comp.num_output_ptr = 0;
comp.max_output_ptr = 0;
comp.output_ptr = NULL;
comp.input = NULL;
comp.input_len = 0;
2008-12-05 17:38:53 +00:00
if ((key_len = png_check_keyword(png_ptr, key, &new_key))==0)
1997-05-16 07:46:07 +00:00
{
2008-07-10 14:10:58 +00:00
png_free(png_ptr, new_key);
1996-06-05 20:50:50 +00:00
return;
1997-05-16 07:46:07 +00:00
}
1997-01-17 07:34:35 +00:00
1997-05-16 07:46:07 +00:00
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;
}
2000-02-05 05:40:16 +00:00
text_len = png_strlen(text);
2009-05-20 17:43:52 +00:00
/* Compute the compressed data; do it now for the length */
2000-05-01 14:31:54 +00:00
text_len = png_text_compress(png_ptr, text, text_len, compression,
&comp);
1995-07-20 07:43:20 +00:00
2009-05-20 17:43:52 +00:00
/* Write start of chunk */
2008-07-10 14:10:58 +00:00
png_write_chunk_start(png_ptr, (png_bytep)png_zTXt,
(png_uint_32)(key_len+text_len + 2));
2009-05-20 17:43:52 +00:00
/* Write key */
2008-07-10 14:10:58 +00:00
png_write_chunk_data(png_ptr, (png_bytep)new_key,
(png_size_t)(key_len + 1));
2007-05-20 03:12:32 +00:00
png_free(png_ptr, new_key);
1999-12-10 15:43:02 +00:00
buf[0] = (png_byte)compression;
2009-05-20 17:43:52 +00:00
/* Write compression */
1999-12-10 15:43:02 +00:00
png_write_chunk_data(png_ptr, (png_bytep)buf, (png_size_t)1);
2009-05-20 17:43:52 +00:00
/* Write the compressed data */
1999-12-10 15:43:02 +00:00
png_write_compressed_data_out(png_ptr, &comp);
1995-09-26 10:22:39 +00:00
2009-05-20 17:43:52 +00:00
/* Close the chunk */
1999-12-10 15:43:02 +00:00
png_write_chunk_end(png_ptr);
}
#endif
1996-01-26 07:38:47 +00:00
#ifdef PNG_WRITE_iTXt_SUPPORTED
2009-05-20 17:43:52 +00:00
/* Write an iTXt chunk */
2000-05-06 19:09:57 +00:00
void /* PRIVATE */
1999-12-10 15:43:02 +00:00
png_write_iTXt(png_structp png_ptr, int compression, png_charp key,
2000-02-05 05:40:16 +00:00
png_charp lang, png_charp lang_key, png_charp text)
1999-12-10 15:43:02 +00:00
{
#ifdef PNG_USE_LOCAL_ARRAYS
2007-09-27 00:34:29 +00:00
PNG_iTXt;
1999-12-10 15:43:02 +00:00
#endif
2000-02-05 05:40:16 +00:00
png_size_t lang_len, key_len, lang_key_len, text_len;
2008-12-05 17:38:53 +00:00
png_charp new_lang;
png_charp new_key = NULL;
1999-12-10 15:43:02 +00:00
png_byte cbuf[2];
compression_state comp;
1995-07-20 07:43:20 +00:00
2008-12-01 14:58:57 +00:00
png_debug(1, "in png_write_iTXt");
1995-07-20 07:43:20 +00:00
2006-02-21 04:09:05 +00:00
comp.num_output_ptr = 0;
comp.max_output_ptr = 0;
comp.output_ptr = NULL;
comp.input = NULL;
2008-12-05 17:38:53 +00:00
if ((key_len = png_check_keyword(png_ptr, key, &new_key))==0)
1999-12-10 15:43:02 +00:00
return;
2008-12-05 17:38:53 +00:00
if ((lang_len = png_check_keyword(png_ptr, lang, &new_lang))==0)
1999-12-10 15:43:02 +00:00
{
2000-02-05 05:40:16 +00:00
png_warning(png_ptr, "Empty language field in iTXt chunk");
2002-03-26 00:49:08 +00:00
new_lang = NULL;
2004-07-18 03:45:44 +00:00
lang_len = 0;
1999-12-10 15:43:02 +00:00
}
1995-09-26 10:22:39 +00:00
2002-03-26 00:49:08 +00:00
if (lang_key == NULL)
2009-05-20 17:43:52 +00:00
lang_key_len = 0;
2002-03-26 00:49:08 +00:00
else
2009-05-20 17:43:52 +00:00
lang_key_len = png_strlen(lang_key);
2002-03-26 00:49:08 +00:00
if (text == NULL)
1999-12-10 15:43:02 +00:00
text_len = 0;
2002-03-26 00:49:08 +00:00
else
2009-05-20 17:43:52 +00:00
text_len = png_strlen(text);
1996-01-26 07:38:47 +00:00
2009-05-20 17:43:52 +00:00
/* Compute the compressed data; do it now for the length */
2000-05-01 14:31:54 +00:00
text_len = png_text_compress(png_ptr, text, text_len, compression-2,
&comp);
1996-01-26 07:38:47 +00:00
2002-03-26 00:49:08 +00:00
2009-05-20 17:43:52 +00:00
/* Make sure we include the compression flag, the compression byte,
2000-02-05 05:40:16 +00:00
* and the NULs after the key, lang, and lang_key parts */
1995-07-20 07:43:20 +00:00
2008-07-10 14:10:58 +00:00
png_write_chunk_start(png_ptr, (png_bytep)png_iTXt,
2000-02-05 05:40:16 +00:00
(png_uint_32)(
5 /* comp byte, comp flag, terminators for key, lang and lang_key */
+ key_len
+ lang_len
+ lang_key_len
+ text_len));
1995-07-20 07:43:20 +00:00
2009-05-20 17:43:52 +00:00
/* We leave it to the application to meet PNG-1.0 requirements on the
1999-12-10 15:43:02 +00:00
* 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.
*/
2008-07-10 14:10:58 +00:00
png_write_chunk_data(png_ptr, (png_bytep)new_key,
(png_size_t)(key_len + 1));
2000-02-05 05:40:16 +00:00
2009-05-20 17:43:52 +00:00
/* Set the compression flag */
2000-02-05 05:40:16 +00:00
if (compression == PNG_ITXT_COMPRESSION_NONE || \
compression == PNG_TEXT_COMPRESSION_NONE)
cbuf[0] = 0;
else /* compression == PNG_ITXT_COMPRESSION_zTXt */
cbuf[0] = 1;
2009-05-20 17:43:52 +00:00
/* Set the compression method */
2000-02-05 05:40:16 +00:00
cbuf[1] = 0;
2008-07-10 14:10:58 +00:00
png_write_chunk_data(png_ptr, cbuf, (png_size_t)2);
2000-02-05 05:40:16 +00:00
2002-03-26 00:49:08 +00:00
cbuf[0] = 0;
2008-07-10 14:10:58 +00:00
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));
1999-12-10 15:43:02 +00:00
png_write_compressed_data_out(png_ptr, &comp);
1995-07-20 07:43:20 +00:00
png_write_chunk_end(png_ptr);
1999-12-10 15:43:02 +00:00
png_free(png_ptr, new_key);
2008-04-14 14:26:03 +00:00
png_free(png_ptr, new_lang);
1995-07-20 07:43:20 +00:00
}
1995-09-26 10:22:39 +00:00
#endif
1995-07-20 07:43:20 +00:00
#ifdef PNG_WRITE_oFFs_SUPPORTED
2009-05-20 17:43:52 +00:00
/* Write the oFFs chunk */
2000-05-06 19:09:57 +00:00
void /* PRIVATE */
2001-06-23 13:03:17 +00:00
png_write_oFFs(png_structp png_ptr, png_int_32 x_offset, png_int_32 y_offset,
1995-07-20 07:43:20 +00:00
int unit_type)
{
1999-11-29 05:32:18 +00:00
#ifdef PNG_USE_LOCAL_ARRAYS
2007-09-27 00:34:29 +00:00
PNG_oFFs;
1999-11-29 05:32:18 +00:00
#endif
1995-07-20 07:43:20 +00:00
png_byte buf[9];
2008-12-01 14:58:57 +00:00
png_debug(1, "in png_write_oFFs");
1997-05-16 07:46:07 +00:00
if (unit_type >= PNG_OFFSET_LAST)
png_warning(png_ptr, "Unrecognized unit type for oFFs chunk");
1996-06-05 20:50:50 +00:00
2001-06-23 13:03:17 +00:00
png_save_int_32(buf, x_offset);
png_save_int_32(buf + 4, y_offset);
1996-01-26 07:38:47 +00:00
buf[8] = (png_byte)unit_type;
1995-07-20 07:43:20 +00:00
2008-07-10 14:10:58 +00:00
png_write_chunk(png_ptr, (png_bytep)png_oFFs, buf, (png_size_t)9);
1995-07-20 07:43:20 +00:00
}
1995-09-26 10:22:39 +00:00
#endif
#ifdef PNG_WRITE_pCAL_SUPPORTED
2009-05-20 17:43:52 +00:00
/* Write the pCAL chunk (described in the PNG extensions document) */
2000-05-06 19:09:57 +00:00
void /* PRIVATE */
1997-05-16 07:46:07 +00:00
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)
{
1999-11-29 05:32:18 +00:00
#ifdef PNG_USE_LOCAL_ARRAYS
2007-09-27 00:34:29 +00:00
PNG_pCAL;
1999-11-29 05:32:18 +00:00
#endif
1998-12-29 17:47:59 +00:00
png_size_t purpose_len, units_len, total_len;
1997-05-16 07:46:07 +00:00
png_uint_32p params_len;
png_byte buf[10];
1998-01-01 13:13:13 +00:00
png_charp new_purpose;
1997-05-16 07:46:07 +00:00
int i;
2008-12-01 14:58:57 +00:00
png_debug1(1, "in png_write_pCAL (%d parameters)", nparams);
1997-05-16 07:46:07 +00:00
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;
2008-12-01 14:58:57 +00:00
png_debug1(3, "pCAL purpose length = %d", (int)purpose_len);
1997-05-16 07:46:07 +00:00
units_len = png_strlen(units) + (nparams == 0 ? 0 : 1);
2008-12-01 14:58:57 +00:00
png_debug1(3, "pCAL units length = %d", (int)units_len);
1997-05-16 07:46:07 +00:00
total_len = purpose_len + units_len + 10;
2008-07-10 14:10:58 +00:00
params_len = (png_uint_32p)png_malloc(png_ptr,
(png_uint_32)(nparams * png_sizeof(png_uint_32)));
1997-05-16 07:46:07 +00:00
/* 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);
2008-12-01 14:58:57 +00:00
png_debug2(3, "pCAL parameter %d length = %lu", i,
2008-07-10 14:10:58 +00:00
(unsigned long) params_len[i]);
1997-05-16 07:46:07 +00:00
total_len += (png_size_t)params_len[i];
}
2008-12-01 14:58:57 +00:00
png_debug1(3, "pCAL total length = %d", (int)total_len);
2008-07-10 14:10:58 +00:00
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);
1997-05-16 07:46:07 +00:00
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]);
}
1998-01-17 04:06:18 +00:00
png_free(png_ptr, params_len);
1997-05-16 07:46:07 +00:00
png_write_chunk_end(png_ptr);
}
#endif
#ifdef PNG_WRITE_sCAL_SUPPORTED
2009-05-20 17:43:52 +00:00
/* Write the sCAL chunk */
#if defined(PNG_FLOATING_POINT_SUPPORTED) && defined(PNG_STDIO_SUPPORTED)
2000-05-06 19:09:57 +00:00
void /* PRIVATE */
png_write_sCAL(png_structp png_ptr, int unit, double width, double height)
1999-12-10 15:43:02 +00:00
{
#ifdef PNG_USE_LOCAL_ARRAYS
2007-09-27 00:34:29 +00:00
PNG_sCAL;
1999-12-10 15:43:02 +00:00
#endif
char buf[64];
1999-12-10 15:43:02 +00:00
png_size_t total_len;
2008-12-01 14:58:57 +00:00
png_debug(1, "in png_write_sCAL");
1999-12-10 15:43:02 +00:00
buf[0] = (char)unit;
#ifdef _WIN32_WCE
2000-07-08 18:19:41 +00:00
/* sprintf() function is not supported on WindowsCE */
{
wchar_t wc_buf[32];
size_t wc_len;
2000-07-08 18:19:41 +00:00
swprintf(wc_buf, TEXT("%12.12e"), width);
wc_len = wcslen(wc_buf);
WideCharToMultiByte(CP_ACP, 0, wc_buf, -1, buf + 1, wc_len, NULL, NULL);
total_len = wc_len + 2;
2000-07-08 18:19:41 +00:00
swprintf(wc_buf, TEXT("%12.12e"), height);
wc_len = wcslen(wc_buf);
WideCharToMultiByte(CP_ACP, 0, wc_buf, -1, buf + total_len, wc_len,
NULL, NULL);
total_len += wc_len;
2000-07-08 18:19:41 +00:00
}
#else
2007-05-21 02:40:52 +00:00
png_snprintf(buf + 1, 63, "%12.12e", width);
total_len = 1 + png_strlen(buf + 1) + 1;
2007-05-21 02:40:52 +00:00
png_snprintf(buf + total_len, 64-total_len, "%12.12e", height);
total_len += png_strlen(buf + total_len);
2000-07-08 18:19:41 +00:00
#endif
1999-12-10 15:43:02 +00:00
2008-12-01 14:58:57 +00:00
png_debug1(3, "sCAL total length = %u", (unsigned int)total_len);
2008-07-10 14:10:58 +00:00
png_write_chunk(png_ptr, (png_bytep)png_sCAL, (png_bytep)buf, total_len);
1999-12-10 15:43:02 +00:00
}
2000-02-05 05:40:16 +00:00
#else
#ifdef PNG_FIXED_POINT_SUPPORTED
2000-05-06 19:09:57 +00:00
void /* PRIVATE */
2000-02-05 05:40:16 +00:00
png_write_sCAL_s(png_structp png_ptr, int unit, png_charp width,
1999-12-10 15:43:02 +00:00
png_charp height)
{
#ifdef PNG_USE_LOCAL_ARRAYS
2007-09-27 00:34:29 +00:00
PNG_sCAL;
1999-12-10 15:43:02 +00:00
#endif
png_byte buf[64];
png_size_t wlen, hlen, total_len;
1999-12-10 15:43:02 +00:00
2008-12-01 14:58:57 +00:00
png_debug(1, "in png_write_sCAL_s");
1999-12-10 15:43:02 +00:00
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;
}
1999-12-10 15:43:02 +00:00
buf[0] = (png_byte)unit;
2009-05-20 17:43:52 +00:00
png_memcpy(buf + 1, width, wlen + 1); /* Append the '\0' here */
png_memcpy(buf + wlen + 2, height, hlen); /* Do NOT append the '\0' here */
1999-12-10 15:43:02 +00:00
2008-12-01 14:58:57 +00:00
png_debug1(3, "sCAL total length = %u", (unsigned int)total_len);
2008-07-10 14:10:58 +00:00
png_write_chunk(png_ptr, (png_bytep)png_sCAL, buf, total_len);
1999-12-10 15:43:02 +00:00
}
#endif
2000-02-05 05:40:16 +00:00
#endif
#endif
1999-12-10 15:43:02 +00:00
#ifdef PNG_WRITE_pHYs_SUPPORTED
2009-05-20 17:43:52 +00:00
/* Write the pHYs chunk */
2000-05-06 19:09:57 +00:00
void /* PRIVATE */
1997-05-16 07:46:07 +00:00
png_write_pHYs(png_structp png_ptr, png_uint_32 x_pixels_per_unit,
png_uint_32 y_pixels_per_unit,
1995-07-20 07:43:20 +00:00
int unit_type)
{
1999-11-29 05:32:18 +00:00
#ifdef PNG_USE_LOCAL_ARRAYS
2007-09-27 00:34:29 +00:00
PNG_pHYs;
1999-11-29 05:32:18 +00:00
#endif
1995-07-20 07:43:20 +00:00
png_byte buf[9];
2008-12-01 14:58:57 +00:00
png_debug(1, "in png_write_pHYs");
1997-05-16 07:46:07 +00:00
if (unit_type >= PNG_RESOLUTION_LAST)
png_warning(png_ptr, "Unrecognized unit type for pHYs chunk");
1996-06-05 20:50:50 +00:00
1997-05-16 07:46:07 +00:00
png_save_uint_32(buf, x_pixels_per_unit);
png_save_uint_32(buf + 4, y_pixels_per_unit);
1996-01-26 07:38:47 +00:00
buf[8] = (png_byte)unit_type;
1995-07-20 07:43:20 +00:00
2008-07-10 14:10:58 +00:00
png_write_chunk(png_ptr, (png_bytep)png_pHYs, buf, (png_size_t)9);
1995-07-20 07:43:20 +00:00
}
1995-09-26 10:22:39 +00:00
#endif
1995-07-20 07:43:20 +00:00
#ifdef PNG_WRITE_tIME_SUPPORTED
1998-01-01 13:13:13 +00:00
/* Write the tIME chunk. Use either png_convert_from_struct_tm()
* or png_convert_from_time_t(), or fill in the structure yourself.
*/
2000-05-06 19:09:57 +00:00
void /* PRIVATE */
1995-12-19 09:22:19 +00:00
png_write_tIME(png_structp png_ptr, png_timep mod_time)
1995-07-20 07:43:20 +00:00
{
1999-11-29 05:32:18 +00:00
#ifdef PNG_USE_LOCAL_ARRAYS
2007-09-27 00:34:29 +00:00
PNG_tIME;
1999-11-29 05:32:18 +00:00
#endif
1995-07-20 07:43:20 +00:00
png_byte buf[7];
2008-12-01 14:58:57 +00:00
png_debug(1, "in png_write_tIME");
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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;
}
1995-07-20 07:43:20 +00:00
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;
2008-07-10 14:10:58 +00:00
png_write_chunk(png_ptr, (png_bytep)png_tIME, buf, (png_size_t)7);
1995-07-20 07:43:20 +00:00
}
1995-09-26 10:22:39 +00:00
#endif
1995-07-20 07:43:20 +00:00
2009-05-20 17:43:52 +00:00
/* Initializes the row writing capability of libpng */
2000-05-06 19:09:57 +00:00
void /* PRIVATE */
1995-12-19 09:22:19 +00:00
png_write_start_row(png_structp png_ptr)
1995-07-20 07:43:20 +00:00
{
2007-08-30 03:31:46 +00:00
#ifdef PNG_WRITE_INTERLACING_SUPPORTED
2009-05-20 17:43:52 +00:00
/* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
1999-12-10 15:43:02 +00:00
2009-05-20 17:43:52 +00:00
/* Start of interlace block */
1999-11-27 16:22:33 +00:00
int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
1999-12-10 15:43:02 +00:00
2009-05-20 17:43:52 +00:00
/* Offset to next interlace block */
1999-11-27 16:22:33 +00:00
int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
1999-12-10 15:43:02 +00:00
2009-05-20 17:43:52 +00:00
/* Start of interlace block in the y direction */
1999-11-27 16:22:33 +00:00
int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
1999-12-10 15:43:02 +00:00
2009-05-20 17:43:52 +00:00
/* Offset to next interlace block in the y direction */
1999-11-27 16:22:33 +00:00
int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
1999-11-29 05:32:18 +00:00
#endif
1999-12-10 15:43:02 +00:00
1997-05-16 07:46:07 +00:00
png_size_t buf_size;
2008-12-01 14:58:57 +00:00
png_debug(1, "in png_write_start_row");
2004-08-04 11:34:52 +00:00
buf_size = (png_size_t)(PNG_ROWBYTES(
2008-07-10 14:10:58 +00:00
png_ptr->usr_channels*png_ptr->usr_bit_depth, png_ptr->width) + 1);
1997-05-16 07:46:07 +00:00
2009-05-20 17:43:52 +00:00
/* Set up row buffer */
2008-07-10 14:10:58 +00:00
png_ptr->row_buf = (png_bytep)png_malloc(png_ptr,
(png_uint_32)buf_size);
1997-05-16 07:46:07 +00:00
png_ptr->row_buf[0] = PNG_FILTER_VALUE_NONE;
1996-06-05 20:50:50 +00:00
#ifdef PNG_WRITE_FILTER_SUPPORTED
2009-05-20 17:43:52 +00:00
/* Set up filtering buffer, if using this filter */
1996-06-05 20:50:50 +00:00
if (png_ptr->do_filter & PNG_FILTER_SUB)
1995-07-20 07:43:20 +00:00
{
1997-05-16 07:46:07 +00:00
png_ptr->sub_row = (png_bytep)png_malloc(png_ptr,
2008-07-10 14:10:58 +00:00
(png_uint_32)(png_ptr->rowbytes + 1));
1997-05-16 07:46:07 +00:00
png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB;
1996-06-05 20:50:50 +00:00
}
1997-05-16 07:46:07 +00:00
/* We only need to keep the previous row if we are using one of these. */
1996-06-05 20:50:50 +00:00
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_uint_32)buf_size);
1996-06-05 20:50:50 +00:00
if (png_ptr->do_filter & PNG_FILTER_UP)
{
2007-05-28 13:45:13 +00:00
png_ptr->up_row = (png_bytep)png_malloc(png_ptr,
(png_uint_32)(png_ptr->rowbytes + 1));
1997-05-16 07:46:07 +00:00
png_ptr->up_row[0] = PNG_FILTER_VALUE_UP;
1996-06-05 20:50:50 +00:00
}
if (png_ptr->do_filter & PNG_FILTER_AVG)
{
1998-02-07 16:20:57 +00:00
png_ptr->avg_row = (png_bytep)png_malloc(png_ptr,
(png_uint_32)(png_ptr->rowbytes + 1));
1997-05-16 07:46:07 +00:00
png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG;
1996-06-05 20:50:50 +00:00
}
if (png_ptr->do_filter & PNG_FILTER_PAETH)
{
2007-05-28 13:45:13 +00:00
png_ptr->paeth_row = (png_bytep)png_malloc(png_ptr,
(png_uint_32)(png_ptr->rowbytes + 1));
1997-05-16 07:46:07 +00:00
png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH;
1996-06-05 20:50:50 +00:00
}
1995-07-20 07:43:20 +00:00
}
#endif /* PNG_WRITE_FILTER_SUPPORTED */
1995-07-20 07:43:20 +00:00
1998-01-31 03:45:12 +00:00
#ifdef PNG_WRITE_INTERLACING_SUPPORTED
2009-05-20 17:43:52 +00:00
/* If interlaced, we need to set up width and height of pass */
1996-01-26 07:38:47 +00:00
if (png_ptr->interlaced)
1995-07-20 07:43:20 +00:00
{
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];
1997-05-16 07:46:07 +00:00
png_ptr->usr_width = (png_ptr->width + png_pass_inc[0] - 1 -
png_pass_start[0]) / png_pass_inc[0];
1995-07-20 07:43:20 +00:00
}
else
{
png_ptr->num_rows = png_ptr->height;
png_ptr->usr_width = png_ptr->width;
}
}
else
1998-01-31 03:45:12 +00:00
#endif
1996-01-26 07:38:47 +00:00
{
1995-07-20 07:43:20 +00:00
png_ptr->num_rows = png_ptr->height;
png_ptr->usr_width = png_ptr->width;
}
1997-01-17 07:34:35 +00:00
png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
png_ptr->zstream.next_out = png_ptr->zbuf;
1995-07-20 07:43:20 +00:00
}
1997-05-16 07:46:07 +00:00
/* Internal use only. Called when finished processing a row of data. */
2000-05-06 19:09:57 +00:00
void /* PRIVATE */
1995-12-19 09:22:19 +00:00
png_write_finish_row(png_structp png_ptr)
1995-07-20 07:43:20 +00:00
{
2007-08-30 03:31:46 +00:00
#ifdef PNG_WRITE_INTERLACING_SUPPORTED
2009-05-20 17:43:52 +00:00
/* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
1999-12-10 15:43:02 +00:00
2009-05-20 17:43:52 +00:00
/* Start of interlace block */
1999-11-27 16:22:33 +00:00
int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
1999-12-10 15:43:02 +00:00
2009-05-20 17:43:52 +00:00
/* Offset to next interlace block */
1999-11-27 16:22:33 +00:00
int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
1999-12-10 15:43:02 +00:00
2009-05-20 17:43:52 +00:00
/* Start of interlace block in the y direction */
1999-11-27 16:22:33 +00:00
int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
1999-12-10 15:43:02 +00:00
2009-05-20 17:43:52 +00:00
/* Offset to next interlace block in the y direction */
1999-11-27 16:22:33 +00:00
int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
1999-11-29 05:32:18 +00:00
#endif
1999-12-10 15:43:02 +00:00
1995-07-20 07:43:20 +00:00
int ret;
2008-12-01 14:58:57 +00:00
png_debug(1, "in png_write_finish_row");
2009-05-20 17:43:52 +00:00
/* Next row */
1995-07-20 07:43:20 +00:00
png_ptr->row_number++;
1996-06-17 21:24:45 +00:00
2009-05-20 17:43:52 +00:00
/* See if we are done */
1995-12-19 09:22:19 +00:00
if (png_ptr->row_number < png_ptr->num_rows)
1996-01-26 07:38:47 +00:00
return;
1995-07-20 07:43:20 +00:00
1998-01-31 03:45:12 +00:00
#ifdef PNG_WRITE_INTERLACING_SUPPORTED
2009-05-20 17:43:52 +00:00
/* If interlaced, go to next pass */
1995-07-20 07:43:20 +00:00
if (png_ptr->interlaced)
{
png_ptr->row_number = 0;
if (png_ptr->transformations & PNG_INTERLACE)
{
png_ptr->pass++;
}
else
{
2009-05-20 17:43:52 +00:00
/* Loop until we find a non-zero width or height pass */
1995-07-20 07:43:20 +00:00
do
{
png_ptr->pass++;
if (png_ptr->pass >= 7)
break;
1996-01-26 07:38:47 +00:00
png_ptr->usr_width = (png_ptr->width +
1995-07-20 07:43:20 +00:00
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];
1995-09-26 10:22:39 +00:00
if (png_ptr->transformations & PNG_INTERLACE)
break;
1995-07-20 07:43:20 +00:00
} while (png_ptr->usr_width == 0 || png_ptr->num_rows == 0);
}
2009-05-20 17:43:52 +00:00
/* Reset the row above the image for the next pass */
1996-01-26 07:38:47 +00:00
if (png_ptr->pass < 7)
1996-06-17 21:24:45 +00:00
{
1997-05-16 07:46:07 +00:00
if (png_ptr->prev_row != NULL)
1998-12-29 17:47:59 +00:00
png_memset(png_ptr->prev_row, 0,
2004-08-04 11:34:52 +00:00
(png_size_t)(PNG_ROWBYTES(png_ptr->usr_channels*
2008-07-10 14:10:58 +00:00
png_ptr->usr_bit_depth, png_ptr->width)) + 1);
1995-07-20 07:43:20 +00:00
return;
1996-06-17 21:24:45 +00:00
}
1995-07-20 07:43:20 +00:00
}
1998-01-31 03:45:12 +00:00
#endif
1995-07-20 07:43:20 +00:00
2009-05-20 17:43:52 +00:00
/* If we get here, we've just written the last row, so we need
1995-07-20 07:43:20 +00:00
to flush the compressor */
do
{
2009-05-20 17:43:52 +00:00
/* Tell the compressor we are done */
1997-01-17 07:34:35 +00:00
ret = deflate(&png_ptr->zstream, Z_FINISH);
2009-05-20 17:43:52 +00:00
/* Check for an error */
2000-05-29 13:58:03 +00:00
if (ret == Z_OK)
{
2009-05-20 17:43:52 +00:00
/* Check to see if we need more room */
2000-05-29 13:58:03 +00:00
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)
1995-07-20 07:43:20 +00:00
{
1997-05-16 07:46:07 +00:00
if (png_ptr->zstream.msg != NULL)
1997-01-17 07:34:35 +00:00
png_error(png_ptr, png_ptr->zstream.msg);
1995-07-20 07:43:20 +00:00
else
1995-12-19 09:22:19 +00:00
png_error(png_ptr, "zlib error");
1995-07-20 07:43:20 +00:00
}
} while (ret != Z_STREAM_END);
2009-05-20 17:43:52 +00:00
/* Write any extra space */
1997-01-17 07:34:35 +00:00
if (png_ptr->zstream.avail_out < png_ptr->zbuf_size)
1995-07-20 07:43:20 +00:00
{
png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size -
1997-01-17 07:34:35 +00:00
png_ptr->zstream.avail_out);
1995-07-20 07:43:20 +00:00
}
1997-01-17 07:34:35 +00:00
deflateReset(&png_ptr->zstream);
2004-11-13 04:04:56 +00:00
png_ptr->zstream.data_type = Z_BINARY;
1995-07-20 07:43:20 +00:00
}
#ifdef PNG_WRITE_INTERLACING_SUPPORTED
1998-01-01 13:13:13 +00:00
/* 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.
*/
2000-05-06 19:09:57 +00:00
void /* PRIVATE */
1995-12-19 09:22:19 +00:00
png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass)
1995-07-20 07:43:20 +00:00
{
2009-05-20 17:43:52 +00:00
/* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
1999-12-10 15:43:02 +00:00
2009-05-20 17:43:52 +00:00
/* Start of interlace block */
1999-11-27 16:22:33 +00:00
int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
1999-12-10 15:43:02 +00:00
2009-05-20 17:43:52 +00:00
/* Offset to next interlace block */
1999-11-27 16:22:33 +00:00
int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
1999-12-10 15:43:02 +00:00
2008-12-01 14:58:57 +00:00
png_debug(1, "in png_do_write_interlace");
2009-05-20 17:43:52 +00:00
/* We don't have to do anything on the last pass (6) */
#ifdef PNG_USELESS_TESTS_SUPPORTED
1997-05-16 07:46:07 +00:00
if (row != NULL && row_info != NULL && pass < 6)
#else
if (pass < 6)
#endif
1995-07-20 07:43:20 +00:00
{
2009-05-20 17:43:52 +00:00
/* Each pixel depth is handled separately */
1995-07-20 07:43:20 +00:00
switch (row_info->pixel_depth)
1996-01-26 07:38:47 +00:00
{
1995-07-20 07:43:20 +00:00
case 1:
{
1995-12-19 09:22:19 +00:00
png_bytep sp;
png_bytep dp;
1995-07-20 07:43:20 +00:00
int shift;
int d;
int value;
1998-05-02 17:52:25 +00:00
png_uint_32 i;
png_uint_32 row_width = row_info->width;
1995-07-20 07:43:20 +00:00
dp = row;
d = 0;
shift = 7;
1998-05-02 17:52:25 +00:00
for (i = png_pass_start[pass]; i < row_width;
1995-07-20 07:43:20 +00:00
i += png_pass_inc[pass])
{
sp = row + (png_size_t)(i >> 3);
2000-02-05 05:40:16 +00:00
value = (int)(*sp >> (7 - (int)(i & 0x07))) & 0x01;
1995-07-20 07:43:20 +00:00
d |= (value << shift);
if (shift == 0)
{
shift = 7;
1996-01-26 07:38:47 +00:00
*dp++ = (png_byte)d;
1995-07-20 07:43:20 +00:00
d = 0;
}
else
shift--;
}
if (shift != 7)
1996-01-26 07:38:47 +00:00
*dp = (png_byte)d;
1995-07-20 07:43:20 +00:00
break;
}
case 2:
1996-01-26 07:38:47 +00:00
{
1995-12-19 09:22:19 +00:00
png_bytep sp;
png_bytep dp;
1995-07-20 07:43:20 +00:00
int shift;
int d;
int value;
1998-05-02 17:52:25 +00:00
png_uint_32 i;
png_uint_32 row_width = row_info->width;
1995-07-20 07:43:20 +00:00
dp = row;
shift = 6;
d = 0;
1998-05-02 17:52:25 +00:00
for (i = png_pass_start[pass]; i < row_width;
1995-07-20 07:43:20 +00:00
i += png_pass_inc[pass])
{
sp = row + (png_size_t)(i >> 2);
2000-02-05 05:40:16 +00:00
value = (*sp >> ((3 - (int)(i & 0x03)) << 1)) & 0x03;
1995-07-20 07:43:20 +00:00
d |= (value << shift);
if (shift == 0)
{
shift = 6;
1996-01-26 07:38:47 +00:00
*dp++ = (png_byte)d;
1995-07-20 07:43:20 +00:00
d = 0;
}
else
shift -= 2;
}
if (shift != 6)
1996-01-26 07:38:47 +00:00
*dp = (png_byte)d;
1995-07-20 07:43:20 +00:00
break;
}
case 4:
{
1995-12-19 09:22:19 +00:00
png_bytep sp;
png_bytep dp;
1996-01-26 07:38:47 +00:00
int shift;
1995-07-20 07:43:20 +00:00
int d;
int value;
1998-05-02 17:52:25 +00:00
png_uint_32 i;
png_uint_32 row_width = row_info->width;
1995-07-20 07:43:20 +00:00
dp = row;
shift = 4;
d = 0;
1998-05-02 17:52:25 +00:00
for (i = png_pass_start[pass]; i < row_width;
1995-07-20 07:43:20 +00:00
i += png_pass_inc[pass])
{
sp = row + (png_size_t)(i >> 1);
2000-02-05 05:40:16 +00:00
value = (*sp >> ((1 - (int)(i & 0x01)) << 2)) & 0x0f;
1995-07-20 07:43:20 +00:00
d |= (value << shift);
if (shift == 0)
{
1996-01-26 07:38:47 +00:00
shift = 4;
*dp++ = (png_byte)d;
1995-07-20 07:43:20 +00:00
d = 0;
}
else
shift -= 4;
}
if (shift != 4)
1996-01-26 07:38:47 +00:00
*dp = (png_byte)d;
1995-07-20 07:43:20 +00:00
break;
}
default:
{
1995-12-19 09:22:19 +00:00
png_bytep sp;
png_bytep dp;
1998-05-02 17:52:25 +00:00
png_uint_32 i;
png_uint_32 row_width = row_info->width;
1997-05-16 07:46:07 +00:00
png_size_t pixel_bytes;
1995-07-20 07:43:20 +00:00
2009-05-20 17:43:52 +00:00
/* Start at the beginning */
1995-07-20 07:43:20 +00:00
dp = row;
2009-05-20 17:43:52 +00:00
/* Find out how many bytes each pixel takes up */
1995-07-20 07:43:20 +00:00
pixel_bytes = (row_info->pixel_depth >> 3);
2009-05-20 17:43:52 +00:00
/* Loop through the row, only looking at the pixels that
1995-07-20 07:43:20 +00:00
matter */
1998-05-02 17:52:25 +00:00
for (i = png_pass_start[pass]; i < row_width;
1995-07-20 07:43:20 +00:00
i += png_pass_inc[pass])
{
2009-05-20 17:43:52 +00:00
/* Find out where the original pixel is */
1998-02-09 02:56:40 +00:00
sp = row + (png_size_t)i * pixel_bytes;
2009-05-20 17:43:52 +00:00
/* Move the pixel */
1995-07-20 07:43:20 +00:00
if (dp != sp)
1995-09-26 10:22:39 +00:00
png_memcpy(dp, sp, pixel_bytes);
2009-05-20 17:43:52 +00:00
/* Next pixel */
1995-07-20 07:43:20 +00:00
dp += pixel_bytes;
}
1996-01-26 07:38:47 +00:00
break;
1995-07-20 07:43:20 +00:00
}
}
2009-05-20 17:43:52 +00:00
/* Set new row width */
1995-07-20 07:43:20 +00:00
row_info->width = (row_info->width +
png_pass_inc[pass] - 1 -
png_pass_start[pass]) /
png_pass_inc[pass];
2004-08-04 11:34:52 +00:00
row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,
row_info->width);
1995-07-20 07:43:20 +00:00
}
}
1995-09-26 10:22:39 +00:00
#endif
1995-07-20 07:43:20 +00:00
1997-05-16 07:46:07 +00:00
/* 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
1998-01-01 13:13:13 +00:00
* chosen filter.
*/
2004-11-03 03:49:39 +00:00
#define PNG_MAXSUM (((png_uint_32)(-1)) >> 1)
1997-05-16 07:46:07 +00:00
#define PNG_HISHIFT 10
1998-03-07 20:33:00 +00:00
#define PNG_LOMASK ((png_uint_32)0xffffL)
#define PNG_HIMASK ((png_uint_32)(~PNG_LOMASK >> PNG_HISHIFT))
2000-05-06 19:09:57 +00:00
void /* PRIVATE */
1996-06-05 20:50:50 +00:00
png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
1995-07-20 07:43:20 +00:00
{
2007-08-30 03:31:46 +00:00
png_bytep best_row;
#ifdef PNG_WRITE_FILTER_SUPPORTED
2007-08-30 03:31:46 +00:00
png_bytep prev_row, row_buf;
1997-05-16 07:46:07 +00:00
png_uint_32 mins, bpp;
1998-04-21 20:03:57 +00:00
png_byte filter_to_do = png_ptr->do_filter;
1998-05-02 17:52:25 +00:00
png_uint_32 row_bytes = row_info->rowbytes;
#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
1998-05-02 17:52:25 +00:00
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
2009-05-20 17:43:52 +00:00
/* Find out how many bytes offset each pixel is */
2004-08-04 11:34:52 +00:00
bpp = (row_info->pixel_depth + 7) >> 3;
1996-06-05 20:50:50 +00:00
prev_row = png_ptr->prev_row;
2007-08-30 03:31:46 +00:00
#endif
best_row = png_ptr->row_buf;
#ifdef PNG_WRITE_FILTER_SUPPORTED
2007-08-30 03:31:46 +00:00
row_buf = best_row;
1997-05-16 07:46:07 +00:00
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
1998-05-21 14:27:50 +00:00
* from zero, using anything >= 128 as negative numbers. This is known
1997-05-16 07:46:07 +00:00
* as the "minimum sum of absolute differences" heuristic. Other
1998-04-21 20:03:57 +00:00
* heuristics are the "weighted minimum sum of absolute differences"
1997-05-16 07:46:07 +00:00
* (experimental and can in theory improve compression), and the "zlib
1998-06-06 20:31:35 +00:00
* 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
1997-05-16 07:46:07 +00:00
* computationally expensive).
1998-06-06 20:31:35 +00:00
*
* 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)
1997-05-16 07:46:07 +00:00
*/
1995-09-26 10:22:39 +00:00
1998-04-21 20:03:57 +00:00
1996-06-05 20:50:50 +00:00
/* We don't need to test the 'no filter' case if this is the only filter
1997-05-16 07:46:07 +00:00
* that has been chosen, as it doesn't actually do anything to the data.
*/
2000-02-05 05:40:16 +00:00
if ((filter_to_do & PNG_FILTER_NONE) &&
1998-04-21 20:03:57 +00:00
filter_to_do != PNG_FILTER_NONE)
1995-07-20 07:43:20 +00:00
{
1996-06-05 20:50:50 +00:00
png_bytep rp;
png_uint_32 sum = 0;
1998-05-02 17:52:25 +00:00
png_uint_32 i;
1997-05-16 07:46:07 +00:00
int v;
1995-07-20 07:43:20 +00:00
1998-05-02 17:52:25 +00:00
for (i = 0, rp = row_buf + 1; i < row_bytes; i++, rp++)
1996-06-05 20:50:50 +00:00
{
v = *rp;
sum += (v < 128) ? v : 256 - v;
}
1997-05-16 07:46:07 +00:00
#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
1997-05-16 07:46:07 +00:00
if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
{
png_uint_32 sumhi, sumlo;
1998-05-09 15:02:29 +00:00
int j;
1997-05-16 07:46:07 +00:00
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 */
1998-05-02 17:52:25 +00:00
for (j = 0; j < num_p_filters; j++)
1997-05-16 07:46:07 +00:00
{
1998-05-02 17:52:25 +00:00
if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE)
1997-05-16 07:46:07 +00:00
{
1998-05-02 17:52:25 +00:00
sumlo = (sumlo * png_ptr->filter_weights[j]) >>
1997-05-16 07:46:07 +00:00
PNG_WEIGHT_SHIFT;
1998-05-02 17:52:25 +00:00
sumhi = (sumhi * png_ptr->filter_weights[j]) >>
1997-05-16 07:46:07 +00:00
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
1996-06-05 20:50:50 +00:00
mins = sum;
}
1995-07-20 07:43:20 +00:00
2009-05-20 17:43:52 +00:00
/* Sub filter */
1998-04-21 20:03:57 +00:00
if (filter_to_do == PNG_FILTER_SUB)
2009-05-20 17:43:52 +00:00
/* It's the only filter so no testing is needed */
1998-04-21 20:03:57 +00:00
{
png_bytep rp, lp, dp;
1998-05-02 17:52:25 +00:00
png_uint_32 i;
1998-04-21 20:03:57 +00:00
for (i = 0, rp = row_buf + 1, dp = png_ptr->sub_row + 1; i < bpp;
i++, rp++, dp++)
{
*dp = *rp;
}
1998-05-02 17:52:25 +00:00
for (lp = row_buf + 1; i < row_bytes;
1998-04-21 20:03:57 +00:00
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)
1996-06-05 20:50:50 +00:00
{
png_bytep rp, dp, lp;
1997-05-16 07:46:07 +00:00
png_uint_32 sum = 0, lmins = mins;
1998-05-02 17:52:25 +00:00
png_uint_32 i;
1997-05-16 07:46:07 +00:00
int v;
#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
1998-04-21 20:03:57 +00:00
/* We temporarily increase the "minimum sum" by the factor we
1997-05-16 07:46:07 +00:00
* 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)
{
1998-05-09 15:02:29 +00:00
int j;
1997-05-16 07:46:07 +00:00
png_uint_32 lmhi, lmlo;
lmlo = lmins & PNG_LOMASK;
lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
1998-05-02 17:52:25 +00:00
for (j = 0; j < num_p_filters; j++)
1997-05-16 07:46:07 +00:00
{
1998-05-02 17:52:25 +00:00
if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB)
1997-05-16 07:46:07 +00:00
{
1998-05-02 17:52:25 +00:00
lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
1997-05-16 07:46:07 +00:00
PNG_WEIGHT_SHIFT;
1998-05-02 17:52:25 +00:00
lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
1997-05-16 07:46:07 +00:00
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
1995-09-26 10:22:39 +00:00
1996-06-05 20:50:50 +00:00
for (i = 0, rp = row_buf + 1, dp = png_ptr->sub_row + 1; i < bpp;
i++, rp++, dp++)
{
v = *dp = *rp;
1995-07-20 07:43:20 +00:00
1996-06-05 20:50:50 +00:00
sum += (v < 128) ? v : 256 - v;
}
2004-07-18 03:45:44 +00:00
for (lp = row_buf + 1; i < row_bytes;
1998-02-07 16:20:57 +00:00
i++, rp++, lp++, dp++)
1996-06-05 20:50:50 +00:00
{
v = *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff);
sum += (v < 128) ? v : 256 - v;
1997-05-16 07:46:07 +00:00
if (sum > lmins) /* We are already worse, don't continue. */
break;
}
#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
1997-05-16 07:46:07 +00:00
if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
{
1998-05-09 15:02:29 +00:00
int j;
1997-05-16 07:46:07 +00:00
png_uint_32 sumhi, sumlo;
sumlo = sum & PNG_LOMASK;
sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
1998-05-02 17:52:25 +00:00
for (j = 0; j < num_p_filters; j++)
1997-05-16 07:46:07 +00:00
{
1998-05-02 17:52:25 +00:00
if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB)
1997-05-16 07:46:07 +00:00
{
1998-05-02 17:52:25 +00:00
sumlo = (sumlo * png_ptr->inv_filter_weights[j]) >>
1997-05-16 07:46:07 +00:00
PNG_WEIGHT_SHIFT;
1998-05-02 17:52:25 +00:00
sumhi = (sumhi * png_ptr->inv_filter_weights[j]) >>
1997-05-16 07:46:07 +00:00
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;
1996-06-05 20:50:50 +00:00
}
1997-05-16 07:46:07 +00:00
#endif
1996-06-05 20:50:50 +00:00
if (sum < mins)
{
mins = sum;
best_row = png_ptr->sub_row;
}
1995-07-20 07:43:20 +00:00
}
2009-05-20 17:43:52 +00:00
/* Up filter */
1998-04-21 20:03:57 +00:00
if (filter_to_do == PNG_FILTER_UP)
{
png_bytep rp, dp, pp;
1998-05-02 17:52:25 +00:00
png_uint_32 i;
1998-04-21 20:03:57 +00:00
for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1,
1998-05-02 17:52:25 +00:00
pp = prev_row + 1; i < row_bytes;
1998-04-21 20:03:57 +00:00
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)
1996-06-05 20:50:50 +00:00
{
png_bytep rp, dp, pp;
1997-05-16 07:46:07 +00:00
png_uint_32 sum = 0, lmins = mins;
1998-05-02 17:52:25 +00:00
png_uint_32 i;
1997-05-16 07:46:07 +00:00
int v;
1998-04-21 20:03:57 +00:00
#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
1997-05-16 07:46:07 +00:00
if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
{
1998-05-09 15:02:29 +00:00
int j;
1997-05-16 07:46:07 +00:00
png_uint_32 lmhi, lmlo;
lmlo = lmins & PNG_LOMASK;
lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
1998-05-02 17:52:25 +00:00
for (j = 0; j < num_p_filters; j++)
1997-05-16 07:46:07 +00:00
{
1998-05-02 17:52:25 +00:00
if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP)
1997-05-16 07:46:07 +00:00
{
1998-05-02 17:52:25 +00:00
lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
1997-05-16 07:46:07 +00:00
PNG_WEIGHT_SHIFT;
1998-05-02 17:52:25 +00:00
lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
1997-05-16 07:46:07 +00:00
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
1995-07-20 07:43:20 +00:00
1996-06-05 20:50:50 +00:00
for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1,
1998-05-02 17:52:25 +00:00
pp = prev_row + 1; i < row_bytes; i++)
1996-06-05 20:50:50 +00:00
{
1998-05-02 17:52:25 +00:00
v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
1996-06-05 20:50:50 +00:00
sum += (v < 128) ? v : 256 - v;
1997-05-16 07:46:07 +00:00
if (sum > lmins) /* We are already worse, don't continue. */
break;
1996-06-05 20:50:50 +00:00
}
1997-05-16 07:46:07 +00:00
#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
1997-05-16 07:46:07 +00:00
if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
{
1998-05-09 15:02:29 +00:00
int j;
1997-05-16 07:46:07 +00:00
png_uint_32 sumhi, sumlo;
sumlo = sum & PNG_LOMASK;
sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
1998-05-02 17:52:25 +00:00
for (j = 0; j < num_p_filters; j++)
1997-05-16 07:46:07 +00:00
{
1998-05-02 17:52:25 +00:00
if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP)
1997-05-16 07:46:07 +00:00
{
1998-05-02 17:52:25 +00:00
sumlo = (sumlo * png_ptr->filter_weights[j]) >>
1997-05-16 07:46:07 +00:00
PNG_WEIGHT_SHIFT;
1998-05-02 17:52:25 +00:00
sumhi = (sumhi * png_ptr->filter_weights[j]) >>
1997-05-16 07:46:07 +00:00
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
1996-06-05 20:50:50 +00:00
if (sum < mins)
{
mins = sum;
best_row = png_ptr->up_row;
}
}
2009-05-20 17:43:52 +00:00
/* Avg filter */
1998-04-21 20:03:57 +00:00
if (filter_to_do == PNG_FILTER_AVG)
{
png_bytep rp, dp, pp, lp;
1998-05-02 17:52:25 +00:00
png_uint_32 i;
1998-04-21 20:03:57 +00:00
for (i = 0, rp = row_buf + 1, dp = png_ptr->avg_row + 1,
1998-05-02 17:52:25 +00:00
pp = prev_row + 1; i < bpp; i++)
1998-04-21 20:03:57 +00:00
{
1998-05-02 17:52:25 +00:00
*dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff);
1998-04-21 20:03:57 +00:00
}
1998-05-02 17:52:25 +00:00
for (lp = row_buf + 1; i < row_bytes; i++)
1998-04-21 20:03:57 +00:00
{
1998-05-02 17:52:25 +00:00
*dp++ = (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2))
& 0xff);
1998-04-21 20:03:57 +00:00
}
best_row = png_ptr->avg_row;
}
else if (filter_to_do & PNG_FILTER_AVG)
1995-07-20 07:43:20 +00:00
{
1996-06-05 20:50:50 +00:00
png_bytep rp, dp, pp, lp;
1997-05-16 07:46:07 +00:00
png_uint_32 sum = 0, lmins = mins;
1998-05-02 17:52:25 +00:00
png_uint_32 i;
1997-05-16 07:46:07 +00:00
int v;
#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
1997-05-16 07:46:07 +00:00
if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
{
1998-05-09 15:02:29 +00:00
int j;
1997-05-16 07:46:07 +00:00
png_uint_32 lmhi, lmlo;
lmlo = lmins & PNG_LOMASK;
lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
1998-05-02 17:52:25 +00:00
for (j = 0; j < num_p_filters; j++)
1997-05-16 07:46:07 +00:00
{
1998-05-02 17:52:25 +00:00
if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_AVG)
1997-05-16 07:46:07 +00:00
{
1998-05-02 17:52:25 +00:00
lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
1997-05-16 07:46:07 +00:00
PNG_WEIGHT_SHIFT;
1998-05-02 17:52:25 +00:00
lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
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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
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for (i = 0, rp = row_buf + 1, dp = png_ptr->avg_row + 1,
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pp = prev_row + 1; i < bpp; i++)
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{
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v = *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff);
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sum += (v < 128) ? v : 256 - v;
}
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for (lp = row_buf + 1; i < row_bytes; i++)
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{
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v = *dp++ =
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(png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2)) & 0xff);
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sum += (v < 128) ? v : 256 - v;
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if (sum > lmins) /* We are already worse, don't continue. */
break;
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}
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#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
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if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
{
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int j;
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png_uint_32 sumhi, sumlo;
sumlo = sum & PNG_LOMASK;
sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
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for (j = 0; j < num_p_filters; j++)
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{
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if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE)
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{
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sumlo = (sumlo * png_ptr->filter_weights[j]) >>
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PNG_WEIGHT_SHIFT;
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sumhi = (sumhi * png_ptr->filter_weights[j]) >>
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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
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if (sum < mins)
{
mins = sum;
best_row = png_ptr->avg_row;
}
}
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/* Paeth filter */
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if (filter_to_do == PNG_FILTER_PAETH)
{
png_bytep rp, dp, pp, cp, lp;
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png_uint_32 i;
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for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1,
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pp = prev_row + 1; i < bpp; i++)
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{
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*dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
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}
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for (lp = row_buf + 1, cp = prev_row + 1; i < row_bytes; i++)
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{
int a, b, c, pa, pb, pc, p;
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b = *pp++;
c = *cp++;
a = *lp++;
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p = b - c;
pc = a - c;
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#ifdef PNG_USE_ABS
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pa = abs(p);
pb = abs(pc);
pc = abs(p + pc);
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#else
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pa = p < 0 ? -p : p;
pb = pc < 0 ? -pc : pc;
pc = (p + pc) < 0 ? -(p + pc) : p + pc;
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#endif
p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c;
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*dp++ = (png_byte)(((int)*rp++ - p) & 0xff);
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}
best_row = png_ptr->paeth_row;
}
else if (filter_to_do & PNG_FILTER_PAETH)
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{
png_bytep rp, dp, pp, cp, lp;
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png_uint_32 sum = 0, lmins = mins;
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png_uint_32 i;
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int v;
#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
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if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
{
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int j;
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png_uint_32 lmhi, lmlo;
lmlo = lmins & PNG_LOMASK;
lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
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for (j = 0; j < num_p_filters; j++)
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{
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if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH)
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{
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lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
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PNG_WEIGHT_SHIFT;
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lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
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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
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for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1,
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pp = prev_row + 1; i < bpp; i++)
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{
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v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
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sum += (v < 128) ? v : 256 - v;
}
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1998-05-02 17:52:25 +00:00
for (lp = row_buf + 1, cp = prev_row + 1; i < row_bytes; i++)
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{
int a, b, c, pa, pb, pc, p;
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1998-05-02 17:52:25 +00:00
b = *pp++;
c = *cp++;
a = *lp++;
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#ifndef PNG_SLOW_PAETH
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p = b - c;
pc = a - c;
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#ifdef PNG_USE_ABS
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pa = abs(p);
pb = abs(pc);
pc = abs(p + pc);
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#else
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pa = p < 0 ? -p : p;
pb = pc < 0 ? -pc : pc;
pc = (p + pc) < 0 ? -(p + pc) : p + pc;
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#endif
p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c;
#else /* PNG_SLOW_PAETH */
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p = a + b - c;
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pa = abs(p - a);
pb = abs(p - b);
pc = abs(p - c);
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if (pa <= pb && pa <= pc)
p = a;
else if (pb <= pc)
p = b;
else
p = c;
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#endif /* PNG_SLOW_PAETH */
1995-09-26 10:22:39 +00:00
1998-05-02 17:52:25 +00:00
v = *dp++ = (png_byte)(((int)*rp++ - p) & 0xff);
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1996-06-05 20:50:50 +00:00
sum += (v < 128) ? v : 256 - v;
1997-05-16 07:46:07 +00:00
if (sum > lmins) /* We are already worse, don't continue. */
break;
1996-06-05 20:50:50 +00:00
}
1997-05-16 07:46:07 +00:00
#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
1997-05-16 07:46:07 +00:00
if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
{
1998-05-09 15:02:29 +00:00
int j;
1997-05-16 07:46:07 +00:00
png_uint_32 sumhi, sumlo;
sumlo = sum & PNG_LOMASK;
sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
1998-05-02 17:52:25 +00:00
for (j = 0; j < num_p_filters; j++)
1997-05-16 07:46:07 +00:00
{
1998-05-02 17:52:25 +00:00
if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH)
1997-05-16 07:46:07 +00:00
{
1998-05-02 17:52:25 +00:00
sumlo = (sumlo * png_ptr->filter_weights[j]) >>
1997-05-16 07:46:07 +00:00
PNG_WEIGHT_SHIFT;
1998-05-02 17:52:25 +00:00
sumhi = (sumhi * png_ptr->filter_weights[j]) >>
1997-05-16 07:46:07 +00:00
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
1996-06-05 20:50:50 +00:00
if (sum < mins)
{
best_row = png_ptr->paeth_row;
}
1995-09-26 10:22:39 +00:00
}
#endif /* PNG_WRITE_FILTER_SUPPORTED */
1997-05-16 07:46:07 +00:00
/* Do the actual writing of the filtered row data from the chosen filter. */
1998-04-21 20:03:57 +00:00
1996-06-05 20:50:50 +00:00
png_write_filtered_row(png_ptr, best_row);
1997-05-16 07:46:07 +00:00
#ifdef PNG_WRITE_FILTER_SUPPORTED
#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
1997-05-16 07:46:07 +00:00
/* Save the type of filter we picked this time for future calculations */
if (png_ptr->num_prev_filters > 0)
{
1998-05-02 17:52:25 +00:00
int j;
for (j = 1; j < num_p_filters; j++)
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{
1998-05-02 17:52:25 +00:00
png_ptr->prev_filters[j] = png_ptr->prev_filters[j - 1];
1997-05-16 07:46:07 +00:00
}
1998-05-02 17:52:25 +00:00
png_ptr->prev_filters[j] = best_row[0];
1997-05-16 07:46:07 +00:00
}
#endif
#endif /* PNG_WRITE_FILTER_SUPPORTED */
1996-06-05 20:50:50 +00:00
}
1995-07-20 07:43:20 +00:00
1995-09-26 10:22:39 +00:00
1997-05-16 07:46:07 +00:00
/* Do the actual writing of a previously filtered row. */
2000-05-06 19:09:57 +00:00
void /* PRIVATE */
1996-06-05 20:50:50 +00:00
png_write_filtered_row(png_structp png_ptr, png_bytep filtered_row)
{
2008-12-01 14:58:57 +00:00
png_debug(1, "in png_write_filtered_row");
2008-12-01 14:58:57 +00:00
png_debug1(2, "filter = %d", filtered_row[0]);
2009-05-20 17:43:52 +00:00
/* Set up the zlib input buffer */
2000-11-10 18:26:19 +00:00
1997-01-17 07:34:35 +00:00
png_ptr->zstream.next_in = filtered_row;
png_ptr->zstream.avail_in = (uInt)png_ptr->row_info.rowbytes + 1;
2009-05-20 17:43:52 +00:00
/* Repeat until we have compressed all the data */
1996-06-05 20:50:50 +00:00
do
1995-09-26 10:22:39 +00:00
{
2009-05-20 17:43:52 +00:00
int ret; /* Return of zlib */
1995-07-20 07:43:20 +00:00
2009-05-20 17:43:52 +00:00
/* Compress the data */
1997-01-17 07:34:35 +00:00
ret = deflate(&png_ptr->zstream, Z_NO_FLUSH);
2009-05-20 17:43:52 +00:00
/* Check for compression errors */
1996-06-05 20:50:50 +00:00
if (ret != Z_OK)
{
1997-05-16 07:46:07 +00:00
if (png_ptr->zstream.msg != NULL)
1997-01-17 07:34:35 +00:00
png_error(png_ptr, png_ptr->zstream.msg);
1996-06-05 20:50:50 +00:00
else
png_error(png_ptr, "zlib error");
}
1995-07-20 07:43:20 +00:00
2009-05-20 17:43:52 +00:00
/* See if it is time to write another IDAT */
1997-05-16 07:46:07 +00:00
if (!(png_ptr->zstream.avail_out))
1996-06-05 20:50:50 +00:00
{
2009-05-20 17:43:52 +00:00
/* Write the IDAT and reset the zlib output buffer */
1996-06-05 20:50:50 +00:00
png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size);
1997-01-17 07:34:35 +00:00
png_ptr->zstream.next_out = png_ptr->zbuf;
png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
1996-06-05 20:50:50 +00:00
}
2009-05-20 17:43:52 +00:00
/* Repeat until all data has been compressed */
1997-01-17 07:34:35 +00:00
} while (png_ptr->zstream.avail_in);
1995-07-20 07:43:20 +00:00
2009-05-20 17:43:52 +00:00
/* Swap the current and previous rows */
1997-05-16 07:46:07 +00:00
if (png_ptr->prev_row != NULL)
1996-06-17 21:24:45 +00:00
{
png_bytep tptr;
tptr = png_ptr->prev_row;
png_ptr->prev_row = png_ptr->row_buf;
png_ptr->row_buf = tptr;
}
2009-05-20 17:43:52 +00:00
/* Finish row - updates counters and flushes zlib if last row */
1996-06-05 20:50:50 +00:00
png_write_finish_row(png_ptr);
1995-07-20 07:43:20 +00:00
#ifdef PNG_WRITE_FLUSH_SUPPORTED
1996-06-05 20:50:50 +00:00
png_ptr->flush_rows++;
if (png_ptr->flush_dist > 0 &&
png_ptr->flush_rows >= png_ptr->flush_dist)
{
png_write_flush(png_ptr);
1995-07-20 07:43:20 +00:00
}
1999-12-10 15:43:02 +00:00
#endif
1995-07-20 07:43:20 +00:00
}
2001-05-07 19:52:45 +00:00
#endif /* PNG_WRITE_SUPPORTED */