void /* PRIVATE */
png_process_IDAT_data(png_structp png_ptr, png_bytep buffer,
png_size_t buffer_length)
{
int ret;
if ((png_ptr->flags & PNG_FLAG_ZLIB_FINISHED) && buffer_length)
png_error(png_ptr, "Extra compression data");
png_ptr->zstream.next_in = buffer;
png_ptr->zstream.avail_in = (uInt)buffer_length;
for(;;)
{
ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
if (ret != Z_OK)
{
if (ret == Z_STREAM_END)
{
if (png_ptr->zstream.avail_in)
png_error(png_ptr, "Extra compressed data");
if (!(png_ptr->zstream.avail_out))
{
png_push_process_row(png_ptr);
}
png_ptr->mode |= PNG_AFTER_IDAT;
png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
break;
}
else if (ret == Z_BUF_ERROR)
break;
else
png_error(png_ptr, "Decompression Error");
}
if (!(png_ptr->zstream.avail_out))
{
if ((
#if defined(PNG_READ_INTERLACING_SUPPORTED)
png_ptr->interlaced && png_ptr->pass > 6) ||
(!png_ptr->interlaced &&
#endif
png_ptr->row_number == png_ptr->num_rows))
{
if (png_ptr->zstream.avail_in)
{
png_warning(png_ptr, "Too much data in IDAT chunks");
}
png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
break;
}
png_push_process_row(png_ptr);
png_ptr->zstream.avail_out = (uInt)png_ptr->irowbytes;
png_ptr->zstream.next_out = png_ptr->row_buf;
}
else
break;
}
}
void /* PRIVATE */
png_process_IDAT_data(png_structp png_ptr, png_bytep buffer,
png_size_t buffer_length)
{
int ret;
if ((png_ptr->flags & PNG_FLAG_ZLIB_FINISHED) && buffer_length)
png_error(png_ptr, "Extra compression data");
png_ptr->zstream.next_in = buffer;
png_ptr->zstream.avail_in = (uInt)buffer_length;
for(;;)
{
ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
if (ret != Z_OK)
{
if (ret == Z_STREAM_END)
{
if (png_ptr->zstream.avail_in)
png_error(png_ptr, "Extra compressed data");
if (!(png_ptr->zstream.avail_out))
{
png_push_process_row(png_ptr);
}
png_ptr->mode |= PNG_AFTER_IDAT;
png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
break;
}
else if (ret == Z_BUF_ERROR)
break;
else
png_error(png_ptr, "Decompression Error");
}
if (!(png_ptr->zstream.avail_out))
{
png_push_process_row(png_ptr);
png_ptr->zstream.avail_out = (uInt)png_ptr->irowbytes;
png_ptr->zstream.next_out = png_ptr->row_buf;
}
else
break;
}
}
void /* PRIVATE */
png_process_IDAT_data(png_structp png_ptr, png_bytep buffer,
png_size_t buffer_length)
{
/* The caller checks for a non-zero buffer length. */
if (!(buffer_length > 0) || buffer == NULL)
png_error(png_ptr, "No IDAT data (internal error)");
/* This routine must process all the data it has been given
* before returning, calling the row callback as required to
* handle the uncompressed results.
*/
png_ptr->zstream.next_in = buffer;
png_ptr->zstream.avail_in = (uInt)buffer_length;
/* Keep going until the decompressed data is all processed
* or the stream marked as finished.
*/
while (png_ptr->zstream.avail_in > 0 &&
!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
{
int ret;
/* We have data for zlib, but we must check that zlib
* has somewhere to put the results. It doesn't matter
* if we don't expect any results -- it may be the input
* data is just the LZ end code.
*/
if (!(png_ptr->zstream.avail_out > 0))
{
png_ptr->zstream.avail_out =
(uInt) PNG_ROWBYTES(png_ptr->pixel_depth,
png_ptr->iwidth) + 1;
png_ptr->zstream.next_out = png_ptr->row_buf;
}
/* Using Z_SYNC_FLUSH here means that an unterminated
* LZ stream can still be handled (a stream with a missing
* end code), otherwise (Z_NO_FLUSH) a future zlib
* implementation might defer output and, therefore,
* change the current behavior. (See comments in inflate.c
* for why this doesn't happen at present with zlib 1.2.5.)
*/
ret = inflate(&png_ptr->zstream, Z_SYNC_FLUSH);
/* Check for any failure before proceeding. */
if (ret != Z_OK && ret != Z_STREAM_END)
{
/* Terminate the decompression. */
png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
/* This may be a truncated stream (missing or
* damaged end code). Treat that as a warning.
*/
if (png_ptr->row_number >= png_ptr->num_rows ||
png_ptr->pass > 6)
png_warning(png_ptr, "Truncated compressed data in IDAT");
else
png_error(png_ptr, "Decompression error in IDAT");
/* Skip the check on unprocessed input */
return;
}
/* Did inflate output any data? */
if (png_ptr->zstream.next_out != png_ptr->row_buf)
{
/* Is this unexpected data after the last row?
* If it is, artificially terminate the LZ output
* here.
*/
if (png_ptr->row_number >= png_ptr->num_rows ||
png_ptr->pass > 6)
{
/* Extra data. */
png_warning(png_ptr, "Extra compressed data in IDAT");
png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
/* Do no more processing; skip the unprocessed
* input check below.
*/
return;
}
/* Do we have a complete row? */
if (png_ptr->zstream.avail_out == 0)
png_push_process_row(png_ptr);
}
/* And check for the end of the stream. */
if (ret == Z_STREAM_END)
png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
}
/* All the data should have been processed, if anything
* is left at this point we have bytes of IDAT data
* after the zlib end code.
*/
if (png_ptr->zstream.avail_in > 0)
png_warning(png_ptr, "Extra compression data");
}
void /* PRIVATE */
png_process_IDAT_data(png_structrp png_ptr, png_bytep buffer,
png_size_t buffer_length)
{
/* The caller checks for a non-zero buffer length. */
if (!(buffer_length > 0) || buffer == NULL)
png_error(png_ptr, "No IDAT data (internal error)");
#ifdef PNG_READ_APNG_SUPPORTED
/* If the app is not APNG-aware, decode only the first frame */
if ((png_ptr->apng_flags & PNG_APNG_APP) == 0 &&
png_ptr->num_frames_read > 0)
{
png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED;
return;
}
#endif
/* This routine must process all the data it has been given
* before returning, calling the row callback as required to
* handle the uncompressed results.
*/
png_ptr->zstream.next_in = buffer;
/* TODO: WARNING: TRUNCATION ERROR: DANGER WILL ROBINSON: */
png_ptr->zstream.avail_in = (uInt)buffer_length;
/* Keep going until the decompressed data is all processed
* or the stream marked as finished.
*/
while (png_ptr->zstream.avail_in > 0 &&
(png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED) == 0)
{
int ret;
/* We have data for zlib, but we must check that zlib
* has someplace to put the results. It doesn't matter
* if we don't expect any results -- it may be the input
* data is just the LZ end code.
*/
if (!(png_ptr->zstream.avail_out > 0))
{
/* TODO: WARNING: TRUNCATION ERROR: DANGER WILL ROBINSON: */
png_ptr->zstream.avail_out = (uInt)(PNG_ROWBYTES(png_ptr->pixel_depth,
png_ptr->iwidth) + 1);
png_ptr->zstream.next_out = png_ptr->row_buf;
}
/* Using Z_SYNC_FLUSH here means that an unterminated
* LZ stream (a stream with a missing end code) can still
* be handled, otherwise (Z_NO_FLUSH) a future zlib
* implementation might defer output and therefore
* change the current behavior (see comments in inflate.c
* for why this doesn't happen at present with zlib 1.2.5).
*/
ret = PNG_INFLATE(png_ptr, Z_SYNC_FLUSH);
/* Check for any failure before proceeding. */
if (ret != Z_OK && ret != Z_STREAM_END)
{
/* Terminate the decompression. */
png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED;
png_ptr->zowner = 0;
/* This may be a truncated stream (missing or
* damaged end code). Treat that as a warning.
*/
if (png_ptr->row_number >= png_ptr->num_rows ||
png_ptr->pass > 6)
png_warning(png_ptr, "Truncated compressed data in IDAT");
else
{
if (ret == Z_DATA_ERROR)
png_benign_error(png_ptr, "IDAT: ADLER32 checksum mismatch");
else
png_error(png_ptr, "Decompression error in IDAT");
}
/* Skip the check on unprocessed input */
return;
}
/* Did inflate output any data? */
if (png_ptr->zstream.next_out != png_ptr->row_buf)
{
/* Is this unexpected data after the last row?
* If it is, artificially terminate the LZ output
* here.
*/
if (png_ptr->row_number >= png_ptr->num_rows ||
png_ptr->pass > 6)
{
/* Extra data. */
png_warning(png_ptr, "Extra compressed data in IDAT");
png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED;
png_ptr->zowner = 0;
/* Do no more processing; skip the unprocessed
* input check below.
*/
return;
}
/* Do we have a complete row? */
if (png_ptr->zstream.avail_out == 0)
png_push_process_row(png_ptr);
}
/* And check for the end of the stream. */
if (ret == Z_STREAM_END)
png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED;
}
/* All the data should have been processed, if anything
* is left at this point we have bytes of IDAT data
* after the zlib end code.
*/
if (png_ptr->zstream.avail_in > 0)
png_warning(png_ptr, "Extra compression data in IDAT");
}
