/*
* Extension to libpng's unknown chunk handler.
*/
static void opng_set_keep_unknown_chunk(png_structp png_ptr, int keep, png_bytep chunk_type)
{
png_byte chunk_name[5];
/* Call png_set_keep_unknown_chunks() once per each chunk type only. */
memcpy(chunk_name, chunk_type, 4);
chunk_name[4] = 0;
if (!png_handle_as_unknown(png_ptr, chunk_name))
png_set_keep_unknown_chunks(png_ptr, keep, chunk_name, 1);
}
/* Read the end of the PNG file. Will not read past the end of the
* file, will verify the end is accurate, and will read any comments
* or time information at the end of the file, if info is not NULL.
*/
void PNGAPI
png_read_end(png_structp png_ptr, png_infop info_ptr)
{
png_debug(1, "in png_read_end");
if (png_ptr == NULL)
return;
png_crc_finish(png_ptr, 0); /* Finish off CRC from last IDAT chunk */
do
{
PNG_IHDR;
PNG_IDAT;
PNG_IEND;
PNG_PLTE;
#ifdef PNG_READ_bKGD_SUPPORTED
PNG_bKGD;
#endif
#ifdef PNG_READ_cHRM_SUPPORTED
PNG_cHRM;
#endif
#ifdef PNG_READ_gAMA_SUPPORTED
PNG_gAMA;
#endif
#ifdef PNG_READ_hIST_SUPPORTED
PNG_hIST;
#endif
#ifdef PNG_READ_iCCP_SUPPORTED
PNG_iCCP;
#endif
#ifdef PNG_READ_iTXt_SUPPORTED
PNG_iTXt;
#endif
#ifdef PNG_READ_oFFs_SUPPORTED
PNG_oFFs;
#endif
#ifdef PNG_READ_pCAL_SUPPORTED
PNG_pCAL;
#endif
#ifdef PNG_READ_pHYs_SUPPORTED
PNG_pHYs;
#endif
#ifdef PNG_READ_sBIT_SUPPORTED
PNG_sBIT;
#endif
#ifdef PNG_READ_sCAL_SUPPORTED
PNG_sCAL;
#endif
#ifdef PNG_READ_sPLT_SUPPORTED
PNG_sPLT;
#endif
#ifdef PNG_READ_sRGB_SUPPORTED
PNG_sRGB;
#endif
#ifdef PNG_READ_tEXt_SUPPORTED
PNG_tEXt;
#endif
#ifdef PNG_READ_tIME_SUPPORTED
PNG_tIME;
#endif
#ifdef PNG_READ_tRNS_SUPPORTED
PNG_tRNS;
#endif
#ifdef PNG_READ_zTXt_SUPPORTED
PNG_zTXt;
#endif
png_uint_32 length = png_read_chunk_header(png_ptr);
PNG_CONST png_bytep chunk_name = png_ptr->chunk_name;
if (!png_memcmp(chunk_name, png_IHDR, 4))
png_handle_IHDR(png_ptr, info_ptr, length);
else if (!png_memcmp(chunk_name, png_IEND, 4))
png_handle_IEND(png_ptr, info_ptr, length);
#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
else if (png_handle_as_unknown(png_ptr, chunk_name))
{
if (!png_memcmp(chunk_name, png_IDAT, 4))
{
if ((length > 0) || (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT))
png_benign_error(png_ptr, "Too many IDATs found");
}
png_handle_unknown(png_ptr, info_ptr, length);
if (!png_memcmp(chunk_name, png_PLTE, 4))
png_ptr->mode |= PNG_HAVE_PLTE;
}
#endif
else if (!png_memcmp(chunk_name, png_IDAT, 4))
{
/* Zero length IDATs are legal after the last IDAT has been
* read, but not after other chunks have been read.
*/
if ((length > 0) || (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT))
png_benign_error(png_ptr, "Too many IDATs found");
png_crc_finish(png_ptr, length);
}
else if (!png_memcmp(chunk_name, png_PLTE, 4))
png_handle_PLTE(png_ptr, info_ptr, length);
#ifdef PNG_READ_bKGD_SUPPORTED
else if (!png_memcmp(chunk_name, png_bKGD, 4))
png_handle_bKGD(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_cHRM_SUPPORTED
else if (!png_memcmp(chunk_name, png_cHRM, 4))
png_handle_cHRM(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_gAMA_SUPPORTED
else if (!png_memcmp(chunk_name, png_gAMA, 4))
png_handle_gAMA(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_hIST_SUPPORTED
else if (!png_memcmp(chunk_name, png_hIST, 4))
png_handle_hIST(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_oFFs_SUPPORTED
else if (!png_memcmp(chunk_name, png_oFFs, 4))
png_handle_oFFs(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_pCAL_SUPPORTED
else if (!png_memcmp(chunk_name, png_pCAL, 4))
png_handle_pCAL(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_sCAL_SUPPORTED
else if (!png_memcmp(chunk_name, png_sCAL, 4))
png_handle_sCAL(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_pHYs_SUPPORTED
else if (!png_memcmp(chunk_name, png_pHYs, 4))
png_handle_pHYs(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_sBIT_SUPPORTED
else if (!png_memcmp(chunk_name, png_sBIT, 4))
png_handle_sBIT(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_sRGB_SUPPORTED
else if (!png_memcmp(chunk_name, png_sRGB, 4))
png_handle_sRGB(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_iCCP_SUPPORTED
else if (!png_memcmp(chunk_name, png_iCCP, 4))
png_handle_iCCP(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_sPLT_SUPPORTED
else if (!png_memcmp(chunk_name, png_sPLT, 4))
png_handle_sPLT(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_tEXt_SUPPORTED
else if (!png_memcmp(chunk_name, png_tEXt, 4))
png_handle_tEXt(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_tIME_SUPPORTED
else if (!png_memcmp(chunk_name, png_tIME, 4))
png_handle_tIME(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_tRNS_SUPPORTED
else if (!png_memcmp(chunk_name, png_tRNS, 4))
png_handle_tRNS(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_zTXt_SUPPORTED
else if (!png_memcmp(chunk_name, png_zTXt, 4))
png_handle_zTXt(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_iTXt_SUPPORTED
else if (!png_memcmp(chunk_name, png_iTXt, 4))
png_handle_iTXt(png_ptr, info_ptr, length);
#endif
else
png_handle_unknown(png_ptr, info_ptr, length);
} while (!(png_ptr->mode & PNG_HAVE_IEND));
}
/* Read the information before the actual image data. This has been
* changed in v0.90 to allow reading a file that already has the magic
* bytes read from the stream. You can tell libpng how many bytes have
* been read from the beginning of the stream (up to the maximum of 8)
* via png_set_sig_bytes(), and we will only check the remaining bytes
* here. The application can then have access to the signature bytes we
* read if it is determined that this isn't a valid PNG file.
*/
void PNGAPI
png_read_info(png_structp png_ptr, png_infop info_ptr)
{
png_debug(1, "in png_read_info");
if (png_ptr == NULL || info_ptr == NULL)
return;
/* Read and check the PNG file signature. */
png_read_sig(png_ptr, info_ptr);
for (;;)
{
PNG_IHDR;
PNG_IDAT;
PNG_IEND;
PNG_PLTE;
#ifdef PNG_READ_bKGD_SUPPORTED
PNG_bKGD;
#endif
#ifdef PNG_READ_cHRM_SUPPORTED
PNG_cHRM;
#endif
#ifdef PNG_READ_gAMA_SUPPORTED
PNG_gAMA;
#endif
#ifdef PNG_READ_hIST_SUPPORTED
PNG_hIST;
#endif
#ifdef PNG_READ_iCCP_SUPPORTED
PNG_iCCP;
#endif
#ifdef PNG_READ_iTXt_SUPPORTED
PNG_iTXt;
#endif
#ifdef PNG_READ_oFFs_SUPPORTED
PNG_oFFs;
#endif
#ifdef PNG_READ_pCAL_SUPPORTED
PNG_pCAL;
#endif
#ifdef PNG_READ_pHYs_SUPPORTED
PNG_pHYs;
#endif
#ifdef PNG_READ_sBIT_SUPPORTED
PNG_sBIT;
#endif
#ifdef PNG_READ_sCAL_SUPPORTED
PNG_sCAL;
#endif
#ifdef PNG_READ_sPLT_SUPPORTED
PNG_sPLT;
#endif
#ifdef PNG_READ_sRGB_SUPPORTED
PNG_sRGB;
#endif
#ifdef PNG_READ_tEXt_SUPPORTED
PNG_tEXt;
#endif
#ifdef PNG_READ_tIME_SUPPORTED
PNG_tIME;
#endif
#ifdef PNG_READ_tRNS_SUPPORTED
PNG_tRNS;
#endif
#ifdef PNG_READ_zTXt_SUPPORTED
PNG_zTXt;
#endif
png_uint_32 length = png_read_chunk_header(png_ptr);
PNG_CONST png_bytep chunk_name = png_ptr->chunk_name;
/* This should be a binary subdivision search or a hash for
* matching the chunk name rather than a linear search.
*/
if (!png_memcmp(chunk_name, png_IDAT, 4))
if (png_ptr->mode & PNG_AFTER_IDAT)
png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT;
if (!png_memcmp(chunk_name, png_IHDR, 4))
png_handle_IHDR(png_ptr, info_ptr, length);
else if (!png_memcmp(chunk_name, png_IEND, 4))
png_handle_IEND(png_ptr, info_ptr, length);
#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
else if (png_handle_as_unknown(png_ptr, chunk_name))
{
if (!png_memcmp(chunk_name, png_IDAT, 4))
png_ptr->mode |= PNG_HAVE_IDAT;
png_handle_unknown(png_ptr, info_ptr, length);
if (!png_memcmp(chunk_name, png_PLTE, 4))
png_ptr->mode |= PNG_HAVE_PLTE;
else if (!png_memcmp(chunk_name, png_IDAT, 4))
{
if (!(png_ptr->mode & PNG_HAVE_IHDR))
png_error(png_ptr, "Missing IHDR before IDAT");
else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
!(png_ptr->mode & PNG_HAVE_PLTE))
png_error(png_ptr, "Missing PLTE before IDAT");
break;
}
}
#endif
else if (!png_memcmp(chunk_name, png_PLTE, 4))
png_handle_PLTE(png_ptr, info_ptr, length);
else if (!png_memcmp(chunk_name, png_IDAT, 4))
{
if (!(png_ptr->mode & PNG_HAVE_IHDR))
png_error(png_ptr, "Missing IHDR before IDAT");
else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
!(png_ptr->mode & PNG_HAVE_PLTE))
png_error(png_ptr, "Missing PLTE before IDAT");
png_ptr->idat_size = length;
png_ptr->mode |= PNG_HAVE_IDAT;
break;
}
#ifdef PNG_READ_bKGD_SUPPORTED
else if (!png_memcmp(chunk_name, png_bKGD, 4))
png_handle_bKGD(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_cHRM_SUPPORTED
else if (!png_memcmp(chunk_name, png_cHRM, 4))
png_handle_cHRM(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_gAMA_SUPPORTED
else if (!png_memcmp(chunk_name, png_gAMA, 4))
png_handle_gAMA(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_hIST_SUPPORTED
else if (!png_memcmp(chunk_name, png_hIST, 4))
png_handle_hIST(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_oFFs_SUPPORTED
else if (!png_memcmp(chunk_name, png_oFFs, 4))
png_handle_oFFs(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_pCAL_SUPPORTED
else if (!png_memcmp(chunk_name, png_pCAL, 4))
png_handle_pCAL(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_sCAL_SUPPORTED
else if (!png_memcmp(chunk_name, png_sCAL, 4))
png_handle_sCAL(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_pHYs_SUPPORTED
else if (!png_memcmp(chunk_name, png_pHYs, 4))
png_handle_pHYs(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_sBIT_SUPPORTED
else if (!png_memcmp(chunk_name, png_sBIT, 4))
png_handle_sBIT(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_sRGB_SUPPORTED
else if (!png_memcmp(chunk_name, png_sRGB, 4))
png_handle_sRGB(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_iCCP_SUPPORTED
else if (!png_memcmp(chunk_name, png_iCCP, 4))
png_handle_iCCP(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_sPLT_SUPPORTED
else if (!png_memcmp(chunk_name, png_sPLT, 4))
png_handle_sPLT(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_tEXt_SUPPORTED
else if (!png_memcmp(chunk_name, png_tEXt, 4))
png_handle_tEXt(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_tIME_SUPPORTED
else if (!png_memcmp(chunk_name, png_tIME, 4))
png_handle_tIME(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_tRNS_SUPPORTED
else if (!png_memcmp(chunk_name, png_tRNS, 4))
png_handle_tRNS(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_zTXt_SUPPORTED
else if (!png_memcmp(chunk_name, png_zTXt, 4))
png_handle_zTXt(png_ptr, info_ptr, length);
#endif
#ifdef PNG_READ_iTXt_SUPPORTED
else if (!png_memcmp(chunk_name, png_iTXt, 4))
png_handle_iTXt(png_ptr, info_ptr, length);
#endif
else
png_handle_unknown(png_ptr, info_ptr, length);
}
}
/* This function is called when we haven't found a handler for this
* chunk. If there isn't a problem with the chunk itself (ie a bad chunk
* name or a critical chunk), the chunk is (currently) silently ignored.
*/
void /* PRIVATE */
png_push_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32
length)
{
png_uint_32 skip=0;
png_check_chunk_name(png_ptr, png_ptr->chunk_name);
if (!(png_ptr->chunk_name[0] & 0x20))
{
#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
if(png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
PNG_HANDLE_CHUNK_ALWAYS
#if defined(PNG_READ_USER_CHUNKS_SUPPORTED)
&& png_ptr->read_user_chunk_fn == NULL
#endif
)
#endif
png_chunk_error(png_ptr, "unknown critical chunk");
(void) info_ptr; /* to quiet some compiler warnings */
}
#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
if (png_ptr->flags & PNG_FLAG_KEEP_UNKNOWN_CHUNKS)
{
#ifdef PNG_MAX_MALLOC_64K
if (length > (png_uint_32)65535L)
{
png_warning(png_ptr, "unknown chunk too large to fit in memory");
skip = length - (png_uint_32)65535L;
length = (png_uint_32)65535L;
}
#endif
png_strncpy((png_charp)png_ptr->unknown_chunk.name,
(png_charp)png_ptr->chunk_name, 5);
png_ptr->unknown_chunk.data = (png_bytep)png_malloc(png_ptr, length);
png_ptr->unknown_chunk.size = (png_size_t)length;
png_crc_read(png_ptr, (png_bytep)png_ptr->unknown_chunk.data, length);
#if defined(PNG_READ_USER_CHUNKS_SUPPORTED)
if(png_ptr->read_user_chunk_fn != NULL)
{
/* callback to user unknown chunk handler */
int ret;
ret = (*(png_ptr->read_user_chunk_fn))
(png_ptr, &png_ptr->unknown_chunk);
if (ret < 0)
png_chunk_error(png_ptr, "error in user chunk");
if (ret == 0)
{
if (!(png_ptr->chunk_name[0] & 0x20))
if(png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
PNG_HANDLE_CHUNK_ALWAYS)
png_chunk_error(png_ptr, "unknown critical chunk");
png_set_unknown_chunks(png_ptr, info_ptr,
&png_ptr->unknown_chunk, 1);
}
}
#else
png_set_unknown_chunks(png_ptr, info_ptr, &png_ptr->unknown_chunk, 1);
#endif
png_free(png_ptr, png_ptr->unknown_chunk.data);
png_ptr->unknown_chunk.data = NULL;
}
else
#endif
skip=length;
png_push_crc_skip(png_ptr, skip);
}
void /* PRIVATE */
png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
{
#ifdef PNG_USE_LOCAL_ARRAYS
PNG_CONST PNG_IHDR;
PNG_CONST PNG_IDAT;
PNG_CONST PNG_IEND;
PNG_CONST PNG_PLTE;
#if defined(PNG_READ_bKGD_SUPPORTED)
PNG_CONST PNG_bKGD;
#endif
#if defined(PNG_READ_cHRM_SUPPORTED)
PNG_CONST PNG_cHRM;
#endif
#if defined(PNG_READ_gAMA_SUPPORTED)
PNG_CONST PNG_gAMA;
#endif
#if defined(PNG_READ_hIST_SUPPORTED)
PNG_CONST PNG_hIST;
#endif
#if defined(PNG_READ_iCCP_SUPPORTED)
PNG_CONST PNG_iCCP;
#endif
#if defined(PNG_READ_iTXt_SUPPORTED)
PNG_CONST PNG_iTXt;
#endif
#if defined(PNG_READ_oFFs_SUPPORTED)
PNG_CONST PNG_oFFs;
#endif
#if defined(PNG_READ_pCAL_SUPPORTED)
PNG_CONST PNG_pCAL;
#endif
#if defined(PNG_READ_pHYs_SUPPORTED)
PNG_CONST PNG_pHYs;
#endif
#if defined(PNG_READ_sBIT_SUPPORTED)
PNG_CONST PNG_sBIT;
#endif
#if defined(PNG_READ_sCAL_SUPPORTED)
PNG_CONST PNG_sCAL;
#endif
#if defined(PNG_READ_sRGB_SUPPORTED)
PNG_CONST PNG_sRGB;
#endif
#if defined(PNG_READ_sPLT_SUPPORTED)
PNG_CONST PNG_sPLT;
#endif
#if defined(PNG_READ_tEXt_SUPPORTED)
PNG_CONST PNG_tEXt;
#endif
#if defined(PNG_READ_tIME_SUPPORTED)
PNG_CONST PNG_tIME;
#endif
#if defined(PNG_READ_tRNS_SUPPORTED)
PNG_CONST PNG_tRNS;
#endif
#if defined(PNG_READ_zTXt_SUPPORTED)
PNG_CONST PNG_zTXt;
#endif
#endif /* PNG_USE_LOCAL_ARRAYS */
/* First we make sure we have enough data for the 4 byte chunk name
* and the 4 byte chunk length before proceeding with decoding the
* chunk data. To fully decode each of these chunks, we also make
* sure we have enough data in the buffer for the 4 byte CRC at the
* end of every chunk (except IDAT, which is handled separately).
*/
if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER))
{
png_byte chunk_length[4];
if (png_ptr->buffer_size < 8)
{
png_push_save_buffer(png_ptr);
return;
}
png_push_fill_buffer(png_ptr, chunk_length, 4);
png_ptr->push_length = png_get_uint_31(png_ptr,chunk_length);
png_reset_crc(png_ptr);
png_crc_read(png_ptr, png_ptr->chunk_name, 4);
png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
}
if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
if(png_ptr->mode & PNG_AFTER_IDAT)
png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT;
if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4))
{
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
{
png_push_save_buffer(png_ptr);
return;
}
png_handle_IHDR(png_ptr, info_ptr, png_ptr->push_length);
}
else if (!png_memcmp(png_ptr->chunk_name, png_IEND, 4))
{
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
{
png_push_save_buffer(png_ptr);
return;
}
png_handle_IEND(png_ptr, info_ptr, png_ptr->push_length);
png_ptr->process_mode = PNG_READ_DONE_MODE;
png_push_have_end(png_ptr, info_ptr);
}
#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
else if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name))
{
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
{
png_push_save_buffer(png_ptr);
return;
}
if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
png_ptr->mode |= PNG_HAVE_IDAT;
png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length);
if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
png_ptr->mode |= PNG_HAVE_PLTE;
else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
{
if (!(png_ptr->mode & PNG_HAVE_IHDR))
png_error(png_ptr, "Missing IHDR before IDAT");
else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
!(png_ptr->mode & PNG_HAVE_PLTE))
png_error(png_ptr, "Missing PLTE before IDAT");
}
}
#endif
else if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
{
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
{
png_push_save_buffer(png_ptr);
return;
}
png_handle_PLTE(png_ptr, info_ptr, png_ptr->push_length);
}
else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
{
/* If we reach an IDAT chunk, this means we have read all of the
* header chunks, and we can start reading the image (or if this
* is called after the image has been read - we have an error).
*/
if (!(png_ptr->mode & PNG_HAVE_IHDR))
png_error(png_ptr, "Missing IHDR before IDAT");
else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
!(png_ptr->mode & PNG_HAVE_PLTE))
png_error(png_ptr, "Missing PLTE before IDAT");
if (png_ptr->mode & PNG_HAVE_IDAT)
{
if (!(png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT))
if (png_ptr->push_length == 0)
return;
if (png_ptr->mode & PNG_AFTER_IDAT)
png_error(png_ptr, "Too many IDAT's found");
}
png_ptr->idat_size = png_ptr->push_length;
png_ptr->mode |= PNG_HAVE_IDAT;
png_ptr->process_mode = PNG_READ_IDAT_MODE;
png_push_have_info(png_ptr, info_ptr);
png_ptr->zstream.avail_out = (uInt)png_ptr->irowbytes;
png_ptr->zstream.next_out = png_ptr->row_buf;
return;
}
#if defined(PNG_READ_gAMA_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_gAMA, 4))
{
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
{
png_push_save_buffer(png_ptr);
return;
}
png_handle_gAMA(png_ptr, info_ptr, png_ptr->push_length);
}
#endif
#if defined(PNG_READ_sBIT_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_sBIT, 4))
{
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
{
png_push_save_buffer(png_ptr);
return;
}
png_handle_sBIT(png_ptr, info_ptr, png_ptr->push_length);
}
#endif
#if defined(PNG_READ_cHRM_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_cHRM, 4))
{
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
{
png_push_save_buffer(png_ptr);
return;
}
png_handle_cHRM(png_ptr, info_ptr, png_ptr->push_length);
}
#endif
#if defined(PNG_READ_sRGB_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4))
{
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
{
png_push_save_buffer(png_ptr);
return;
}
png_handle_sRGB(png_ptr, info_ptr, png_ptr->push_length);
}
#endif
#if defined(PNG_READ_iCCP_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_iCCP, 4))
{
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
{
png_push_save_buffer(png_ptr);
return;
}
png_handle_iCCP(png_ptr, info_ptr, png_ptr->push_length);
}
#endif
#if defined(PNG_READ_sPLT_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_sPLT, 4))
{
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
{
png_push_save_buffer(png_ptr);
return;
}
png_handle_sPLT(png_ptr, info_ptr, png_ptr->push_length);
}
#endif
#if defined(PNG_READ_tRNS_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_tRNS, 4))
{
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
{
png_push_save_buffer(png_ptr);
return;
}
png_handle_tRNS(png_ptr, info_ptr, png_ptr->push_length);
}
#endif
#if defined(PNG_READ_bKGD_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_bKGD, 4))
{
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
{
png_push_save_buffer(png_ptr);
return;
}
png_handle_bKGD(png_ptr, info_ptr, png_ptr->push_length);
}
#endif
#if defined(PNG_READ_hIST_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_hIST, 4))
{
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
{
png_push_save_buffer(png_ptr);
return;
}
png_handle_hIST(png_ptr, info_ptr, png_ptr->push_length);
}
#endif
#if defined(PNG_READ_pHYs_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_pHYs, 4))
{
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
{
png_push_save_buffer(png_ptr);
return;
}
png_handle_pHYs(png_ptr, info_ptr, png_ptr->push_length);
}
#endif
#if defined(PNG_READ_oFFs_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_oFFs, 4))
{
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
{
png_push_save_buffer(png_ptr);
return;
}
png_handle_oFFs(png_ptr, info_ptr, png_ptr->push_length);
}
#endif
#if defined(PNG_READ_pCAL_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_pCAL, 4))
{
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
{
png_push_save_buffer(png_ptr);
return;
}
png_handle_pCAL(png_ptr, info_ptr, png_ptr->push_length);
}
#endif
#if defined(PNG_READ_sCAL_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_sCAL, 4))
{
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
{
png_push_save_buffer(png_ptr);
return;
}
png_handle_sCAL(png_ptr, info_ptr, png_ptr->push_length);
}
#endif
#if defined(PNG_READ_tIME_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_tIME, 4))
{
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
{
png_push_save_buffer(png_ptr);
return;
}
png_handle_tIME(png_ptr, info_ptr, png_ptr->push_length);
}
#endif
#if defined(PNG_READ_tEXt_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4))
{
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
{
png_push_save_buffer(png_ptr);
return;
}
png_push_handle_tEXt(png_ptr, info_ptr, png_ptr->push_length);
}
#endif
#if defined(PNG_READ_zTXt_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_zTXt, 4))
{
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
{
png_push_save_buffer(png_ptr);
return;
}
png_push_handle_zTXt(png_ptr, info_ptr, png_ptr->push_length);
}
#endif
#if defined(PNG_READ_iTXt_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_iTXt, 4))
{
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
{
png_push_save_buffer(png_ptr);
return;
}
png_push_handle_iTXt(png_ptr, info_ptr, png_ptr->push_length);
}
#endif
else
{
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
{
png_push_save_buffer(png_ptr);
return;
}
png_push_handle_unknown(png_ptr, info_ptr, png_ptr->push_length);
}
png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
}
/* Read the information before the actual image data. This has been
* changed in v0.90 to allow reading a file that already has the magic
* bytes read from the stream. You can tell libpng how many bytes have
* been read from the beginning of the stream (up to the maximum of 8)
* via png_set_sig_bytes(), and we will only check the remaining bytes
* here. The application can then have access to the signature bytes we
* read if it is determined that this isn't a valid PNG file.
*/
void PNGAPI
png_read_info(png_structp png_ptr, png_infop info_ptr)
{
if(png_ptr == NULL) return;
png_debug(1, "in png_read_info\n");
/* If we haven't checked all of the PNG signature bytes, do so now. */
if (png_ptr->sig_bytes < 8)
{
png_size_t num_checked = png_ptr->sig_bytes,
num_to_check = 8 - num_checked;
png_read_data(png_ptr, &(info_ptr->signature[num_checked]), num_to_check);
png_ptr->sig_bytes = 8;
if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check))
{
if (num_checked < 4 &&
png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4))
png_error(png_ptr, "Not a PNG file");
else
png_error(png_ptr, "PNG file corrupted by ASCII conversion");
}
if (num_checked < 3)
png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE;
}
for(;;)
{
#ifdef PNG_USE_LOCAL_ARRAYS
PNG_CONST PNG_IHDR;
PNG_CONST PNG_IDAT;
PNG_CONST PNG_IEND;
PNG_CONST PNG_PLTE;
#if defined(PNG_READ_bKGD_SUPPORTED)
PNG_CONST PNG_bKGD;
#endif
#if defined(PNG_READ_cHRM_SUPPORTED)
PNG_CONST PNG_cHRM;
#endif
#if defined(PNG_READ_gAMA_SUPPORTED)
PNG_CONST PNG_gAMA;
#endif
#if defined(PNG_READ_hIST_SUPPORTED)
PNG_CONST PNG_hIST;
#endif
#if defined(PNG_READ_iCCP_SUPPORTED)
PNG_CONST PNG_iCCP;
#endif
#if defined(PNG_READ_iTXt_SUPPORTED)
PNG_CONST PNG_iTXt;
#endif
#if defined(PNG_READ_oFFs_SUPPORTED)
PNG_CONST PNG_oFFs;
#endif
#if defined(PNG_READ_pCAL_SUPPORTED)
PNG_CONST PNG_pCAL;
#endif
#if defined(PNG_READ_pHYs_SUPPORTED)
PNG_CONST PNG_pHYs;
#endif
#if defined(PNG_READ_sBIT_SUPPORTED)
PNG_CONST PNG_sBIT;
#endif
#if defined(PNG_READ_sCAL_SUPPORTED)
PNG_CONST PNG_sCAL;
#endif
#if defined(PNG_READ_sPLT_SUPPORTED)
PNG_CONST PNG_sPLT;
#endif
#if defined(PNG_READ_sRGB_SUPPORTED)
PNG_CONST PNG_sRGB;
#endif
#if defined(PNG_READ_tEXt_SUPPORTED)
PNG_CONST PNG_tEXt;
#endif
#if defined(PNG_READ_tIME_SUPPORTED)
PNG_CONST PNG_tIME;
#endif
#if defined(PNG_READ_tRNS_SUPPORTED)
PNG_CONST PNG_tRNS;
#endif
#if defined(PNG_READ_zTXt_SUPPORTED)
PNG_CONST PNG_zTXt;
#endif
#endif /* PNG_USE_LOCAL_ARRAYS */
png_byte chunk_length[4];
png_uint_32 length;
png_read_data(png_ptr, chunk_length, 4);
length = png_get_uint_31(png_ptr,chunk_length);
png_reset_crc(png_ptr);
png_crc_read(png_ptr, png_ptr->chunk_name, 4);
png_debug2(0, "Reading %s chunk, length=%lu.\n", png_ptr->chunk_name,
length);
/* This should be a binary subdivision search or a hash for
* matching the chunk name rather than a linear search.
*/
if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
if(png_ptr->mode & PNG_AFTER_IDAT)
png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT;
if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4))
png_handle_IHDR(png_ptr, info_ptr, length);
else if (!png_memcmp(png_ptr->chunk_name, png_IEND, 4))
png_handle_IEND(png_ptr, info_ptr, length);
#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
else if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name))
{
if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
png_ptr->mode |= PNG_HAVE_IDAT;
png_handle_unknown(png_ptr, info_ptr, length);
if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
png_ptr->mode |= PNG_HAVE_PLTE;
else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
{
if (!(png_ptr->mode & PNG_HAVE_IHDR))
png_error(png_ptr, "Missing IHDR before IDAT");
else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
!(png_ptr->mode & PNG_HAVE_PLTE))
png_error(png_ptr, "Missing PLTE before IDAT");
break;
}
}
#endif
else if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
png_handle_PLTE(png_ptr, info_ptr, length);
else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
{
if (!(png_ptr->mode & PNG_HAVE_IHDR))
png_error(png_ptr, "Missing IHDR before IDAT");
else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
!(png_ptr->mode & PNG_HAVE_PLTE))
png_error(png_ptr, "Missing PLTE before IDAT");
png_ptr->idat_size = length;
png_ptr->mode |= PNG_HAVE_IDAT;
break;
}
#if defined(PNG_READ_bKGD_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_bKGD, 4))
png_handle_bKGD(png_ptr, info_ptr, length);
#endif
#if defined(PNG_READ_cHRM_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_cHRM, 4))
png_handle_cHRM(png_ptr, info_ptr, length);
#endif
#if defined(PNG_READ_gAMA_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_gAMA, 4))
png_handle_gAMA(png_ptr, info_ptr, length);
#endif
#if defined(PNG_READ_hIST_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_hIST, 4))
png_handle_hIST(png_ptr, info_ptr, length);
#endif
#if defined(PNG_READ_oFFs_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_oFFs, 4))
png_handle_oFFs(png_ptr, info_ptr, length);
#endif
#if defined(PNG_READ_pCAL_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_pCAL, 4))
png_handle_pCAL(png_ptr, info_ptr, length);
#endif
#if defined(PNG_READ_sCAL_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_sCAL, 4))
png_handle_sCAL(png_ptr, info_ptr, length);
#endif
#if defined(PNG_READ_pHYs_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_pHYs, 4))
png_handle_pHYs(png_ptr, info_ptr, length);
#endif
#if defined(PNG_READ_sBIT_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_sBIT, 4))
png_handle_sBIT(png_ptr, info_ptr, length);
#endif
#if defined(PNG_READ_sRGB_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4))
png_handle_sRGB(png_ptr, info_ptr, length);
#endif
#if defined(PNG_READ_iCCP_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_iCCP, 4))
png_handle_iCCP(png_ptr, info_ptr, length);
#endif
#if defined(PNG_READ_sPLT_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_sPLT, 4))
png_handle_sPLT(png_ptr, info_ptr, length);
#endif
#if defined(PNG_READ_tEXt_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4))
png_handle_tEXt(png_ptr, info_ptr, length);
#endif
#if defined(PNG_READ_tIME_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_tIME, 4))
png_handle_tIME(png_ptr, info_ptr, length);
#endif
#if defined(PNG_READ_tRNS_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_tRNS, 4))
png_handle_tRNS(png_ptr, info_ptr, length);
#endif
#if defined(PNG_READ_zTXt_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_zTXt, 4))
png_handle_zTXt(png_ptr, info_ptr, length);
#endif
#if defined(PNG_READ_iTXt_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_iTXt, 4))
png_handle_iTXt(png_ptr, info_ptr, length);
#endif
else
png_handle_unknown(png_ptr, info_ptr, length);
}
}
/* Read the end of the PNG file. Will not read past the end of the
* file, will verify the end is accurate, and will read any comments
* or time information at the end of the file, if info is not NULL.
*/
void PNGAPI
png_read_end(png_structp png_ptr, png_infop info_ptr)
{
png_byte chunk_length[4];
png_uint_32 length;
png_debug(1, "in png_read_end\n");
png_crc_finish(png_ptr, 0); /* Finish off CRC from last IDAT chunk */
do
{
#ifdef PNG_USE_LOCAL_ARRAYS
PNG_IHDR;
PNG_IDAT;
PNG_IEND;
PNG_PLTE;
#if defined(PNG_READ_bKGD_SUPPORTED)
PNG_bKGD;
#endif
#if defined(PNG_READ_cHRM_SUPPORTED)
PNG_cHRM;
#endif
#if defined(PNG_READ_gAMA_SUPPORTED)
PNG_gAMA;
#endif
#if defined(PNG_READ_hIST_SUPPORTED)
PNG_hIST;
#endif
#if defined(PNG_READ_iCCP_SUPPORTED)
PNG_iCCP;
#endif
#if defined(PNG_READ_iTXt_SUPPORTED)
PNG_iTXt;
#endif
#if defined(PNG_READ_oFFs_SUPPORTED)
PNG_oFFs;
#endif
#if defined(PNG_READ_pCAL_SUPPORTED)
PNG_pCAL;
#endif
#if defined(PNG_READ_pHYs_SUPPORTED)
PNG_pHYs;
#endif
#if defined(PNG_READ_sBIT_SUPPORTED)
PNG_sBIT;
#endif
#if defined(PNG_READ_sCAL_SUPPORTED)
PNG_sCAL;
#endif
#if defined(PNG_READ_sPLT_SUPPORTED)
PNG_sPLT;
#endif
#if defined(PNG_READ_sRGB_SUPPORTED)
PNG_sRGB;
#endif
#if defined(PNG_READ_tEXt_SUPPORTED)
PNG_tEXt;
#endif
#if defined(PNG_READ_tIME_SUPPORTED)
PNG_tIME;
#endif
#if defined(PNG_READ_tRNS_SUPPORTED)
PNG_tRNS;
#endif
#if defined(PNG_READ_zTXt_SUPPORTED)
PNG_zTXt;
#endif
#endif /* PNG_USE_LOCAL_ARRAYS */
png_read_data(png_ptr, chunk_length, 4);
length = png_get_uint_31(png_ptr,chunk_length);
png_reset_crc(png_ptr);
png_crc_read(png_ptr, png_ptr->chunk_name, 4);
png_debug1(0, "Reading %s chunk.\n", png_ptr->chunk_name);
if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4))
png_handle_IHDR(png_ptr, info_ptr, length);
else if (!png_memcmp(png_ptr->chunk_name, png_IEND, 4))
png_handle_IEND(png_ptr, info_ptr, length);
#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
else if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name))
{
if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
{
if (length > 0 || png_ptr->mode & PNG_AFTER_IDAT)
png_error(png_ptr, "Too many IDAT's found");
}
else
png_ptr->mode |= PNG_AFTER_IDAT;
png_handle_unknown(png_ptr, info_ptr, length);
if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
png_ptr->mode |= PNG_HAVE_PLTE;
}
#endif
else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
{
/* Zero length IDATs are legal after the last IDAT has been
* read, but not after other chunks have been read.
*/
if (length > 0 || png_ptr->mode & PNG_AFTER_IDAT)
png_error(png_ptr, "Too many IDAT's found");
png_crc_finish(png_ptr, length);
}
else if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
png_handle_PLTE(png_ptr, info_ptr, length);
#if defined(PNG_READ_bKGD_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_bKGD, 4))
png_handle_bKGD(png_ptr, info_ptr, length);
#endif
#if defined(PNG_READ_cHRM_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_cHRM, 4))
png_handle_cHRM(png_ptr, info_ptr, length);
#endif
#if defined(PNG_READ_gAMA_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_gAMA, 4))
png_handle_gAMA(png_ptr, info_ptr, length);
#endif
#if defined(PNG_READ_hIST_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_hIST, 4))
png_handle_hIST(png_ptr, info_ptr, length);
#endif
#if defined(PNG_READ_oFFs_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_oFFs, 4))
png_handle_oFFs(png_ptr, info_ptr, length);
#endif
#if defined(PNG_READ_pCAL_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_pCAL, 4))
png_handle_pCAL(png_ptr, info_ptr, length);
#endif
#if defined(PNG_READ_sCAL_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_sCAL, 4))
png_handle_sCAL(png_ptr, info_ptr, length);
#endif
#if defined(PNG_READ_pHYs_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_pHYs, 4))
png_handle_pHYs(png_ptr, info_ptr, length);
#endif
#if defined(PNG_READ_sBIT_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_sBIT, 4))
png_handle_sBIT(png_ptr, info_ptr, length);
#endif
#if defined(PNG_READ_sRGB_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4))
png_handle_sRGB(png_ptr, info_ptr, length);
#endif
#if defined(PNG_READ_iCCP_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_iCCP, 4))
png_handle_iCCP(png_ptr, info_ptr, length);
#endif
#if defined(PNG_READ_sPLT_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_sPLT, 4))
png_handle_sPLT(png_ptr, info_ptr, length);
#endif
#if defined(PNG_READ_tEXt_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4))
png_handle_tEXt(png_ptr, info_ptr, length);
#endif
#if defined(PNG_READ_tIME_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_tIME, 4))
png_handle_tIME(png_ptr, info_ptr, length);
#endif
#if defined(PNG_READ_tRNS_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_tRNS, 4))
png_handle_tRNS(png_ptr, info_ptr, length);
#endif
#if defined(PNG_READ_zTXt_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_zTXt, 4))
png_handle_zTXt(png_ptr, info_ptr, length);
#endif
#if defined(PNG_READ_iTXt_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_iTXt, 4))
png_handle_iTXt(png_ptr, info_ptr, length);
#endif
else
png_handle_unknown(png_ptr, info_ptr, length);
} while (!(png_ptr->mode & PNG_HAVE_IEND));
}
/* Writes all the PNG information. This is the suggested way to use the
* library. If you have a new chunk to add, make a function to write it,
* and put it in the correct location here. If you want the chunk written
* after the image data, put it in png_write_end(). I strongly encourage
* you to supply a PNG_INFO_ flag, and check info_ptr->valid before writing
* the chunk, as that will keep the code from breaking if you want to just
* write a plain PNG file. If you have long comments, I suggest writing
* them in png_write_end(), and compressing them.
*/
void PNGAPI
png_write_info_before_PLTE(png_structp png_ptr, png_infop info_ptr)
{
png_debug(1, "in png_write_info_before_PLTE\n");
if (png_ptr == NULL || info_ptr == NULL)
return;
if (!(png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE))
{
png_write_sig(png_ptr); /* write PNG signature */
#if defined(PNG_MNG_FEATURES_SUPPORTED)
if((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE)&&(png_ptr->mng_features_permitted))
{
png_warning(png_ptr,"MNG features are not allowed in a PNG datastream");
png_ptr->mng_features_permitted=0;
}
#endif
/* write IHDR information. */
png_write_IHDR(png_ptr, info_ptr->width, info_ptr->height,
info_ptr->bit_depth, info_ptr->color_type, info_ptr->compression_type,
info_ptr->filter_type,
#if defined(PNG_WRITE_INTERLACING_SUPPORTED)
info_ptr->interlace_type);
#else
0);
#endif
/* the rest of these check to see if the valid field has the appropriate
flag set, and if it does, writes the chunk. */
#if defined(PNG_WRITE_gAMA_SUPPORTED)
if (info_ptr->valid & PNG_INFO_gAMA)
{
# ifdef PNG_FLOATING_POINT_SUPPORTED
png_write_gAMA(png_ptr, info_ptr->gamma);
#else
#ifdef PNG_FIXED_POINT_SUPPORTED
png_write_gAMA_fixed(png_ptr, info_ptr->int_gamma);
# endif
#endif
}
#endif
#if defined(PNG_WRITE_sRGB_SUPPORTED)
if (info_ptr->valid & PNG_INFO_sRGB)
png_write_sRGB(png_ptr, (int)info_ptr->srgb_intent);
#endif
#if defined(PNG_WRITE_iCCP_SUPPORTED)
if (info_ptr->valid & PNG_INFO_iCCP)
png_write_iCCP(png_ptr, info_ptr->iccp_name, PNG_COMPRESSION_TYPE_BASE,
info_ptr->iccp_profile, (int)info_ptr->iccp_proflen);
#endif
#if defined(PNG_WRITE_sBIT_SUPPORTED)
if (info_ptr->valid & PNG_INFO_sBIT)
png_write_sBIT(png_ptr, &(info_ptr->sig_bit), info_ptr->color_type);
#endif
#if defined(PNG_WRITE_cHRM_SUPPORTED)
if (info_ptr->valid & PNG_INFO_cHRM)
{
#ifdef PNG_FLOATING_POINT_SUPPORTED
png_write_cHRM(png_ptr,
info_ptr->x_white, info_ptr->y_white,
info_ptr->x_red, info_ptr->y_red,
info_ptr->x_green, info_ptr->y_green,
info_ptr->x_blue, info_ptr->y_blue);
#else
# ifdef PNG_FIXED_POINT_SUPPORTED
png_write_cHRM_fixed(png_ptr,
info_ptr->int_x_white, info_ptr->int_y_white,
info_ptr->int_x_red, info_ptr->int_y_red,
info_ptr->int_x_green, info_ptr->int_y_green,
info_ptr->int_x_blue, info_ptr->int_y_blue);
# endif
#endif
}
#endif
#if defined(PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED)
if (info_ptr->unknown_chunks_num)
{
png_unknown_chunk *up;
png_debug(5, "writing extra chunks\n");
for (up = info_ptr->unknown_chunks;
up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
up++)
{
int keep=png_handle_as_unknown(png_ptr, up->name);
if (keep != PNG_HANDLE_CHUNK_NEVER &&
up->location && !(up->location & PNG_HAVE_PLTE) &&
!(up->location & PNG_HAVE_IDAT) &&
((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
(png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
{
png_write_chunk(png_ptr, up->name, up->data, up->size);
}
}
}
#endif
png_ptr->mode |= PNG_WROTE_INFO_BEFORE_PLTE;
}
/* Writes the end of the PNG file. If you don't want to write comments or
* time information, you can pass NULL for info. If you already wrote these
* in png_write_info(), do not write them again here. If you have long
* comments, I suggest writing them here, and compressing them.
*/
void PNGAPI
png_write_end(png_structp png_ptr, png_infop info_ptr)
{
png_debug(1, "in png_write_end");
if (png_ptr == NULL)
return;
if (!(png_ptr->mode & PNG_HAVE_IDAT))
png_error(png_ptr, "No IDATs written into file");
#ifdef PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED
if (png_ptr->num_palette_max > png_ptr->num_palette)
png_benign_error(png_ptr, "Wrote palette index exceeding num_palette");
#endif
/* See if user wants us to write information chunks */
if (info_ptr != NULL)
{
#ifdef PNG_WRITE_TEXT_SUPPORTED
int i; /* local index variable */
#endif
#ifdef PNG_WRITE_tIME_SUPPORTED
/* Check to see if user has supplied a time chunk */
if ((info_ptr->valid & PNG_INFO_tIME) &&
!(png_ptr->mode & PNG_WROTE_tIME))
png_write_tIME(png_ptr, &(info_ptr->mod_time));
#endif
#ifdef PNG_WRITE_TEXT_SUPPORTED
/* Loop through comment chunks */
for (i = 0; i < info_ptr->num_text; i++)
{
png_debug2(2, "Writing trailer text chunk %d, type %d", i,
info_ptr->text[i].compression);
/* An internationalized chunk? */
if (info_ptr->text[i].compression > 0)
{
#ifdef PNG_WRITE_iTXt_SUPPORTED
/* Write international chunk */
png_write_iTXt(png_ptr,
info_ptr->text[i].compression,
info_ptr->text[i].key,
info_ptr->text[i].lang,
info_ptr->text[i].lang_key,
info_ptr->text[i].text);
/* Mark this chunk as written */
info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
#else
png_warning(png_ptr, "Unable to write international text");
#endif
}
else if (info_ptr->text[i].compression >= PNG_TEXT_COMPRESSION_zTXt)
{
#ifdef PNG_WRITE_zTXt_SUPPORTED
/* Write compressed chunk */
png_write_zTXt(png_ptr, info_ptr->text[i].key,
info_ptr->text[i].text, 0,
info_ptr->text[i].compression);
/* Mark this chunk as written */
info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
#else
png_warning(png_ptr, "Unable to write compressed text");
#endif
}
else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
{
#ifdef PNG_WRITE_tEXt_SUPPORTED
/* Write uncompressed chunk */
png_write_tEXt(png_ptr, info_ptr->text[i].key,
info_ptr->text[i].text, 0);
/* Mark this chunk as written */
info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
#else
png_warning(png_ptr, "Unable to write uncompressed text");
#endif
}
}
#endif
#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
if (info_ptr->unknown_chunks_num)
{
png_unknown_chunk *up;
png_debug(5, "writing extra chunks");
for (up = info_ptr->unknown_chunks;
up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
up++)
{
int keep = png_handle_as_unknown(png_ptr, up->name);
if (keep != PNG_HANDLE_CHUNK_NEVER &&
up->location &&
(up->location & PNG_AFTER_IDAT) &&
((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
(png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
{
png_write_chunk(png_ptr, up->name, up->data, up->size);
}
}
}
#endif
}
png_ptr->mode |= PNG_AFTER_IDAT;
/* Write end of PNG file */
png_write_IEND(png_ptr);
/* This flush, added in libpng-1.0.8, removed from libpng-1.0.9beta03,
* and restored again in libpng-1.2.30, may cause some applications that
* do not set png_ptr->output_flush_fn to crash. If your application
* experiences a problem, please try building libpng with
* PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED defined, and report the event to
* png-mng-implement at lists.sf.net .
*/
#ifdef PNG_WRITE_FLUSH_SUPPORTED
# ifdef PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED
png_flush(png_ptr);
# endif
#endif
}
void PNGAPI
png_write_info(png_structp png_ptr, png_infop info_ptr)
{
#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
int i;
#endif
png_debug(1, "in png_write_info");
if (png_ptr == NULL || info_ptr == NULL)
return;
png_write_info_before_PLTE(png_ptr, info_ptr);
if (info_ptr->valid & PNG_INFO_PLTE)
png_write_PLTE(png_ptr, info_ptr->palette,
(png_uint_32)info_ptr->num_palette);
else if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
png_error(png_ptr, "Valid palette required for paletted images");
#ifdef PNG_WRITE_tRNS_SUPPORTED
if (info_ptr->valid & PNG_INFO_tRNS)
{
#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
/* Invert the alpha channel (in tRNS) */
if ((png_ptr->transformations & PNG_INVERT_ALPHA) &&
info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
{
int j;
for (j = 0; j<(int)info_ptr->num_trans; j++)
info_ptr->trans_alpha[j] =
(png_byte)(255 - info_ptr->trans_alpha[j]);
}
#endif
png_write_tRNS(png_ptr, info_ptr->trans_alpha, &(info_ptr->trans_color),
info_ptr->num_trans, info_ptr->color_type);
}
#endif
#ifdef PNG_WRITE_bKGD_SUPPORTED
if (info_ptr->valid & PNG_INFO_bKGD)
png_write_bKGD(png_ptr, &(info_ptr->background), info_ptr->color_type);
#endif
#ifdef PNG_WRITE_hIST_SUPPORTED
if (info_ptr->valid & PNG_INFO_hIST)
png_write_hIST(png_ptr, info_ptr->hist, info_ptr->num_palette);
#endif
#ifdef PNG_WRITE_oFFs_SUPPORTED
if (info_ptr->valid & PNG_INFO_oFFs)
png_write_oFFs(png_ptr, info_ptr->x_offset, info_ptr->y_offset,
info_ptr->offset_unit_type);
#endif
#ifdef PNG_WRITE_pCAL_SUPPORTED
if (info_ptr->valid & PNG_INFO_pCAL)
png_write_pCAL(png_ptr, info_ptr->pcal_purpose, info_ptr->pcal_X0,
info_ptr->pcal_X1, info_ptr->pcal_type, info_ptr->pcal_nparams,
info_ptr->pcal_units, info_ptr->pcal_params);
#endif
#ifdef PNG_WRITE_sCAL_SUPPORTED
if (info_ptr->valid & PNG_INFO_sCAL)
png_write_sCAL_s(png_ptr, (int)info_ptr->scal_unit,
info_ptr->scal_s_width, info_ptr->scal_s_height);
#endif /* sCAL */
#ifdef PNG_WRITE_pHYs_SUPPORTED
if (info_ptr->valid & PNG_INFO_pHYs)
png_write_pHYs(png_ptr, info_ptr->x_pixels_per_unit,
info_ptr->y_pixels_per_unit, info_ptr->phys_unit_type);
#endif /* pHYs */
#ifdef PNG_WRITE_tIME_SUPPORTED
if (info_ptr->valid & PNG_INFO_tIME)
{
png_write_tIME(png_ptr, &(info_ptr->mod_time));
png_ptr->mode |= PNG_WROTE_tIME;
}
#endif /* tIME */
#ifdef PNG_WRITE_sPLT_SUPPORTED
if (info_ptr->valid & PNG_INFO_sPLT)
for (i = 0; i < (int)info_ptr->splt_palettes_num; i++)
png_write_sPLT(png_ptr, info_ptr->splt_palettes + i);
#endif /* sPLT */
#ifdef PNG_WRITE_TEXT_SUPPORTED
/* Check to see if we need to write text chunks */
for (i = 0; i < info_ptr->num_text; i++)
{
png_debug2(2, "Writing header text chunk %d, type %d", i,
info_ptr->text[i].compression);
/* An internationalized chunk? */
if (info_ptr->text[i].compression > 0)
{
#ifdef PNG_WRITE_iTXt_SUPPORTED
/* Write international chunk */
png_write_iTXt(png_ptr,
info_ptr->text[i].compression,
info_ptr->text[i].key,
info_ptr->text[i].lang,
info_ptr->text[i].lang_key,
info_ptr->text[i].text);
/* Mark this chunk as written */
if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
else
info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
#else
png_warning(png_ptr, "Unable to write international text");
#endif
}
/* If we want a compressed text chunk */
else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_zTXt)
{
#ifdef PNG_WRITE_zTXt_SUPPORTED
/* Write compressed chunk */
png_write_zTXt(png_ptr, info_ptr->text[i].key,
info_ptr->text[i].text, 0,
info_ptr->text[i].compression);
/* Mark this chunk as written */
info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
#else
png_warning(png_ptr, "Unable to write compressed text");
#endif
}
else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
{
#ifdef PNG_WRITE_tEXt_SUPPORTED
/* Write uncompressed chunk */
png_write_tEXt(png_ptr, info_ptr->text[i].key,
info_ptr->text[i].text,
0);
/* Mark this chunk as written */
info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
#else
/* Can't get here */
png_warning(png_ptr, "Unable to write uncompressed text");
#endif
}
}
#endif /* tEXt */
#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
if (info_ptr->unknown_chunks_num)
{
png_unknown_chunk *up;
png_debug(5, "writing extra chunks");
for (up = info_ptr->unknown_chunks;
up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
up++)
{
int keep = png_handle_as_unknown(png_ptr, up->name);
if (keep != PNG_HANDLE_CHUNK_NEVER &&
up->location &&
(up->location & PNG_HAVE_PLTE) &&
!(up->location & PNG_HAVE_IDAT) &&
!(up->location & PNG_AFTER_IDAT) &&
((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
(png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
{
png_write_chunk(png_ptr, up->name, up->data, up->size);
}
}
}
#endif
}
