/* 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.
*/
bool PNGAPI png_read_info(png_structp png_ptr, png_infop info_ptr){
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;
if(!png_read_data(png_ptr, &(info_ptr->signature[num_checked]), num_to_check))
return false;
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))
return false;//png_error(png_ptr, "Not a PNG file");
else
return false;//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
static PNG_IHDR;
static PNG_IDAT;
static PNG_IEND;
static PNG_PLTE;
#if defined(PNG_READ_bKGD_SUPPORTED)
static PNG_bKGD;
#endif
#if defined(PNG_READ_cHRM_SUPPORTED)
static PNG_cHRM;
#endif
#if defined(PNG_READ_gAMA_SUPPORTED)
static PNG_gAMA;
#endif
#if defined(PNG_READ_hIST_SUPPORTED)
static PNG_hIST;
#endif
#if defined(PNG_READ_iCCP_SUPPORTED)
static PNG_iCCP;
#endif
#if defined(PNG_READ_iTXt_SUPPORTED)
static PNG_iTXt;
#endif
#if defined(PNG_READ_oFFs_SUPPORTED)
static PNG_oFFs;
#endif
#if defined(PNG_READ_pCAL_SUPPORTED)
static PNG_pCAL;
#endif
#if defined(PNG_READ_pHYs_SUPPORTED)
static PNG_pHYs;
#endif
#if defined(PNG_READ_sBIT_SUPPORTED)
static PNG_sBIT;
#endif
#if defined(PNG_READ_sCAL_SUPPORTED)
static PNG_sCAL;
#endif
#if defined(PNG_READ_sPLT_SUPPORTED)
static PNG_sPLT;
#endif
#if defined(PNG_READ_sRGB_SUPPORTED)
static PNG_sRGB;
#endif
#if defined(PNG_READ_tEXt_SUPPORTED)
static PNG_tEXt;
#endif
#if defined(PNG_READ_tIME_SUPPORTED)
static PNG_tIME;
#endif
#if defined(PNG_READ_tRNS_SUPPORTED)
static PNG_tRNS;
#endif
#if defined(PNG_READ_zTXt_SUPPORTED)
static PNG_zTXt;
#endif
#endif /* PNG_GLOBAL_ARRAYS */
png_byte chunk_length[4];
png_uint_32 length;
if(!png_read_data(png_ptr, chunk_length, 4))
return false;
length = png_get_uint_32(chunk_length);
png_reset_crc(png_ptr);
if(!png_crc_read(png_ptr, png_ptr->chunk_name, 4))
return false;
png_debug2(0, "Reading %s chunk, length=%lu.\n", png_ptr->chunk_name,
length);
if (length > PNG_MAX_UINT)
return false;//png_error(png_ptr, "Invalid chunk 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_IHDR, 4)){
if(!png_handle_IHDR(png_ptr, info_ptr, length))
return false;
}
else if (!png_memcmp(png_ptr->chunk_name, png_IEND, 4)){
if(!png_handle_IEND(png_ptr, info_ptr, length))
return false;
}
#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;
if(!png_handle_unknown(png_ptr, info_ptr, length))
return false;
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))
return false;//png_error(png_ptr, "Missing IHDR before IDAT");
else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
!(png_ptr->mode & PNG_HAVE_PLTE))
return false;//png_error(png_ptr, "Missing PLTE before IDAT");
break;
}
}
#endif
else if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4)){
if(!png_handle_PLTE(png_ptr, info_ptr, length))
return false;
}else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
{
if (!(png_ptr->mode & PNG_HAVE_IHDR))
return false;//png_error(png_ptr, "Missing IHDR before IDAT");
else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
!(png_ptr->mode & PNG_HAVE_PLTE))
return false;//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)){
if(!png_handle_sBIT(png_ptr, info_ptr, length))
return false;
}
#endif
#if defined(PNG_READ_sRGB_SUPPORTED)
else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4)){
if(!png_handle_sRGB(png_ptr, info_ptr, length))
return false;
}
#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{
if(!png_handle_unknown(png_ptr, info_ptr, length))
return false;
}
}
return true;
}
/*
* @brief Get info about the apng
* @note Also validates the apng & sets it up to have frames read
*
* @retval PNG_ERROR_NONE (0), otherwise will raise exception
*/
int apng_ani::load_header()
{
char filename[MAX_FILENAME_LEN];
strcpy_s(filename, _filename.c_str());
char *p = strchr( filename, '.' );
if ( p != nullptr ) *p = 0;
strcat_s( filename, ".png" );
_cfp = cfopen( filename , "rb" );
if ( _cfp == nullptr) {
_apng_failed("couldn't open filename");
}
_reading = true;
ubyte sig[8];
if (cfread(sig, 8, 1, _cfp) != 1) {
_apng_failed("cfread of png signature failed");
}
if (png_sig_cmp(sig, 0, 8) != 0) {
_apng_failed("file has invalid png signature");
}
// setup chunk sizes before use
_chunk_IHDR.data.resize(25); // fixed IHDR chunk size
_chunk.data.resize(25); // match the other sizes, maybe waste up to 13 bytes (ooooh)
_id = _read_chunk(_chunk_IHDR);
if (_id != id_IHDR || _chunk_IHDR.size != 25) {
_apng_failed("failed to read IHDR chunk");
}
w = png_get_uint_32(&_chunk_IHDR.data[8]);
h = png_get_uint_32(&_chunk_IHDR.data[12]);
_row_len = w * 4;
// setup frames & keep bm_create happy
_image_size = _row_len * h;
frame.data.reserve(_image_size); // alloc only once
frame.data.assign(_image_size, 0); // all transparent black per spec
frame.rows.resize(h);
_frame_raw.data.resize(_image_size);
_frame_raw.rows.resize(h);
_frame_next.data.resize(_image_size);
_frame_next.rows.resize(h);
for (uint i = 0; i < h; ++i) {
// everything is correctly sized above; avoid .at() error checks
frame.rows[i] = &frame.data[i * _row_len];
_frame_raw.rows[i] = &_frame_raw.data[i * _row_len];
_frame_next.rows[i] = &_frame_next.data[i * _row_len];
}
// read all data
while (!cfeof(_cfp)) {
_process_chunk();
}
// should be at EOF; attach to _frame_offsets to make next_frame code simpler
Assertion(cfeof(_cfp) != 0, "apng not at EOF, get a coder!");
_frame_offsets.push_back(cftell(_cfp));
// sanity checks
if (anim_time <= 0.0f) {
_apng_failed("animation duration <= 0.0f, bad data?");
}
if (nframes < 1) {
_apng_failed("animation didn't have any frames, is this a static png?");
}
// back to start, including reset of _cfp so it can be used for the 1st frame
_reading = false;
if (cfseek(_cfp, _frame_offsets.at(0), CF_SEEK_SET) != 0) {
_apng_failed("couldn't seek to 1st fcTL offset");
}
return PNG_ERROR_NONE;
}
void
nsPNGDecoder::WriteInternal(const char *aBuffer, uint32_t aCount)
{
// We use gotos, so we need to declare variables here
uint32_t width = 0;
uint32_t height = 0;
NS_ABORT_IF_FALSE(!HasError(), "Shouldn't call WriteInternal after error!");
// If we only want width/height, we don't need to go through libpng
if (IsSizeDecode()) {
// Are we done?
if (mHeaderBytesRead == BYTES_NEEDED_FOR_DIMENSIONS)
return;
// Read data into our header buffer
uint32_t bytesToRead = NS_MIN(aCount, BYTES_NEEDED_FOR_DIMENSIONS -
mHeaderBytesRead);
memcpy(mHeaderBuf + mHeaderBytesRead, aBuffer, bytesToRead);
mHeaderBytesRead += bytesToRead;
// If we're done now, verify the data and set up the container
if (mHeaderBytesRead == BYTES_NEEDED_FOR_DIMENSIONS) {
// Check that the signature bytes are right
if (memcmp(mHeaderBuf, nsPNGDecoder::pngSignatureBytes,
sizeof(pngSignatureBytes))) {
PostDataError();
return;
}
// Grab the width and height, accounting for endianness (thanks libpng!)
width = png_get_uint_32(mHeaderBuf + WIDTH_OFFSET);
height = png_get_uint_32(mHeaderBuf + HEIGHT_OFFSET);
// Too big?
if ((width > MOZ_PNG_MAX_DIMENSION) || (height > MOZ_PNG_MAX_DIMENSION)) {
PostDataError();
return;
}
// Post our size to the superclass
PostSize(width, height);
}
}
// Otherwise, we're doing a standard decode
else {
// libpng uses setjmp/longjmp for error handling - set the buffer
if (setjmp(png_jmpbuf(mPNG))) {
// We might not really know what caused the error, but it makes more
// sense to blame the data.
if (!HasError())
PostDataError();
png_destroy_read_struct(&mPNG, &mInfo, NULL);
return;
}
// Pass the data off to libpng
png_process_data(mPNG, mInfo, (unsigned char *)aBuffer, aCount);
}
}
void
nsPNGDecoder::WriteInternal(const char *aBuffer, uint32_t aCount, DecodeStrategy)
{
NS_ABORT_IF_FALSE(!HasError(), "Shouldn't call WriteInternal after error!");
// If we only want width/height, we don't need to go through libpng
if (IsSizeDecode()) {
// Are we done?
if (mHeaderBytesRead == BYTES_NEEDED_FOR_DIMENSIONS)
return;
// Scan the header for the width and height bytes
uint32_t pos = 0;
const uint8_t *bptr = (uint8_t *)aBuffer;
while (pos < aCount && mHeaderBytesRead < BYTES_NEEDED_FOR_DIMENSIONS) {
// Verify the signature bytes
if (mHeaderBytesRead < sizeof(pngSignatureBytes)) {
if (bptr[pos] != nsPNGDecoder::pngSignatureBytes[mHeaderBytesRead]) {
PostDataError();
return;
}
}
// Get width and height bytes into the buffer
if ((mHeaderBytesRead >= WIDTH_OFFSET) &&
(mHeaderBytesRead < BYTES_NEEDED_FOR_DIMENSIONS)) {
mSizeBytes[mHeaderBytesRead - WIDTH_OFFSET] = bptr[pos];
}
pos ++;
mHeaderBytesRead ++;
}
// If we're done now, verify the data and set up the container
if (mHeaderBytesRead == BYTES_NEEDED_FOR_DIMENSIONS) {
// Grab the width and height, accounting for endianness (thanks libpng!)
uint32_t width = png_get_uint_32(mSizeBytes);
uint32_t height = png_get_uint_32(mSizeBytes + 4);
// Too big?
if ((width > MOZ_PNG_MAX_DIMENSION) || (height > MOZ_PNG_MAX_DIMENSION)) {
PostDataError();
return;
}
// Post our size to the superclass
PostSize(width, height);
}
}
// Otherwise, we're doing a standard decode
else {
// libpng uses setjmp/longjmp for error handling - set the buffer
if (setjmp(png_jmpbuf(mPNG))) {
// We might not really know what caused the error, but it makes more
// sense to blame the data.
if (!HasError())
PostDataError();
png_destroy_read_struct(&mPNG, &mInfo, nullptr);
return;
}
// Pass the data off to libpng
png_process_data(mPNG, mInfo, (unsigned char *)aBuffer, aCount);
}
}
/*
* @brief manually process a single chunk of apng data
*/
void apng_ani::_process_chunk()
{
_id = _read_chunk(_chunk);
if (_id == id_acTL && !_got_IDAT && !_got_acTL) {
// animation control chunk
if (!_reading) {
return;
}
nframes = png_get_uint_32(&_chunk.data[8]);
plays = png_get_uint_32(&_chunk.data[12]);
if (!nframes || nframes > PNG_UINT_31_MAX || plays > PNG_UINT_31_MAX) {
_apng_failed("invalid apng acTL data");
}
_got_acTL = true;
_frames.reserve(nframes);
_frame_offsets.reserve(nframes+1); // extra 1 is for EOF offset
}
else if (_id == id_fcTL && (!_got_IDAT || _got_acTL)) {
// frame control chunk
if (_reading) {
uint sequence_num = png_get_uint_32(&_chunk.data[8]);
if (sequence_num != _sequence_num++) {
_apng_failed("invalid apng fcTL sequence number");
}
}
// handle frame finish in next_frame
_framew = png_get_uint_32(&_chunk.data[12]);
_frameh = png_get_uint_32(&_chunk.data[16]);
_x_offset = png_get_uint_32(&_chunk.data[20]);
_y_offset = png_get_uint_32(&_chunk.data[24]);
_delay_num = png_get_uint_16(&_chunk.data[28]);
_delay_den = png_get_uint_16(&_chunk.data[30]);
_dispose_op = _chunk.data[32];
_blend_op = _chunk.data[33];
if (_reading &&
(_framew > cMaxPNGSize || _frameh > cMaxPNGSize
|| _x_offset > cMaxPNGSize || _y_offset > cMaxPNGSize
|| _x_offset + _framew > w || _y_offset + _frameh > h
|| _dispose_op > 2 || _blend_op > 1)) {
_apng_failed("invalid apng fcTL data");
}
// according to spec...
if (current_frame == 0 && _dispose_op == 2) {
_dispose_op = 1;
}
if (_delay_den == 0) _delay_den = 100; // APNG spec
if (_delay_num == 0) _delay_num = 1; // arbitrary lower bound
float frame_delay = static_cast<float>(_delay_num)/static_cast<float>(_delay_den);
frame.delay = frame_delay;
if (_reading) {
anim_time+= frame_delay;
_frame_offsets.push_back((int)_offset);
}
else {
if (_got_IDAT && _processing_start()) {
_apng_failed("couldn't start fdat apng frame");
}
}
}
else if (_id == id_IDAT) {
_got_IDAT = true;
_processing_data(&_chunk.data[0], _chunk.size);
}
else if (_id == id_fdAT && _got_acTL) {
if (_reading) {
uint sequence_num = png_get_uint_32(&_chunk.data[8]);
if (sequence_num != _sequence_num++) {
_apng_failed("invalid apng fdAT sequence number");
}
}
if (_reading) {
return;
}
png_save_uint_32(&_chunk.data[4], _chunk.size - 16);
memcpy(&_chunk.data[8], "IDAT", 4);
_processing_data(&_chunk.data[4], _chunk.size - 4);
}
else if (_id == id_IEND) {
return;
}
else if (not_chunk(_chunk.data[4]) || not_chunk(_chunk.data[5]) ||
not_chunk(_chunk.data[6]) || not_chunk(_chunk.data[7])) {
_apng_failed("unknown chunk ID found");
}
else if (!_got_IDAT) {
_processing_data(&_chunk.data[0], _chunk.size);
_info_chunks.push_back(_chunk);
}
}
void /* PRIVATE */
png_push_read_IDAT(png_structp png_ptr)
{
#ifdef PNG_USE_LOCAL_ARRAYS
PNG_IDAT;
#endif
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_32(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_bytep)png_IDAT, 4))
{
png_ptr->process_mode = PNG_READ_CHUNK_MODE;
if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
png_error(png_ptr, "Not enough compressed data");
return;
}
png_ptr->idat_size = png_ptr->push_length;
}
if (png_ptr->idat_size && png_ptr->save_buffer_size)
{
png_size_t save_size;
if (png_ptr->idat_size < (png_uint_32)png_ptr->save_buffer_size)
{
save_size = (png_size_t)png_ptr->idat_size;
/* check for overflow */
if((png_uint_32)save_size != png_ptr->idat_size)
png_error(png_ptr, "save_size overflowed in pngpread");
}
else
save_size = png_ptr->save_buffer_size;
png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size);
if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
png_process_IDAT_data(png_ptr, png_ptr->save_buffer_ptr, save_size);
png_ptr->idat_size -= save_size;
png_ptr->buffer_size -= save_size;
png_ptr->save_buffer_size -= save_size;
png_ptr->save_buffer_ptr += save_size;
}
if (png_ptr->idat_size && png_ptr->current_buffer_size)
{
png_size_t save_size;
if (png_ptr->idat_size < (png_uint_32)png_ptr->current_buffer_size)
{
save_size = (png_size_t)png_ptr->idat_size;
/* check for overflow */
if((png_uint_32)save_size != png_ptr->idat_size)
png_error(png_ptr, "save_size overflowed in pngpread");
}
else
save_size = png_ptr->current_buffer_size;
png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size);
if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
png_process_IDAT_data(png_ptr, png_ptr->current_buffer_ptr, save_size);
png_ptr->idat_size -= save_size;
png_ptr->buffer_size -= save_size;
png_ptr->current_buffer_size -= save_size;
png_ptr->current_buffer_ptr += save_size;
}
if (!png_ptr->idat_size)
{
if (png_ptr->buffer_size < 4)
{
png_push_save_buffer(png_ptr);
return;
}
png_crc_finish(png_ptr, 0);
png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
png_ptr->mode |= PNG_AFTER_IDAT;
}
}
void /* PRIVATE */
png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
{
#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_sRGB_SUPPORTED)
PNG_sRGB;
#endif
#if defined(PNG_READ_sPLT_SUPPORTED)
PNG_sPLT;
#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 */
/* 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_32(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_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_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_bytep)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->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;
}
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);
}
#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 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");
/* save jump buffer and error functions */
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_GLOBAL_ARRAYS */
png_read_data(png_ptr, chunk_length, 4);
length = png_get_uint_32(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));
}
void PNGAPI
png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
{
#ifdef PNG_USE_LOCAL_ARRAYS
PNG_IDAT;
const int png_pass_dsp_mask[7] = {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff};
const int png_pass_mask[7] = {0x80, 0x08, 0x88, 0x22, 0xaa, 0x55, 0xff};
#endif
int ret;
png_debug2(1, "in png_read_row (row %lu, pass %d)\n",
png_ptr->row_number, png_ptr->pass);
/* save jump buffer and error functions */
if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
png_read_start_row(png_ptr);
if (png_ptr->row_number == 0 && png_ptr->pass == 0)
{
/* check for transforms that have been set but were defined out */
#if defined(PNG_WRITE_INVERT_SUPPORTED) && !defined(PNG_READ_INVERT_SUPPORTED)
if (png_ptr->transformations & PNG_INVERT_MONO)
png_warning(png_ptr, "PNG_READ_INVERT_SUPPORTED is not defined.");
#endif
#if defined(PNG_WRITE_FILLER_SUPPORTED) && !defined(PNG_READ_FILLER_SUPPORTED)
if (png_ptr->transformations & PNG_FILLER)
png_warning(png_ptr, "PNG_READ_FILLER_SUPPORTED is not defined.");
#endif
#if defined(PNG_WRITE_PACKSWAP_SUPPORTED) && !defined(PNG_READ_PACKSWAP_SUPPORTED)
if (png_ptr->transformations & PNG_PACKSWAP)
png_warning(png_ptr, "PNG_READ_PACKSWAP_SUPPORTED is not defined.");
#endif
#if defined(PNG_WRITE_PACK_SUPPORTED) && !defined(PNG_READ_PACK_SUPPORTED)
if (png_ptr->transformations & PNG_PACK)
png_warning(png_ptr, "PNG_READ_PACK_SUPPORTED is not defined.");
#endif
#if defined(PNG_WRITE_SHIFT_SUPPORTED) && !defined(PNG_READ_SHIFT_SUPPORTED)
if (png_ptr->transformations & PNG_SHIFT)
png_warning(png_ptr, "PNG_READ_SHIFT_SUPPORTED is not defined.");
#endif
#if defined(PNG_WRITE_BGR_SUPPORTED) && !defined(PNG_READ_BGR_SUPPORTED)
if (png_ptr->transformations & PNG_BGR)
png_warning(png_ptr, "PNG_READ_BGR_SUPPORTED is not defined.");
#endif
#if defined(PNG_WRITE_SWAP_SUPPORTED) && !defined(PNG_READ_SWAP_SUPPORTED)
if (png_ptr->transformations & PNG_SWAP_BYTES)
png_warning(png_ptr, "PNG_READ_SWAP_SUPPORTED is not defined.");
#endif
}
#if defined(PNG_READ_INTERLACING_SUPPORTED)
/* if interlaced and we do not need a new row, combine row and return */
if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
{
switch (png_ptr->pass)
{
case 0:
if (png_ptr->row_number & 0x07)
{
if (dsp_row != NULL)
png_combine_row(png_ptr, dsp_row,
png_pass_dsp_mask[png_ptr->pass]);
png_read_finish_row(png_ptr);
return;
}
break;
case 1:
if ((png_ptr->row_number & 0x07) || png_ptr->width < 5)
{
if (dsp_row != NULL)
png_combine_row(png_ptr, dsp_row,
png_pass_dsp_mask[png_ptr->pass]);
png_read_finish_row(png_ptr);
return;
}
break;
case 2:
if ((png_ptr->row_number & 0x07) != 4)
{
if (dsp_row != NULL && (png_ptr->row_number & 4))
png_combine_row(png_ptr, dsp_row,
png_pass_dsp_mask[png_ptr->pass]);
png_read_finish_row(png_ptr);
return;
}
break;
case 3:
if ((png_ptr->row_number & 3) || png_ptr->width < 3)
{
if (dsp_row != NULL)
png_combine_row(png_ptr, dsp_row,
png_pass_dsp_mask[png_ptr->pass]);
png_read_finish_row(png_ptr);
return;
}
break;
case 4:
if ((png_ptr->row_number & 3) != 2)
{
if (dsp_row != NULL && (png_ptr->row_number & 2))
png_combine_row(png_ptr, dsp_row,
png_pass_dsp_mask[png_ptr->pass]);
png_read_finish_row(png_ptr);
return;
}
break;
case 5:
if ((png_ptr->row_number & 1) || png_ptr->width < 2)
{
if (dsp_row != NULL)
png_combine_row(png_ptr, dsp_row,
png_pass_dsp_mask[png_ptr->pass]);
png_read_finish_row(png_ptr);
return;
}
break;
case 6:
if (!(png_ptr->row_number & 1))
{
png_read_finish_row(png_ptr);
return;
}
break;
}
}
#endif
if (!(png_ptr->mode & PNG_HAVE_IDAT))
png_error(png_ptr, "Invalid attempt to read row data");
png_ptr->zstream.next_out = png_ptr->row_buf;
png_ptr->zstream.avail_out = (uInt)png_ptr->irowbytes;
do
{
if (!(png_ptr->zstream.avail_in))
{
while (!png_ptr->idat_size)
{
png_byte chunk_length[4];
png_crc_finish(png_ptr, 0);
png_read_data(png_ptr, chunk_length, 4);
png_ptr->idat_size = png_get_uint_32(chunk_length);
png_reset_crc(png_ptr);
png_crc_read(png_ptr, png_ptr->chunk_name, 4);
if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
png_error(png_ptr, "Not enough image data");
}
png_ptr->zstream.avail_in = (uInt)png_ptr->zbuf_size;
png_ptr->zstream.next_in = png_ptr->zbuf;
if (png_ptr->zbuf_size > png_ptr->idat_size)
png_ptr->zstream.avail_in = (uInt)png_ptr->idat_size;
png_crc_read(png_ptr, png_ptr->zbuf,
(png_size_t)png_ptr->zstream.avail_in);
png_ptr->idat_size -= png_ptr->zstream.avail_in;
}
ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
if (ret == Z_STREAM_END)
{
if (png_ptr->zstream.avail_out || png_ptr->zstream.avail_in ||
png_ptr->idat_size)
png_error(png_ptr, "Extra compressed data");
png_ptr->mode |= PNG_AFTER_IDAT;
png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
break;
}
if (ret != Z_OK)
png_error(png_ptr, png_ptr->zstream.msg ? png_ptr->zstream.msg :
"Decompression error");
} while (png_ptr->zstream.avail_out);
png_ptr->row_info.color_type = png_ptr->color_type;
png_ptr->row_info.width = png_ptr->iwidth;
png_ptr->row_info.channels = png_ptr->channels;
png_ptr->row_info.bit_depth = png_ptr->bit_depth;
png_ptr->row_info.pixel_depth = png_ptr->pixel_depth;
png_ptr->row_info.rowbytes = ((png_ptr->row_info.width *
(png_uint_32)png_ptr->row_info.pixel_depth + 7) >> 3);
if(png_ptr->row_buf[0])
png_read_filter_row(png_ptr, &(png_ptr->row_info),
png_ptr->row_buf + 1, png_ptr->prev_row + 1,
(int)(png_ptr->row_buf[0]));
png_memcpy_check(png_ptr, png_ptr->prev_row, png_ptr->row_buf,
png_ptr->rowbytes + 1);
#if defined(PNG_MNG_FEATURES_SUPPORTED)
if((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
(png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING))
{
/* Intrapixel differencing */
png_do_read_intrapixel(&(png_ptr->row_info), png_ptr->row_buf + 1);
}
#endif
if (png_ptr->transformations)
png_do_read_transformations(png_ptr);
#if defined(PNG_READ_INTERLACING_SUPPORTED)
/* blow up interlaced rows to full size */
if (png_ptr->interlaced &&
(png_ptr->transformations & PNG_INTERLACE))
{
if (png_ptr->pass < 6)
/* old interface (pre-1.0.9):
png_do_read_interlace(&(png_ptr->row_info),
png_ptr->row_buf + 1, png_ptr->pass, png_ptr->transformations);
*/
png_do_read_interlace(png_ptr);
if (dsp_row != NULL)
png_combine_row(png_ptr, dsp_row,
png_pass_dsp_mask[png_ptr->pass]);
if (row != NULL)
png_combine_row(png_ptr, row,
png_pass_mask[png_ptr->pass]);
}
else
#endif
{
if (row != NULL)
png_combine_row(png_ptr, row, 0xff);
if (dsp_row != NULL)
png_combine_row(png_ptr, dsp_row, 0xff);
}
png_read_finish_row(png_ptr);
if (png_ptr->read_row_fn != NULL)
(*(png_ptr->read_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass);
}
/* 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
png_read_info(png_structp png_ptr, png_infop info_ptr)
{
png_debug(1, "in png_read_info\n");
/* save jump buffer and error functions */
/* 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");
}
}
for(;;)
{
png_byte chunk_length[4];
png_uint_32 length;
png_read_data(png_ptr, chunk_length, 4);
length = png_get_uint_32(chunk_length);
png_reset_crc(png_ptr);
png_crc_read(png_ptr, png_ptr->chunk_name, 4);
png_debug2(0, "Reading %s chunk, length=%d.\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_IHDR, 4))
png_handle_IHDR(png_ptr, info_ptr, length);
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_IEND, 4))
png_handle_IEND(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_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_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
else
png_handle_unknown(png_ptr, info_ptr, length);
}
}
