// got the header of a new frame that's coming
void
nsPNGDecoder::frame_info_callback(png_structp png_ptr, png_uint_32 frame_num)
{
png_uint_32 x_offset, y_offset;
int32_t width, height;
nsPNGDecoder* decoder =
static_cast<nsPNGDecoder*>(png_get_progressive_ptr(png_ptr));
// old frame is done
decoder->EndImageFrame();
// Only the first frame can be hidden, so unhide unconditionally here.
decoder->mFrameIsHidden = false;
x_offset = png_get_next_frame_x_offset(png_ptr, decoder->mInfo);
y_offset = png_get_next_frame_y_offset(png_ptr, decoder->mInfo);
width = png_get_next_frame_width(png_ptr, decoder->mInfo);
height = png_get_next_frame_height(png_ptr, decoder->mInfo);
decoder->CreateFrame(x_offset, y_offset, width, height, decoder->format);
if (decoder->NeedsNewFrame()) {
// We know that we need a new frame, so pause input so the decoder
// infrastructure can give it to us.
png_process_data_pause(png_ptr, /* save = */ 1);
}
}
void pngDecInfoCallback(png_structp png_ptr, png_infop info)
{
PngStream* stream = (PngStream*)png_get_progressive_ptr(png_ptr);
if (!stream)
{
cellPngDec.error("Failed to obtain streamPtr in rowCallback.");
return;
}
const size_t remaining = png_process_data_pause(png_ptr, false);
stream->buffer->cursor += (stream->buffer->length - remaining);
}
void PNGImageDecoder::headerAvailable()
{
png_structp png = m_reader->pngPtr();
png_infop info = m_reader->infoPtr();
png_uint_32 width = png_get_image_width(png, info);
png_uint_32 height = png_get_image_height(png, info);
// Protect against large PNGs. See http://bugzil.la/251381 for more details.
const unsigned long maxPNGSize = 1000000UL;
if (width > maxPNGSize || height > maxPNGSize) {
longjmp(JMPBUF(png), 1);
return;
}
// Set the image size now that the image header is available.
if (!setSize(width, height)) {
longjmp(JMPBUF(png), 1);
return;
}
int bitDepth, colorType, interlaceType, compressionType, filterType, channels;
png_get_IHDR(png, info, &width, &height, &bitDepth, &colorType, &interlaceType, &compressionType, &filterType);
// The options we set here match what Mozilla does.
// Expand to ensure we use 24-bit for RGB and 32-bit for RGBA.
if (colorType == PNG_COLOR_TYPE_PALETTE || (colorType == PNG_COLOR_TYPE_GRAY && bitDepth < 8))
png_set_expand(png);
png_bytep trns = 0;
int trnsCount = 0;
if (png_get_valid(png, info, PNG_INFO_tRNS)) {
png_get_tRNS(png, info, &trns, &trnsCount, 0);
png_set_expand(png);
}
if (bitDepth == 16)
png_set_strip_16(png);
if (colorType == PNG_COLOR_TYPE_GRAY || colorType == PNG_COLOR_TYPE_GRAY_ALPHA)
png_set_gray_to_rgb(png);
#if USE(QCMSLIB)
if ((colorType & PNG_COLOR_MASK_COLOR) && !m_ignoreGammaAndColorProfile) {
// We only support color profiles for color PALETTE and RGB[A] PNG. Supporting
// color profiles for gray-scale images is slightly tricky, at least using the
// CoreGraphics ICC library, because we expand gray-scale images to RGB but we
// do not similarly transform the color profile. We'd either need to transform
// the color profile or we'd need to decode into a gray-scale image buffer and
// hand that to CoreGraphics.
bool sRGB = false;
ColorProfile colorProfile;
getColorProfile(png, info, colorProfile, sRGB);
bool imageHasAlpha = (colorType & PNG_COLOR_MASK_ALPHA) || trnsCount;
m_reader->createColorTransform(colorProfile, imageHasAlpha, sRGB);
m_hasColorProfile = !!m_reader->colorTransform();
}
#endif
if (!m_hasColorProfile) {
// Deal with gamma and keep it under our control.
const double inverseGamma = 0.45455;
const double defaultGamma = 2.2;
double gamma;
if (!m_ignoreGammaAndColorProfile && png_get_gAMA(png, info, &gamma)) {
const double maxGamma = 21474.83;
if ((gamma <= 0.0) || (gamma > maxGamma)) {
gamma = inverseGamma;
png_set_gAMA(png, info, gamma);
}
png_set_gamma(png, defaultGamma, gamma);
} else {
png_set_gamma(png, defaultGamma, inverseGamma);
}
}
// Tell libpng to send us rows for interlaced pngs.
if (interlaceType == PNG_INTERLACE_ADAM7)
png_set_interlace_handling(png);
// Update our info now.
png_read_update_info(png, info);
channels = png_get_channels(png, info);
ASSERT(channels == 3 || channels == 4);
m_reader->setHasAlpha(channels == 4);
if (m_reader->decodingSizeOnly()) {
// If we only needed the size, halt the reader.
#if PNG_LIBPNG_VER_MAJOR > 1 || (PNG_LIBPNG_VER_MAJOR == 1 && PNG_LIBPNG_VER_MINOR >= 5)
// '0' argument to png_process_data_pause means: Do not cache unprocessed data.
m_reader->setReadOffset(m_reader->currentBufferSize() - png_process_data_pause(png, 0));
#else
m_reader->setReadOffset(m_reader->currentBufferSize() - png->buffer_size);
png->buffer_size = 0;
#endif
}
}
void PNGImageDecoder::headerAvailable()
{
png_structp png = m_reader->pngPtr();
png_infop info = m_reader->infoPtr();
png_uint_32 width = png_get_image_width(png, info);
png_uint_32 height = png_get_image_height(png, info);
// Protect against large images.
if (width > cMaxPNGSize || height > cMaxPNGSize) {
longjmp(JMPBUF(png), 1);
return;
}
// We can fill in the size now that the header is available. Avoid memory
// corruption issues by neutering setFailed() during this call; if we don't
// do this, failures will cause |m_reader| to be deleted, and our jmpbuf
// will cease to exist. Note that we'll still properly set the failure flag
// in this case as soon as we longjmp().
m_doNothingOnFailure = true;
bool result = setSize(width, height);
m_doNothingOnFailure = false;
if (!result) {
longjmp(JMPBUF(png), 1);
return;
}
int bitDepth, colorType, interlaceType, compressionType, filterType, channels;
png_get_IHDR(png, info, &width, &height, &bitDepth, &colorType, &interlaceType, &compressionType, &filterType);
if ((colorType == PNG_COLOR_TYPE_RGB || colorType == PNG_COLOR_TYPE_RGB_ALPHA) && !m_ignoreGammaAndColorProfile) {
// We currently support color profiles only for RGB and RGBA PNGs. Supporting
// color profiles for gray-scale images is slightly tricky, at least using the
// CoreGraphics ICC library, because we expand gray-scale images to RGB but we
// don't similarly transform the color profile. We'd either need to transform
// the color profile or we'd need to decode into a gray-scale image buffer and
// hand that to CoreGraphics.
m_colorProfile = readColorProfile(png, info);
}
// The options we set here match what Mozilla does.
// Expand to ensure we use 24-bit for RGB and 32-bit for RGBA.
if (colorType == PNG_COLOR_TYPE_PALETTE || (colorType == PNG_COLOR_TYPE_GRAY && bitDepth < 8))
png_set_expand(png);
png_bytep trns = 0;
int trnsCount = 0;
if (png_get_valid(png, info, PNG_INFO_tRNS)) {
png_get_tRNS(png, info, &trns, &trnsCount, 0);
png_set_expand(png);
}
if (bitDepth == 16)
png_set_strip_16(png);
if (colorType == PNG_COLOR_TYPE_GRAY || colorType == PNG_COLOR_TYPE_GRAY_ALPHA)
png_set_gray_to_rgb(png);
// Deal with gamma and keep it under our control.
double gamma;
if (!m_ignoreGammaAndColorProfile && png_get_gAMA(png, info, &gamma)) {
if ((gamma <= 0.0) || (gamma > cMaxGamma)) {
gamma = cInverseGamma;
png_set_gAMA(png, info, gamma);
}
png_set_gamma(png, cDefaultGamma, gamma);
} else
png_set_gamma(png, cDefaultGamma, cInverseGamma);
// Tell libpng to send us rows for interlaced pngs.
if (interlaceType == PNG_INTERLACE_ADAM7)
png_set_interlace_handling(png);
// Update our info now.
png_read_update_info(png, info);
channels = png_get_channels(png, info);
ASSERT(channels == 3 || channels == 4);
m_reader->setHasAlpha(channels == 4);
if (m_reader->decodingSizeOnly()) {
// If we only needed the size, halt the reader.
#if defined(PNG_LIBPNG_VER_MAJOR) && defined(PNG_LIBPNG_VER_MINOR) && (PNG_LIBPNG_VER_MAJOR > 1 || (PNG_LIBPNG_VER_MAJOR == 1 && PNG_LIBPNG_VER_MINOR >= 5))
// '0' argument to png_process_data_pause means: Do not cache unprocessed data.
m_reader->setReadOffset(m_reader->currentBufferSize() - png_process_data_pause(png, 0));
#else
m_reader->setReadOffset(m_reader->currentBufferSize() - png->buffer_size);
png->buffer_size = 0;
#endif
}
}
void
nsPNGDecoder::info_callback(png_structp png_ptr, png_infop info_ptr)
{
// int number_passes; NOT USED
png_uint_32 width, height;
int bit_depth, color_type, interlace_type, compression_type, filter_type;
unsigned int channels;
png_bytep trans = nullptr;
int num_trans = 0;
nsPNGDecoder* decoder =
static_cast<nsPNGDecoder*>(png_get_progressive_ptr(png_ptr));
// Always decode to 24-bit RGB or 32-bit RGBA
png_get_IHDR(png_ptr, info_ptr, &width, &height, &bit_depth, &color_type,
&interlace_type, &compression_type, &filter_type);
// Are we too big?
if (width > MOZ_PNG_MAX_DIMENSION || height > MOZ_PNG_MAX_DIMENSION) {
png_longjmp(decoder->mPNG, 1);
}
// Post our size to the superclass
decoder->PostSize(width, height);
if (decoder->HasError()) {
// Setting the size led to an error.
png_longjmp(decoder->mPNG, 1);
}
if (color_type == PNG_COLOR_TYPE_PALETTE) {
png_set_expand(png_ptr);
}
if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8) {
png_set_expand(png_ptr);
}
if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)) {
png_color_16p trans_values;
png_get_tRNS(png_ptr, info_ptr, &trans, &num_trans, &trans_values);
// libpng doesn't reject a tRNS chunk with out-of-range samples
// so we check it here to avoid setting up a useless opacity
// channel or producing unexpected transparent pixels (bug #428045)
if (bit_depth < 16) {
png_uint_16 sample_max = (1 << bit_depth) - 1;
if ((color_type == PNG_COLOR_TYPE_GRAY &&
trans_values->gray > sample_max) ||
(color_type == PNG_COLOR_TYPE_RGB &&
(trans_values->red > sample_max ||
trans_values->green > sample_max ||
trans_values->blue > sample_max))) {
// clear the tRNS valid flag and release tRNS memory
png_free_data(png_ptr, info_ptr, PNG_FREE_TRNS, 0);
num_trans = 0;
}
}
if (num_trans != 0) {
png_set_expand(png_ptr);
}
}
if (bit_depth == 16) {
png_set_scale_16(png_ptr);
}
qcms_data_type inType = QCMS_DATA_RGBA_8;
uint32_t intent = -1;
uint32_t pIntent;
if (decoder->mCMSMode != eCMSMode_Off) {
intent = gfxPlatform::GetRenderingIntent();
decoder->mInProfile = PNGGetColorProfile(png_ptr, info_ptr,
color_type, &inType, &pIntent);
// If we're not mandating an intent, use the one from the image.
if (intent == uint32_t(-1)) {
intent = pIntent;
}
}
if (decoder->mInProfile && gfxPlatform::GetCMSOutputProfile()) {
qcms_data_type outType;
if (color_type & PNG_COLOR_MASK_ALPHA || num_trans) {
outType = QCMS_DATA_RGBA_8;
} else {
outType = QCMS_DATA_RGB_8;
}
decoder->mTransform = qcms_transform_create(decoder->mInProfile,
inType,
gfxPlatform::GetCMSOutputProfile(),
outType,
(qcms_intent)intent);
} else {
png_set_gray_to_rgb(png_ptr);
// only do gamma correction if CMS isn't entirely disabled
if (decoder->mCMSMode != eCMSMode_Off) {
PNGDoGammaCorrection(png_ptr, info_ptr);
}
if (decoder->mCMSMode == eCMSMode_All) {
if (color_type & PNG_COLOR_MASK_ALPHA || num_trans) {
decoder->mTransform = gfxPlatform::GetCMSRGBATransform();
} else {
decoder->mTransform = gfxPlatform::GetCMSRGBTransform();
}
}
}
// let libpng expand interlaced images
if (interlace_type == PNG_INTERLACE_ADAM7) {
// number_passes =
png_set_interlace_handling(png_ptr);
}
// now all of those things we set above are used to update various struct
// members and whatnot, after which we can get channels, rowbytes, etc.
png_read_update_info(png_ptr, info_ptr);
decoder->mChannels = channels = png_get_channels(png_ptr, info_ptr);
//---------------------------------------------------------------//
// copy PNG info into imagelib structs (formerly png_set_dims()) //
//---------------------------------------------------------------//
if (channels == 1 || channels == 3) {
decoder->format = gfx::SurfaceFormat::B8G8R8X8;
} else if (channels == 2 || channels == 4) {
decoder->format = gfx::SurfaceFormat::B8G8R8A8;
} else {
png_longjmp(decoder->mPNG, 1); // invalid number of channels
}
#ifdef PNG_APNG_SUPPORTED
if (png_get_valid(png_ptr, info_ptr, PNG_INFO_acTL)) {
png_set_progressive_frame_fn(png_ptr, nsPNGDecoder::frame_info_callback,
nullptr);
}
if (png_get_first_frame_is_hidden(png_ptr, info_ptr)) {
decoder->mFrameIsHidden = true;
} else {
#endif
decoder->CreateFrame(0, 0, width, height, decoder->format);
#ifdef PNG_APNG_SUPPORTED
}
#endif
if (decoder->mTransform &&
(channels <= 2 || interlace_type == PNG_INTERLACE_ADAM7)) {
uint32_t bpp[] = { 0, 3, 4, 3, 4 };
decoder->mCMSLine =
(uint8_t*)malloc(bpp[channels] * width);
if (!decoder->mCMSLine) {
png_longjmp(decoder->mPNG, 5); // NS_ERROR_OUT_OF_MEMORY
}
}
if (interlace_type == PNG_INTERLACE_ADAM7) {
if (height < INT32_MAX / (width * channels)) {
decoder->interlacebuf = (uint8_t*)malloc(channels * width * height);
}
if (!decoder->interlacebuf) {
png_longjmp(decoder->mPNG, 5); // NS_ERROR_OUT_OF_MEMORY
}
}
if (decoder->NeedsNewFrame()) {
// We know that we need a new frame, so pause input so the decoder
// infrastructure can give it to us.
png_process_data_pause(png_ptr, /* save = */ 1);
}
}
void AutoCleanPng::infoCallback() {
png_uint_32 origWidth, origHeight;
int bitDepth, encodedColorType;
png_get_IHDR(fPng_ptr, fInfo_ptr, &origWidth, &origHeight, &bitDepth,
&encodedColorType, nullptr, nullptr, nullptr);
// Tell libpng to strip 16 bit/color files down to 8 bits/color.
// TODO: Should we handle this in SkSwizzler? Could this also benefit
// RAW decodes?
if (bitDepth == 16) {
SkASSERT(PNG_COLOR_TYPE_PALETTE != encodedColorType);
png_set_strip_16(fPng_ptr);
}
// Now determine the default colorType and alphaType and set the required transforms.
// Often, we depend on SkSwizzler to perform any transforms that we need. However, we
// still depend on libpng for many of the rare and PNG-specific cases.
SkEncodedInfo::Color color;
SkEncodedInfo::Alpha alpha;
switch (encodedColorType) {
case PNG_COLOR_TYPE_PALETTE:
// Extract multiple pixels with bit depths of 1, 2, and 4 from a single
// byte into separate bytes (useful for paletted and grayscale images).
if (bitDepth < 8) {
// TODO: Should we use SkSwizzler here?
png_set_packing(fPng_ptr);
}
color = SkEncodedInfo::kPalette_Color;
// Set the alpha depending on if a transparency chunk exists.
alpha = png_get_valid(fPng_ptr, fInfo_ptr, PNG_INFO_tRNS) ?
SkEncodedInfo::kUnpremul_Alpha : SkEncodedInfo::kOpaque_Alpha;
break;
case PNG_COLOR_TYPE_RGB:
if (png_get_valid(fPng_ptr, fInfo_ptr, PNG_INFO_tRNS)) {
// Convert to RGBA if transparency chunk exists.
png_set_tRNS_to_alpha(fPng_ptr);
color = SkEncodedInfo::kRGBA_Color;
alpha = SkEncodedInfo::kBinary_Alpha;
} else {
color = SkEncodedInfo::kRGB_Color;
alpha = SkEncodedInfo::kOpaque_Alpha;
}
break;
case PNG_COLOR_TYPE_GRAY:
// Expand grayscale images to the full 8 bits from 1, 2, or 4 bits/pixel.
if (bitDepth < 8) {
// TODO: Should we use SkSwizzler here?
png_set_expand_gray_1_2_4_to_8(fPng_ptr);
}
if (png_get_valid(fPng_ptr, fInfo_ptr, PNG_INFO_tRNS)) {
png_set_tRNS_to_alpha(fPng_ptr);
color = SkEncodedInfo::kGrayAlpha_Color;
alpha = SkEncodedInfo::kBinary_Alpha;
} else {
color = SkEncodedInfo::kGray_Color;
alpha = SkEncodedInfo::kOpaque_Alpha;
}
break;
case PNG_COLOR_TYPE_GRAY_ALPHA:
color = SkEncodedInfo::kGrayAlpha_Color;
alpha = SkEncodedInfo::kUnpremul_Alpha;
break;
case PNG_COLOR_TYPE_RGBA:
color = SkEncodedInfo::kRGBA_Color;
alpha = SkEncodedInfo::kUnpremul_Alpha;
break;
default:
// All the color types have been covered above.
SkASSERT(false);
color = SkEncodedInfo::kRGBA_Color;
alpha = SkEncodedInfo::kUnpremul_Alpha;
}
const int numberPasses = png_set_interlace_handling(fPng_ptr);
if (fOutCodec) {
SkASSERT(nullptr == *fOutCodec);
sk_sp<SkColorSpace> colorSpace = read_color_space(fPng_ptr, fInfo_ptr);
if (!colorSpace) {
// Treat unmarked pngs as sRGB.
colorSpace = SkColorSpace::NewNamed(SkColorSpace::kSRGB_Named);
}
SkEncodedInfo info = SkEncodedInfo::Make(color, alpha, 8);
if (1 == numberPasses) {
*fOutCodec = new SkPngNormalDecoder(origWidth, origHeight, info, fStream,
fChunkReader, fPng_ptr, fInfo_ptr, bitDepth, std::move(colorSpace));
} else {
*fOutCodec = new SkPngInterlacedDecoder(origWidth, origHeight, info, fStream,
fChunkReader, fPng_ptr, fInfo_ptr, bitDepth, std::move(colorSpace),
numberPasses);
}
}
fDecodedBounds = true;
// 1 tells libpng to save any extra data. We may be able to be more efficient by saving
// it ourselves.
png_process_data_pause(fPng_ptr, 1);
// Release the pointers, which are now owned by the codec or the caller is expected to
// take ownership.
this->releasePngPtrs();
}
