// Callbacks from the GIF reader.
bool GIFImageDecoder::sizeNowAvailable(unsigned width, unsigned height)
{
if (!setSize(width, height))
return false;
prepareScaleDataIfNecessary();
return true;
}
bool PNGImageDecoder::setSize(unsigned width, unsigned height)
{
if (!ImageDecoder::setSize(width, height))
return false;
prepareScaleDataIfNecessary();
return true;
}
bool GIFImageDecoder::setSize(unsigned width, unsigned height)
{
if (ImageDecoder::isSizeAvailable() && size() == IntSize(width, height))
return true;
if (!ImageDecoder::setSize(width, height))
return false;
prepareScaleDataIfNecessary();
return true;
}
bool GIFImageDecoder::setSize(int width, int height)
{
if (ImageDecoder::isSizeAvailable() && size().width() == width && size().height() == height)
return true;
if (!ImageDecoder::setSize(width, height))
return false;
prepareScaleDataIfNecessary();
return true;
}
void ImageDecoderQt::internalDecodeSize()
{
ASSERT(m_reader);
// If we have a QSize() something failed
QSize size = m_reader->size();
if (size.isEmpty()) {
setFailed();
return clearPointers();
}
setSize(size.width(), size.height());
// We don't need the tables set by prepareScaleDataIfNecessary,
// but their dimensions are used by ImageDecoder::scaledSize().
prepareScaleDataIfNecessary();
if (m_scaled)
m_reader->setScaledSize(scaledSize());
}
ImageFrame* PNGImageDecoder::frameBufferAtIndex(size_t index, const FloatSize& reqFrameSize)
{
#if ENABLE(IMAGE_DECODER_DOWN_SAMPLING)
prepareScaleDataIfNecessary(reqFrameSize);
#endif
if (index)
return 0;
if (m_frameBufferCache.isEmpty()) {
m_frameBufferCache.resize(1);
m_frameBufferCache[0].setPremultiplyAlpha(m_premultiplyAlpha);
}
ImageFrame& frame = m_frameBufferCache[0];
if (frame.status() != ImageFrame::FrameComplete) {
PlatformInstrumentation::willDecodeImage("PNG");
decode(false);
PlatformInstrumentation::didDecodeImage();
}
return &frame;
}
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);
#if ENABLE(IMAGE_DECODER_DOWN_SAMPLING)
prepareScaleDataIfNecessary(FloatSize(requestedFrameSize().width(), requestedFrameSize().height()));
#endif
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);
// 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 ((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.
readColorProfile(png, info, m_colorProfile);
#if USE(QCMSLIB)
bool decodedImageHasAlpha = (colorType & PNG_COLOR_MASK_ALPHA) || trnsCount;
m_reader->createColorTransform(m_colorProfile, decodedImageHasAlpha);
m_colorProfile.clear();
#endif
}
// 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
}
}
