// Callbacks from the GIF reader.
bool GIFImageDecoder::sizeNowAvailable(unsigned width, unsigned height)
{
    if (!setSize(width, height))
        return false;
    prepareScaleDataIfNecessary();
    return true;
}
示例#2
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bool PNGImageDecoder::setSize(unsigned width, unsigned height)
{
    if (!ImageDecoder::setSize(width, height))
        return false;

    prepareScaleDataIfNecessary();
    return true;
}
示例#3
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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;
}
示例#4
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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;
}
示例#5
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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());
}
示例#6
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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;
}
示例#7
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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
    }
}