bool decode(const SharedBuffer& data, bool sizeOnly)
    {
        m_decodingSizeOnly = sizeOnly;

        // We need to do the setjmp here. Otherwise bad things will happen.
        if (setjmp(JMPBUF(m_png)))
            return m_decoder->setFailed();

        const char* segment;
        while (unsigned segmentLength = data.getSomeData(segment, m_readOffset)) {
            m_readOffset += segmentLength;
            m_currentBufferSize = m_readOffset;
            png_process_data(m_png, m_info, reinterpret_cast<png_bytep>(const_cast<char*>(segment)), segmentLength);
            if (sizeOnly ? m_decoder->isDecodedSizeAvailable() : m_decoder->frameIsCompleteAtIndex(0))
                return true;
        }

        return false;
    }
Example #2
0
    bool decode(const SharedBuffer& data, bool sizeOnly)
    {
        m_decodingSizeOnly = sizeOnly;
        PNGImageDecoder* decoder = static_cast<PNGImageDecoder*>(png_get_progressive_ptr(m_png));

        // We need to do the setjmp here. Otherwise bad things will happen.
        if (setjmp(JMPBUF(m_png)))
            return decoder->setFailed();

        const char* segment;
        while (unsigned segmentLength = data.getSomeData(segment, m_readOffset)) {
            m_readOffset += segmentLength;
            m_currentBufferSize = m_readOffset;
            png_process_data(m_png, m_info, reinterpret_cast<png_bytep>(const_cast<char*>(segment)), segmentLength);
            // We explicitly specify the superclass isSizeAvailable() because we
            // merely want to check if we've managed to set the size, not
            // (recursively) trigger additional decoding if we haven't.
            if (sizeOnly ? decoder->ImageDecoder::isSizeAvailable() : decoder->isComplete())
                return true;
        }
        return false;
    }
void PNGImageDecoder::rowAvailable(unsigned char* rowBuffer, unsigned rowIndex, int)
{
    if (m_frameBufferCache.isEmpty())
        return;

    // Initialize the framebuffer if needed.
    ImageFrame& buffer = m_frameBufferCache[0];
    if (buffer.status() == ImageFrame::FrameEmpty) {
        png_structp png = m_reader->pngPtr();
        if (!buffer.setSize(size().width(), size().height())) {
            longjmp(JMPBUF(png), 1);
            return;
        }

        unsigned colorChannels = m_reader->hasAlpha() ? 4 : 3;
        if (PNG_INTERLACE_ADAM7 == png_get_interlace_type(png, m_reader->infoPtr())) {
            m_reader->createInterlaceBuffer(colorChannels * size().width() * size().height());
            if (!m_reader->interlaceBuffer()) {
                longjmp(JMPBUF(png), 1);
                return;
            }
        }

#if USE(QCMSLIB)
        if (m_reader->colorTransform()) {
            m_reader->createRowBuffer(colorChannels * size().width());
            if (!m_reader->rowBuffer()) {
                longjmp(JMPBUF(png), 1);
                return;
            }
        }
#endif
        buffer.setStatus(ImageFrame::FramePartial);
        buffer.setHasAlpha(false);

        // For PNGs, the frame always fills the entire image.
        buffer.setOriginalFrameRect(IntRect(IntPoint(), size()));
    }

    /* libpng comments (here to explain what follows).
     *
     * this function is called for every row in the image. If the
     * image is interlacing, and you turned on the interlace handler,
     * this function will be called for every row in every pass.
     * Some of these rows will not be changed from the previous pass.
     * When the row is not changed, the new_row variable will be NULL.
     * The rows and passes are called in order, so you don't really
     * need the row_num and pass, but I'm supplying them because it
     * may make your life easier.
     */

    // Nothing to do if the row is unchanged, or the row is outside
    // the image bounds: libpng may send extra rows, ignore them to
    // make our lives easier.
    if (!rowBuffer)
        return;
    int y = rowIndex;
    if (y < 0 || y >= size().height())
        return;

    /* libpng comments (continued).
     *
     * For the non-NULL rows of interlaced images, you must call
     * png_progressive_combine_row() passing in the row and the
     * old row.  You can call this function for NULL rows (it will
     * just return) and for non-interlaced images (it just does the
     * memcpy for you) if it will make the code easier. Thus, you
     * can just do this for all cases:
     *
     *    png_progressive_combine_row(png_ptr, old_row, new_row);
     *
     * where old_row is what was displayed for previous rows. Note
     * that the first pass (pass == 0 really) will completely cover
     * the old row, so the rows do not have to be initialized. After
     * the first pass (and only for interlaced images), you will have
     * to pass the current row, and the function will combine the
     * old row and the new row.
     */

    bool hasAlpha = m_reader->hasAlpha();
    png_bytep row = rowBuffer;

    if (png_bytep interlaceBuffer = m_reader->interlaceBuffer()) {
        unsigned colorChannels = hasAlpha ? 4 : 3;
        row = interlaceBuffer + (rowIndex * colorChannels * size().width());
        png_progressive_combine_row(m_reader->pngPtr(), row, rowBuffer);
    }

#if USE(QCMSLIB)
    if (qcms_transform* transform = m_reader->colorTransform()) {
        qcms_transform_data(transform, row, m_reader->rowBuffer(), size().width());
        row = m_reader->rowBuffer();
    }
#endif

    // Write the decoded row pixels to the frame buffer. The repetitive
    // form of the row write loops is for speed.
    ImageFrame::PixelData* address = buffer.getAddr(0, y);
    unsigned alphaMask = 255;
    int width = size().width();

    png_bytep pixel = row;
    if (hasAlpha) {
        if (buffer.premultiplyAlpha()) {
            for (int x = 0; x < width; ++x, pixel += 4) {
                buffer.setRGBAPremultiply(address++, pixel[0], pixel[1], pixel[2], pixel[3]);
                alphaMask &= pixel[3];
            }
        } else {
            for (int x = 0; x < width; ++x, pixel += 4) {
                buffer.setRGBARaw(address++, pixel[0], pixel[1], pixel[2], pixel[3]);
                alphaMask &= pixel[3];
            }
        }
    } else {
        for (int x = 0; x < width; ++x, pixel += 3) {
            buffer.setRGBARaw(address++, pixel[0], pixel[1], pixel[2], 255);
        }
    }

    if (alphaMask != 255 && !buffer.hasAlpha())
        buffer.setHasAlpha(true);

    buffer.setPixelsChanged(true);
}
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
    }
}
Example #5
0
// Called if the decoding of the image fails.
static void PNGAPI decodingFailed(png_structp png, png_const_charp)
{
    longjmp(JMPBUF(png), 1);
}
Example #6
0
void PNGImageDecoder::rowAvailable(unsigned char* rowBuffer, unsigned rowIndex, int interlacePass)
{
    if (m_frameBufferCache.isEmpty())
        return;

    // Initialize the framebuffer if needed.
    ImageFrame& buffer = m_frameBufferCache[0];
    if (buffer.status() == ImageFrame::FrameEmpty) {
        if (!buffer.setSize(scaledSize().width(), scaledSize().height())) {
            longjmp(JMPBUF(m_reader->pngPtr()), 1);
            return;
        }
        buffer.setStatus(ImageFrame::FramePartial);
        buffer.setHasAlpha(false);
        buffer.setColorProfile(m_colorProfile);

        // For PNGs, the frame always fills the entire image.
        buffer.setOriginalFrameRect(IntRect(IntPoint(), size()));

        if (png_get_interlace_type(m_reader->pngPtr(), m_reader->infoPtr()) != PNG_INTERLACE_NONE)
            m_reader->createInterlaceBuffer((m_reader->hasAlpha() ? 4 : 3) * size().width() * size().height());
    }

    if (!rowBuffer)
        return;

    // libpng comments (pasted in here to explain what follows)
    /*
     * this function is called for every row in the image.  If the
     * image is interlacing, and you turned on the interlace handler,
     * this function will be called for every row in every pass.
     * Some of these rows will not be changed from the previous pass.
     * When the row is not changed, the new_row variable will be NULL.
     * The rows and passes are called in order, so you don't really
     * need the row_num and pass, but I'm supplying them because it
     * may make your life easier.
     *
     * For the non-NULL rows of interlaced images, you must call
     * png_progressive_combine_row() passing in the row and the
     * old row.  You can call this function for NULL rows (it will
     * just return) and for non-interlaced images (it just does the
     * memcpy for you) if it will make the code easier.  Thus, you
     * can just do this for all cases:
     *
     *    png_progressive_combine_row(png_ptr, old_row, new_row);
     *
     * where old_row is what was displayed for previous rows.  Note
     * that the first pass (pass == 0 really) will completely cover
     * the old row, so the rows do not have to be initialized.  After
     * the first pass (and only for interlaced images), you will have
     * to pass the current row, and the function will combine the
     * old row and the new row.
     */

    png_structp png = m_reader->pngPtr();
    bool hasAlpha = m_reader->hasAlpha();
    unsigned colorChannels = hasAlpha ? 4 : 3;
    png_bytep row;
    png_bytep interlaceBuffer = m_reader->interlaceBuffer();
    if (interlaceBuffer) {
        row = interlaceBuffer + (rowIndex * colorChannels * size().width());
        png_progressive_combine_row(png, row, rowBuffer);
    } else
        row = rowBuffer;

    // Copy the data into our buffer.
    int width = scaledSize().width();
    int destY = scaledY(rowIndex);

    // Check that the row is within the image bounds. LibPNG may supply an extra row.
    if (destY < 0 || destY >= scaledSize().height())
        return;
    bool nonTrivialAlpha = false;
    for (int x = 0; x < width; ++x) {
        png_bytep pixel = row + (m_scaled ? m_scaledColumns[x] : x) * colorChannels;
        unsigned alpha = hasAlpha ? pixel[3] : 255;
        buffer.setRGBA(x, destY, pixel[0], pixel[1], pixel[2], alpha);
        nonTrivialAlpha |= alpha < 255;
    }
    if (nonTrivialAlpha && !buffer.hasAlpha())
        buffer.setHasAlpha(nonTrivialAlpha);
}
Example #7
0
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
    }
}
Example #8
0
void PNGImageDecoder::headerAvailable()
{
    png_structp png = m_reader->pngPtr();
    png_infop info = m_reader->infoPtr();
    png_uint_32 width = png->width;
    png_uint_32 height = png->height;
    
    // Protect against large images.
    if (png->width > cMaxPNGSize || png->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);

    // 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 (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.     
        m_reader->setReadOffset(m_reader->currentBufferSize() - png->buffer_size);
        png->buffer_size = 0;
    }
}