bool WEBPImageDecoder::updateDemuxer()
{
if (failed())
return false;
if (m_haveAlreadyParsedThisData)
return true;
m_haveAlreadyParsedThisData = true;
const unsigned webpHeaderSize = 30;
if (m_data->size() < webpHeaderSize)
return false; // Await VP8X header so WebPDemuxPartial succeeds.
WebPDemuxDelete(m_demux);
WebPData inputData = { reinterpret_cast<const uint8_t*>(m_data->data()), m_data->size() };
m_demux = WebPDemuxPartial(&inputData, &m_demuxState);
if (!m_demux || (isAllDataReceived() && m_demuxState != WEBP_DEMUX_DONE))
return setFailed();
ASSERT(m_demuxState > WEBP_DEMUX_PARSING_HEADER);
if (!WebPDemuxGetI(m_demux, WEBP_FF_FRAME_COUNT))
return false; // Wait until the encoded image frame data arrives.
if (!isDecodedSizeAvailable()) {
int width = WebPDemuxGetI(m_demux, WEBP_FF_CANVAS_WIDTH);
int height = WebPDemuxGetI(m_demux, WEBP_FF_CANVAS_HEIGHT);
if (!setSize(width, height))
return setFailed();
m_formatFlags = WebPDemuxGetI(m_demux, WEBP_FF_FORMAT_FLAGS);
if (!(m_formatFlags & ANIMATION_FLAG)) {
m_repetitionCount = cAnimationNone;
} else {
// Since we have parsed at least one frame, even if partially,
// the global animation (ANIM) properties have been read since
// an ANIM chunk must precede the ANMF frame chunks.
m_repetitionCount = WebPDemuxGetI(m_demux, WEBP_FF_LOOP_COUNT);
// Repetition count is always <= 16 bits.
ASSERT(m_repetitionCount == (m_repetitionCount & 0xffff));
// Repetition count is the number of animation cycles to show,
// where 0 means "infinite". But ImageSource::repetitionCount()
// returns -1 for "infinite", and 0 and up for "show the image
// animation one cycle more than the value". Subtract one here
// to correctly handle the finite and infinite cases.
--m_repetitionCount;
// FIXME: Implement ICC profile support for animated images.
m_formatFlags &= ~ICCP_FLAG;
}
#if USE(QCMSLIB)
if ((m_formatFlags & ICCP_FLAG) && !ignoresGammaAndColorProfile())
readColorProfile();
#endif
}
ASSERT(isDecodedSizeAvailable());
return true;
}
bool WEBPImageDecoder::decodeSingleFrame(const uint8_t* dataBytes, size_t dataSize, size_t frameIndex)
{
if (failed())
return false;
ASSERT(isDecodedSizeAvailable());
ASSERT(m_frameBufferCache.size() > frameIndex);
ImageFrame& buffer = m_frameBufferCache[frameIndex];
ASSERT(buffer.status() != ImageFrame::FrameComplete);
if (buffer.status() == ImageFrame::FrameEmpty) {
if (!buffer.setSize(size().width(), size().height()))
return setFailed();
buffer.setStatus(ImageFrame::FramePartial);
// The buffer is transparent outside the decoded area while the image is loading.
// The correct value of 'hasAlpha' for the frame will be set when it is fully decoded.
buffer.setHasAlpha(true);
buffer.setOriginalFrameRect(IntRect(IntPoint(), size()));
}
const IntRect& frameRect = buffer.originalFrameRect();
if (!m_decoder) {
WEBP_CSP_MODE mode = outputMode(m_formatFlags & ALPHA_FLAG);
if (!m_premultiplyAlpha)
mode = outputMode(false);
#if USE(QCMSLIB)
if (colorTransform())
mode = MODE_RGBA; // Decode to RGBA for input to libqcms.
#endif
WebPInitDecBuffer(&m_decoderBuffer);
m_decoderBuffer.colorspace = mode;
m_decoderBuffer.u.RGBA.stride = size().width() * sizeof(ImageFrame::PixelData);
m_decoderBuffer.u.RGBA.size = m_decoderBuffer.u.RGBA.stride * frameRect.height();
m_decoderBuffer.is_external_memory = 1;
m_decoder = WebPINewDecoder(&m_decoderBuffer);
if (!m_decoder)
return setFailed();
}
m_decoderBuffer.u.RGBA.rgba = reinterpret_cast<uint8_t*>(buffer.getAddr(frameRect.x(), frameRect.y()));
switch (WebPIUpdate(m_decoder, dataBytes, dataSize)) {
case VP8_STATUS_OK:
applyPostProcessing(frameIndex);
buffer.setHasAlpha((m_formatFlags & ALPHA_FLAG) || m_frameBackgroundHasAlpha);
buffer.setStatus(ImageFrame::FrameComplete);
clearDecoder();
return true;
case VP8_STATUS_SUSPENDED:
if (!isAllDataReceived() && !frameIsCompleteAtIndex(frameIndex)) {
applyPostProcessing(frameIndex);
return false;
}
// FALLTHROUGH
default:
clear();
return setFailed();
}
}
bool WEBPImageDecoder::decodeSingleFrame(const uint8_t* dataBytes,
size_t dataSize,
size_t frameIndex) {
if (failed())
return false;
ASSERT(isDecodedSizeAvailable());
ASSERT(m_frameBufferCache.size() > frameIndex);
ImageFrame& buffer = m_frameBufferCache[frameIndex];
ASSERT(buffer.getStatus() != ImageFrame::FrameComplete);
if (buffer.getStatus() == ImageFrame::FrameEmpty) {
if (!buffer.setSizeAndColorSpace(size().width(), size().height(),
colorSpace()))
return setFailed();
buffer.setStatus(ImageFrame::FramePartial);
// The buffer is transparent outside the decoded area while the image is
// loading. The correct alpha value for the frame will be set when it is
// fully decoded.
buffer.setHasAlpha(true);
buffer.setOriginalFrameRect(IntRect(IntPoint(), size()));
}
const IntRect& frameRect = buffer.originalFrameRect();
if (!m_decoder) {
WEBP_CSP_MODE mode = outputMode(m_formatFlags & ALPHA_FLAG);
if (!m_premultiplyAlpha)
mode = outputMode(false);
if (colorTransform()) {
// Swizzling between RGBA and BGRA is zero cost in a color transform.
// So when we have a color transform, we should decode to whatever is
// easiest for libwebp, and then let the color transform swizzle if
// necessary.
// Lossy webp is encoded as YUV (so RGBA and BGRA are the same cost).
// Lossless webp is encoded as BGRA. This means decoding to BGRA is
// either faster or the same cost as RGBA.
mode = MODE_BGRA;
}
WebPInitDecBuffer(&m_decoderBuffer);
m_decoderBuffer.colorspace = mode;
m_decoderBuffer.u.RGBA.stride =
size().width() * sizeof(ImageFrame::PixelData);
m_decoderBuffer.u.RGBA.size =
m_decoderBuffer.u.RGBA.stride * frameRect.height();
m_decoderBuffer.is_external_memory = 1;
m_decoder = WebPINewDecoder(&m_decoderBuffer);
if (!m_decoder)
return setFailed();
}
m_decoderBuffer.u.RGBA.rgba =
reinterpret_cast<uint8_t*>(buffer.getAddr(frameRect.x(), frameRect.y()));
switch (WebPIUpdate(m_decoder, dataBytes, dataSize)) {
case VP8_STATUS_OK:
applyPostProcessing(frameIndex);
buffer.setHasAlpha((m_formatFlags & ALPHA_FLAG) ||
m_frameBackgroundHasAlpha);
buffer.setStatus(ImageFrame::FrameComplete);
clearDecoder();
return true;
case VP8_STATUS_SUSPENDED:
if (!isAllDataReceived() && !frameIsCompleteAtIndex(frameIndex)) {
applyPostProcessing(frameIndex);
return false;
}
// FALLTHROUGH
default:
clear();
return setFailed();
}
}
bool WEBPImageDecoder::updateDemuxer() {
if (failed())
return false;
if (m_haveAlreadyParsedThisData)
return true;
m_haveAlreadyParsedThisData = true;
const unsigned webpHeaderSize = 30;
if (m_data->size() < webpHeaderSize)
return false; // Await VP8X header so WebPDemuxPartial succeeds.
WebPDemuxDelete(m_demux);
m_consolidatedData = m_data->getAsSkData();
WebPData inputData = {
reinterpret_cast<const uint8_t*>(m_consolidatedData->data()),
m_consolidatedData->size()};
m_demux = WebPDemuxPartial(&inputData, &m_demuxState);
if (!m_demux || (isAllDataReceived() && m_demuxState != WEBP_DEMUX_DONE)) {
if (!m_demux)
m_consolidatedData.reset();
return setFailed();
}
ASSERT(m_demuxState > WEBP_DEMUX_PARSING_HEADER);
if (!WebPDemuxGetI(m_demux, WEBP_FF_FRAME_COUNT))
return false; // Wait until the encoded image frame data arrives.
if (!isDecodedSizeAvailable()) {
int width = WebPDemuxGetI(m_demux, WEBP_FF_CANVAS_WIDTH);
int height = WebPDemuxGetI(m_demux, WEBP_FF_CANVAS_HEIGHT);
if (!setSize(width, height))
return setFailed();
m_formatFlags = WebPDemuxGetI(m_demux, WEBP_FF_FORMAT_FLAGS);
if (!(m_formatFlags & ANIMATION_FLAG)) {
m_repetitionCount = cAnimationNone;
} else {
// Since we have parsed at least one frame, even if partially,
// the global animation (ANIM) properties have been read since
// an ANIM chunk must precede the ANMF frame chunks.
m_repetitionCount = WebPDemuxGetI(m_demux, WEBP_FF_LOOP_COUNT);
// Repetition count is always <= 16 bits.
ASSERT(m_repetitionCount == (m_repetitionCount & 0xffff));
if (!m_repetitionCount)
m_repetitionCount = cAnimationLoopInfinite;
// FIXME: Implement ICC profile support for animated images.
m_formatFlags &= ~ICCP_FLAG;
}
if ((m_formatFlags & ICCP_FLAG) && !ignoresColorSpace())
readColorProfile();
}
ASSERT(isDecodedSizeAvailable());
size_t frameCount = WebPDemuxGetI(m_demux, WEBP_FF_FRAME_COUNT);
updateAggressivePurging(frameCount);
return true;
}