void GIFImageDecoder::decode(size_t index)
{
parse(GIFFrameCountQuery);
if (failed())
return;
updateAggressivePurging(index);
Vector<size_t> framesToDecode;
size_t frameToDecode = index;
do {
framesToDecode.append(frameToDecode);
frameToDecode = m_frameBufferCache[frameToDecode].requiredPreviousFrameIndex();
} while (frameToDecode != kNotFound && m_frameBufferCache[frameToDecode].getStatus() != ImageFrame::FrameComplete);
for (auto i = framesToDecode.rbegin(); i != framesToDecode.rend(); ++i) {
if (!m_reader->decode(*i)) {
setFailed();
return;
}
if (m_purgeAggressively)
clearCacheExceptFrame(*i);
// We need more data to continue decoding.
if (m_frameBufferCache[*i].getStatus() != ImageFrame::FrameComplete)
break;
}
// It is also a fatal error if all data is received and we have decoded all
// frames available but the file is truncated.
if (index >= m_frameBufferCache.size() - 1 && isAllDataReceived() && m_reader && !m_reader->parseCompleted())
setFailed();
}
bool ImageDecoder::postDecodeProcessing(size_t index) {
DCHECK(index < m_frameBufferCache.size());
if (m_frameBufferCache[index].getStatus() != ImageFrame::FrameComplete)
return false;
if (m_purgeAggressively)
clearCacheExceptFrame(index);
return true;
}
void WEBPImageDecoder::decode(size_t index) {
if (failed())
return;
Vector<size_t> framesToDecode;
size_t frameToDecode = index;
do {
framesToDecode.append(frameToDecode);
frameToDecode =
m_frameBufferCache[frameToDecode].requiredPreviousFrameIndex();
} while (frameToDecode != kNotFound &&
m_frameBufferCache[frameToDecode].getStatus() !=
ImageFrame::FrameComplete);
ASSERT(m_demux);
for (auto i = framesToDecode.rbegin(); i != framesToDecode.rend(); ++i) {
if ((m_formatFlags & ANIMATION_FLAG) && !initFrameBuffer(*i))
return;
WebPIterator webpFrame;
if (!WebPDemuxGetFrame(m_demux, *i + 1, &webpFrame)) {
setFailed();
} else {
decodeSingleFrame(webpFrame.fragment.bytes, webpFrame.fragment.size, *i);
WebPDemuxReleaseIterator(&webpFrame);
}
if (failed())
return;
// We need more data to continue decoding.
if (m_frameBufferCache[*i].getStatus() != ImageFrame::FrameComplete)
break;
if (m_purgeAggressively)
clearCacheExceptFrame(*i);
}
// It is also a fatal error if all data is received and we have decoded all
// frames available but the file is truncated.
if (index >= m_frameBufferCache.size() - 1 && isAllDataReceived() &&
m_demux && m_demuxState != WEBP_DEMUX_DONE)
setFailed();
}
