sk_sp<SkImage> DeferredImageDecoder::createFrameAtIndex(size_t index) {
if (m_frameGenerator && m_frameGenerator->decodeFailed())
return nullptr;
prepareLazyDecodedFrames();
if (index < m_frameData.size()) {
DeferredFrameData* frameData = &m_frameData[index];
if (m_actualDecoder)
frameData->m_frameBytes = m_actualDecoder->frameBytesAtIndex(index);
else
frameData->m_frameBytes = m_size.area() * sizeof(ImageFrame::PixelData);
// ImageFrameGenerator has the latest known alpha state. There will be a
// performance boost if this frame is opaque.
DCHECK(m_frameGenerator);
return createFrameImageAtIndex(index, !m_frameGenerator->hasAlpha(index));
}
if (!m_actualDecoder || m_actualDecoder->failed())
return nullptr;
ImageFrame* frame = m_actualDecoder->frameBufferAtIndex(index);
if (!frame || frame->getStatus() == ImageFrame::FrameEmpty)
return nullptr;
return (frame->getStatus() == ImageFrame::FrameComplete)
? frame->finalizePixelsAndGetImage()
: SkImage::MakeFromBitmap(frame->bitmap());
}
