Decoder::Decoder(RasterImage* aImage)
: mImageData(nullptr)
, mImageDataLength(0)
, mColormap(nullptr)
, mColormapSize(0)
, mImage(aImage)
, mProgress(NoProgress)
, mFrameCount(0)
, mFailCode(NS_OK)
, mChunkCount(0)
, mDecoderFlags(DefaultDecoderFlags())
, mSurfaceFlags(DefaultSurfaceFlags())
, mBytesDecoded(0)
, mInitialized(false)
, mMetadataDecode(false)
, mInFrame(false)
, mDataDone(false)
, mDecodeDone(false)
, mDataError(false)
, mDecodeAborted(false)
, mShouldReportError(false)
{ }
NS_IMETHODIMP
RasterImage::Decode(const IntSize& aSize,
uint32_t aFlags,
PlaybackType aPlaybackType)
{
MOZ_ASSERT(NS_IsMainThread());
if (mError) {
return NS_ERROR_FAILURE;
}
// If we don't have a size yet, we can't do any other decoding.
if (!mHasSize) {
mWantFullDecode = true;
return NS_OK;
}
// We're about to decode again, which may mean that some of the previous sizes
// we've decoded at aren't useful anymore. We can allow them to expire from
// the cache by unlocking them here. When the decode finishes, it will send an
// invalidation that will cause all instances of this image to redraw. If this
// image is locked, any surfaces that are still useful will become locked
// again when LookupFrame touches them, and the remainder will eventually
// expire.
SurfaceCache::UnlockEntries(ImageKey(this));
// Determine which flags we need to decode this image with.
DecoderFlags decoderFlags = DefaultDecoderFlags();
if (aFlags & FLAG_ASYNC_NOTIFY) {
decoderFlags |= DecoderFlags::ASYNC_NOTIFY;
}
if (mTransient) {
decoderFlags |= DecoderFlags::IMAGE_IS_TRANSIENT;
}
if (mHasBeenDecoded) {
decoderFlags |= DecoderFlags::IS_REDECODE;
}
SurfaceFlags surfaceFlags = ToSurfaceFlags(aFlags);
if (IsOpaque()) {
// If there's no transparency, it doesn't matter whether we premultiply
// alpha or not.
surfaceFlags &= ~SurfaceFlags::NO_PREMULTIPLY_ALPHA;
}
// Create a decoder.
RefPtr<IDecodingTask> task;
if (mAnimationState && aPlaybackType == PlaybackType::eAnimated) {
task = DecoderFactory::CreateAnimationDecoder(mDecoderType, WrapNotNull(this),
mSourceBuffer, mSize,
decoderFlags, surfaceFlags);
} else {
task = DecoderFactory::CreateDecoder(mDecoderType, WrapNotNull(this),
mSourceBuffer, mSize, aSize,
decoderFlags, surfaceFlags,
mRequestedSampleSize);
}
// Make sure DecoderFactory was able to create a decoder successfully.
if (!task) {
return NS_ERROR_FAILURE;
}
mDecodeCount++;
// We're ready to decode; start the decoder.
LaunchDecodingTask(task, this, aFlags, mHasSourceData);
return NS_OK;
}
