gecko-dev/image/decoders/nsWebPDecoder.h

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef mozilla_image_decoders_nsWebPDecoder_h
#define mozilla_image_decoders_nsWebPDecoder_h
#include "Decoder.h"
#include "webp/demux.h"
#include "StreamingLexer.h"
#include "SurfacePipe.h"
namespace mozilla {
namespace image {
class RasterImage;
class nsWebPDecoder final : public Decoder {
public:
virtual ~nsWebPDecoder();
DecoderType GetType() const override { return DecoderType::WEBP; }
protected:
LexerResult DoDecode(SourceBufferIterator& aIterator,
IResumable* aOnResume) override;
Maybe<Telemetry::HistogramID> SpeedHistogram() const override;
private:
friend class DecoderFactory;
// Decoders should only be instantiated via DecoderFactory.
explicit nsWebPDecoder(RasterImage* aImage);
void ApplyColorProfile(const char* aProfile, size_t aLength);
LexerResult UpdateBuffer(SourceBufferIterator& aIterator,
SourceBufferIterator::State aState);
LexerResult ReadData();
LexerResult ReadHeader(WebPDemuxer* aDemuxer, bool aIsComplete);
LexerResult ReadPayload(WebPDemuxer* aDemuxer, bool aIsComplete);
nsresult CreateFrame(const nsIntRect& aFrameRect);
void EndFrame();
LexerResult ReadSingle(const uint8_t* aData, size_t aLength,
const gfx::IntRect& aFrameRect);
LexerResult ReadMultiple(WebPDemuxer* aDemuxer, bool aIsComplete);
/// The SurfacePipe used to write to the output surface.
SurfacePipe mPipe;
/// The buffer used to accumulate data until the complete WebP header is
/// received, if and only if the iterator is discontiguous.
Vector<uint8_t> mBufferedData;
/// The libwebp output buffer descriptor pointing to the decoded data.
WebPDecBuffer mBuffer;
/// The libwebp incremental decoder descriptor, wraps mBuffer.
WebPIDecoder* mDecoder;
/// Blend method for the current frame.
BlendMethod mBlend;
/// Disposal method for the current frame.
DisposalMethod mDisposal;
/// Frame timeout for the current frame;
FrameTimeout mTimeout;
/// Surface format for the current frame.
gfx::SurfaceFormat mFormat;
/// Frame rect for the current frame.
gfx::IntRect mFrameRect;
/// The last row of decoded pixels written to mPipe.
int mLastRow;
/// Number of decoded frames.
uint32_t mCurrentFrame;
/// Pointer to the start of the contiguous encoded image data.
const uint8_t* mData;
/// Length of data pointed to by mData.
size_t mLength;
/// True if the iterator has reached its end.
bool mIteratorComplete;
/// True if this decoding pass requires a WebPDemuxer.
bool mNeedDemuxer;
/// True if we have setup the color profile for the image.
bool mGotColorProfile;
};
} // namespace image
} // namespace mozilla
#endif // mozilla_image_decoders_nsWebPDecoder_h