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Diffstat (limited to 'image/Decoder.h')
| -rw-r--r-- | image/Decoder.h | 562 |
1 files changed, 562 insertions, 0 deletions
diff --git a/image/Decoder.h b/image/Decoder.h new file mode 100644 index 000000000..065a3c213 --- /dev/null +++ b/image/Decoder.h @@ -0,0 +1,562 @@ +/* -*- 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_Decoder_h +#define mozilla_image_Decoder_h + +#include "FrameAnimator.h" +#include "RasterImage.h" +#include "mozilla/Maybe.h" +#include "mozilla/NotNull.h" +#include "mozilla/RefPtr.h" +#include "DecodePool.h" +#include "DecoderFlags.h" +#include "Downscaler.h" +#include "ImageMetadata.h" +#include "Orientation.h" +#include "SourceBuffer.h" +#include "StreamingLexer.h" +#include "SurfaceFlags.h" + +namespace mozilla { + +namespace Telemetry { + enum ID : uint32_t; +} // namespace Telemetry + +namespace image { + +struct DecoderFinalStatus final +{ + DecoderFinalStatus(bool aWasMetadataDecode, + bool aFinished, + bool aHadError, + bool aShouldReportError) + : mWasMetadataDecode(aWasMetadataDecode) + , mFinished(aFinished) + , mHadError(aHadError) + , mShouldReportError(aShouldReportError) + { } + + /// True if this was a metadata decode. + const bool mWasMetadataDecode : 1; + + /// True if this decoder finished, whether successfully or due to failure. + const bool mFinished : 1; + + /// True if this decoder encountered an error. + const bool mHadError : 1; + + /// True if this decoder encountered the kind of error that should be reported + /// to the console. + const bool mShouldReportError : 1; +}; + +struct DecoderTelemetry final +{ + DecoderTelemetry(Maybe<Telemetry::ID> aSpeedHistogram, + size_t aBytesDecoded, + uint32_t aChunkCount, + TimeDuration aDecodeTime) + : mSpeedHistogram(aSpeedHistogram) + , mBytesDecoded(aBytesDecoded) + , mChunkCount(aChunkCount) + , mDecodeTime(aDecodeTime) + { } + + /// @return our decoder's speed, in KBps. + int32_t Speed() const + { + return mBytesDecoded / (1024 * mDecodeTime.ToSeconds()); + } + + /// @return our decoder's decode time, in microseconds. + int32_t DecodeTimeMicros() { return mDecodeTime.ToMicroseconds(); } + + /// The per-image-format telemetry ID for recording our decoder's speed, or + /// Nothing() if we don't record speed telemetry for this kind of decoder. + const Maybe<Telemetry::ID> mSpeedHistogram; + + /// The number of bytes of input our decoder processed. + const size_t mBytesDecoded; + + /// The number of chunks our decoder's input was divided into. + const uint32_t mChunkCount; + + /// The amount of time our decoder spent inside DoDecode(). + const TimeDuration mDecodeTime; +}; + +class Decoder +{ +public: + NS_INLINE_DECL_THREADSAFE_REFCOUNTING(Decoder) + + explicit Decoder(RasterImage* aImage); + + /** + * Initialize an image decoder. Decoders may not be re-initialized. + * + * @return NS_OK if the decoder could be initialized successfully. + */ + nsresult Init(); + + /** + * Decodes, reading all data currently available in the SourceBuffer. + * + * If more data is needed and @aOnResume is non-null, Decode() will schedule + * @aOnResume to be called when more data is available. + * + * @return a LexerResult which may indicate: + * - the image has been successfully decoded (TerminalState::SUCCESS), or + * - the image has failed to decode (TerminalState::FAILURE), or + * - the decoder is yielding until it gets more data (Yield::NEED_MORE_DATA), or + * - the decoder is yielding to allow the caller to access intermediate + * output (Yield::OUTPUT_AVAILABLE). + */ + LexerResult Decode(IResumable* aOnResume = nullptr); + + /** + * Terminate this decoder in a failure state, just as if the decoder + * implementation had returned TerminalState::FAILURE from DoDecode(). + * + * XXX(seth): This method should be removed ASAP; it exists only because + * RasterImage::FinalizeDecoder() requires an actual Decoder object as an + * argument, so we can't simply tell RasterImage a decode failed except via an + * intervening decoder. We'll fix this in bug 1291071. + */ + LexerResult TerminateFailure(); + + /** + * Given a maximum number of bytes we're willing to decode, @aByteLimit, + * returns true if we should attempt to run this decoder synchronously. + */ + bool ShouldSyncDecode(size_t aByteLimit); + + /** + * Gets the invalidation region accumulated by the decoder so far, and clears + * the decoder's invalidation region. This means that each call to + * TakeInvalidRect() returns only the invalidation region accumulated since + * the last call to TakeInvalidRect(). + */ + nsIntRect TakeInvalidRect() + { + nsIntRect invalidRect = mInvalidRect; + mInvalidRect.SetEmpty(); + return invalidRect; + } + + /** + * Gets the progress changes accumulated by the decoder so far, and clears + * them. This means that each call to TakeProgress() returns only the changes + * accumulated since the last call to TakeProgress(). + */ + Progress TakeProgress() + { + Progress progress = mProgress; + mProgress = NoProgress; + return progress; + } + + /** + * Returns true if there's any progress to report. + */ + bool HasProgress() const + { + return mProgress != NoProgress || !mInvalidRect.IsEmpty() || mFinishedNewFrame; + } + + /* + * State. + */ + + /** + * If we're doing a metadata decode, we only decode the image's headers, which + * is enough to determine the image's intrinsic size. A metadata decode is + * enabled by calling SetMetadataDecode() *before* calling Init(). + */ + void SetMetadataDecode(bool aMetadataDecode) + { + MOZ_ASSERT(!mInitialized, "Shouldn't be initialized yet"); + mMetadataDecode = aMetadataDecode; + } + bool IsMetadataDecode() const { return mMetadataDecode; } + + /** + * Sets the output size of this decoder. If this is smaller than the intrinsic + * size of the image, we'll downscale it while decoding. For memory usage + * reasons, upscaling is forbidden and will trigger assertions in debug + * builds. + * + * Not calling SetOutputSize() means that we should just decode at the + * intrinsic size, whatever it is. + * + * If SetOutputSize() was called, ExplicitOutputSize() can be used to + * determine the value that was passed to it. + * + * This must be called before Init() is called. + */ + void SetOutputSize(const gfx::IntSize& aSize); + + /** + * @return the output size of this decoder. If this is smaller than the + * intrinsic size, then the image will be downscaled during the decoding + * process. + * + * Illegal to call if HasSize() returns false. + */ + gfx::IntSize OutputSize() const { MOZ_ASSERT(HasSize()); return *mOutputSize; } + + /** + * @return either the size passed to SetOutputSize() or Nothing(), indicating + * that SetOutputSize() was not explicitly called. + */ + Maybe<gfx::IntSize> ExplicitOutputSize() const; + + /** + * Set the requested sample size for this decoder. Used to implement the + * -moz-sample-size media fragment. + * + * XXX(seth): Support for -moz-sample-size will be removed in bug 1120056. + */ + virtual void SetSampleSize(int aSampleSize) { } + + /** + * Set an iterator to the SourceBuffer which will feed data to this decoder. + * This must always be called before calling Init(). (And only before Init().) + * + * XXX(seth): We should eliminate this method and pass a SourceBufferIterator + * to the various decoder constructors instead. + */ + void SetIterator(SourceBufferIterator&& aIterator) + { + MOZ_ASSERT(!mInitialized, "Shouldn't be initialized yet"); + mIterator.emplace(Move(aIterator)); + } + + /** + * Should this decoder send partial invalidations? + */ + bool ShouldSendPartialInvalidations() const + { + return !(mDecoderFlags & DecoderFlags::IS_REDECODE); + } + + /** + * Should we stop decoding after the first frame? + */ + bool IsFirstFrameDecode() const + { + return bool(mDecoderFlags & DecoderFlags::FIRST_FRAME_ONLY); + } + + /** + * @return the number of complete animation frames which have been decoded so + * far, if it has changed since the last call to TakeCompleteFrameCount(); + * otherwise, returns Nothing(). + */ + Maybe<uint32_t> TakeCompleteFrameCount(); + + // The number of frames we have, including anything in-progress. Thus, this + // is only 0 if we haven't begun any frames. + uint32_t GetFrameCount() { return mFrameCount; } + + // Did we discover that the image we're decoding is animated? + bool HasAnimation() const { return mImageMetadata.HasAnimation(); } + + // Error tracking + bool HasError() const { return mError; } + bool ShouldReportError() const { return mShouldReportError; } + + /// Did we finish decoding enough that calling Decode() again would be useless? + bool GetDecodeDone() const + { + return mReachedTerminalState || mDecodeDone || + (mMetadataDecode && HasSize()) || HasError(); + } + + /// Are we in the middle of a frame right now? Used for assertions only. + bool InFrame() const { return mInFrame; } + + enum DecodeStyle { + PROGRESSIVE, // produce intermediate frames representing the partial + // state of the image + SEQUENTIAL // decode to final image immediately + }; + + /** + * Get or set the DecoderFlags that influence the behavior of this decoder. + */ + void SetDecoderFlags(DecoderFlags aDecoderFlags) + { + MOZ_ASSERT(!mInitialized); + mDecoderFlags = aDecoderFlags; + } + DecoderFlags GetDecoderFlags() const { return mDecoderFlags; } + + /** + * Get or set the SurfaceFlags that select the kind of output this decoder + * will produce. + */ + void SetSurfaceFlags(SurfaceFlags aSurfaceFlags) + { + MOZ_ASSERT(!mInitialized); + mSurfaceFlags = aSurfaceFlags; + } + SurfaceFlags GetSurfaceFlags() const { return mSurfaceFlags; } + + /// @return true if we know the intrinsic size of the image we're decoding. + bool HasSize() const { return mImageMetadata.HasSize(); } + + /** + * @return the intrinsic size of the image we're decoding. + * + * Illegal to call if HasSize() returns false. + */ + gfx::IntSize Size() const + { + MOZ_ASSERT(HasSize()); + return mImageMetadata.GetSize(); + } + + /** + * @return an IntRect which covers the entire area of this image at its + * intrinsic size, appropriate for use as a frame rect when the image itself + * does not specify one. + * + * Illegal to call if HasSize() returns false. + */ + gfx::IntRect FullFrame() const + { + return gfx::IntRect(gfx::IntPoint(), Size()); + } + + /** + * @return an IntRect which covers the entire area of this image at its size + * after scaling - that is, at its output size. + * + * XXX(seth): This is only used for decoders which are using the old + * Downscaler code instead of SurfacePipe, since the old AllocateFrame() and + * Downscaler APIs required that the frame rect be specified in output space. + * We should remove this once all decoders use SurfacePipe. + * + * Illegal to call if HasSize() returns false. + */ + gfx::IntRect FullOutputFrame() const + { + return gfx::IntRect(gfx::IntPoint(), OutputSize()); + } + + /// @return final status information about this decoder. Should be called + /// after we decide we're not going to run the decoder anymore. + DecoderFinalStatus FinalStatus() const; + + /// @return the metadata we collected about this image while decoding. + const ImageMetadata& GetImageMetadata() { return mImageMetadata; } + + /// @return performance telemetry we collected while decoding. + DecoderTelemetry Telemetry() const; + + /** + * @return a weak pointer to the image associated with this decoder. Illegal + * to call if this decoder is not associated with an image. + */ + NotNull<RasterImage*> GetImage() const { return WrapNotNull(mImage.get()); } + + /** + * @return a possibly-null weak pointer to the image associated with this + * decoder. May be called even if this decoder is not associated with an + * image. + */ + RasterImage* GetImageMaybeNull() const { return mImage.get(); } + + RawAccessFrameRef GetCurrentFrameRef() + { + return mCurrentFrame ? mCurrentFrame->RawAccessRef() + : RawAccessFrameRef(); + } + + +protected: + friend class AutoRecordDecoderTelemetry; + friend class nsICODecoder; + friend class PalettedSurfaceSink; + friend class SurfaceSink; + + virtual ~Decoder(); + + /* + * Internal hooks. Decoder implementations may override these and + * only these methods. + * + * BeforeFinishInternal() can be used to detect if decoding is in an + * incomplete state, e.g. due to file truncation, in which case it should + * return a failing nsresult. + */ + virtual nsresult InitInternal(); + virtual LexerResult DoDecode(SourceBufferIterator& aIterator, + IResumable* aOnResume) = 0; + virtual nsresult BeforeFinishInternal(); + virtual nsresult FinishInternal(); + virtual nsresult FinishWithErrorInternal(); + + /** + * @return the per-image-format telemetry ID for recording this decoder's + * speed, or Nothing() if we don't record speed telemetry for this kind of + * decoder. + */ + virtual Maybe<Telemetry::ID> SpeedHistogram() const { return Nothing(); } + + + /* + * Progress notifications. + */ + + // Called by decoders when they determine the size of the image. Informs + // the image of its size and sends notifications. + void PostSize(int32_t aWidth, + int32_t aHeight, + Orientation aOrientation = Orientation()); + + // Called by decoders if they determine that the image has transparency. + // + // This should be fired as early as possible to allow observers to do things + // that affect content, so it's necessarily pessimistic - if there's a + // possibility that the image has transparency, for example because its header + // specifies that it has an alpha channel, we fire PostHasTransparency + // immediately. PostFrameStop's aFrameOpacity argument, on the other hand, is + // only used internally to ImageLib. Because PostFrameStop isn't delivered + // until the entire frame has been decoded, decoders may take into account the + // actual contents of the frame and give a more accurate result. + void PostHasTransparency(); + + // Called by decoders if they determine that the image is animated. + // + // @param aTimeout The time for which the first frame should be shown before + // we advance to the next frame. + void PostIsAnimated(FrameTimeout aFirstFrameTimeout); + + // Called by decoders when they end a frame. Informs the image, sends + // notifications, and does internal book-keeping. + // Specify whether this frame is opaque as an optimization. + // For animated images, specify the disposal, blend method and timeout for + // this frame. + void PostFrameStop(Opacity aFrameOpacity = Opacity::SOME_TRANSPARENCY, + DisposalMethod aDisposalMethod = DisposalMethod::KEEP, + FrameTimeout aTimeout = FrameTimeout::Forever(), + BlendMethod aBlendMethod = BlendMethod::OVER, + const Maybe<nsIntRect>& aBlendRect = Nothing()); + + /** + * Called by the decoders when they have a region to invalidate. We may not + * actually pass these invalidations on right away. + * + * @param aRect The invalidation rect in the coordinate system of the unscaled + * image (that is, the image at its intrinsic size). + * @param aRectAtOutputSize If not Nothing(), the invalidation rect in the + * coordinate system of the scaled image (that is, + * the image at our output size). This must + * be supplied if we're downscaling during decode. + */ + void PostInvalidation(const gfx::IntRect& aRect, + const Maybe<gfx::IntRect>& aRectAtOutputSize = Nothing()); + + // Called by the decoders when they have successfully decoded the image. This + // may occur as the result of the decoder getting to the appropriate point in + // the stream, or by us calling FinishInternal(). + // + // May not be called mid-frame. + // + // For animated images, specify the loop count. -1 means loop forever, 0 + // means a single iteration, stopping on the last frame. + void PostDecodeDone(int32_t aLoopCount = 0); + + /** + * Allocates a new frame, making it our current frame if successful. + * + * The @aFrameNum parameter only exists as a sanity check; it's illegal to + * create a new frame anywhere but immediately after the existing frames. + * + * If a non-paletted frame is desired, pass 0 for aPaletteDepth. + */ + nsresult AllocateFrame(uint32_t aFrameNum, + const gfx::IntSize& aOutputSize, + const gfx::IntRect& aFrameRect, + gfx::SurfaceFormat aFormat, + uint8_t aPaletteDepth = 0); + +private: + /// Report that an error was encountered while decoding. + void PostError(); + + /** + * CompleteDecode() finishes up the decoding process after Decode() determines + * that we're finished. It records final progress and does all the cleanup + * that's possible off-main-thread. + */ + void CompleteDecode(); + + /// @return the number of complete frames we have. Does not include the + /// current frame if it's unfinished. + uint32_t GetCompleteFrameCount() + { + if (mFrameCount == 0) { + return 0; + } + + return mInFrame ? mFrameCount - 1 : mFrameCount; + } + + RawAccessFrameRef AllocateFrameInternal(uint32_t aFrameNum, + const gfx::IntSize& aOutputSize, + const gfx::IntRect& aFrameRect, + gfx::SurfaceFormat aFormat, + uint8_t aPaletteDepth, + imgFrame* aPreviousFrame); + +protected: + Maybe<Downscaler> mDownscaler; + + uint8_t* mImageData; // Pointer to image data in either Cairo or 8bit format + uint32_t mImageDataLength; + uint32_t* mColormap; // Current colormap to be used in Cairo format + uint32_t mColormapSize; + +private: + RefPtr<RasterImage> mImage; + Maybe<SourceBufferIterator> mIterator; + RawAccessFrameRef mCurrentFrame; + ImageMetadata mImageMetadata; + gfx::IntRect mInvalidRect; // Tracks an invalidation region in the current frame. + Maybe<gfx::IntSize> mOutputSize; // The size of our output surface. + Progress mProgress; + + uint32_t mFrameCount; // Number of frames, including anything in-progress + FrameTimeout mLoopLength; // Length of a single loop of this image. + gfx::IntRect mFirstFrameRefreshArea; // The area of the image that needs to + // be invalidated when the animation loops. + + // Telemetry data for this decoder. + TimeDuration mDecodeTime; + + DecoderFlags mDecoderFlags; + SurfaceFlags mSurfaceFlags; + + bool mInitialized : 1; + bool mMetadataDecode : 1; + bool mHaveExplicitOutputSize : 1; + bool mInFrame : 1; + bool mFinishedNewFrame : 1; // True if PostFrameStop() has been called since + // the last call to TakeCompleteFrameCount(). + bool mReachedTerminalState : 1; + bool mDecodeDone : 1; + bool mError : 1; + bool mShouldReportError : 1; +}; + +} // namespace image +} // namespace mozilla + +#endif // mozilla_image_Decoder_h |