The Tor Browser: comparison content/media/encoder/TrackEncoder.h

--1:000000000000
+:dd14b73fc7cc
+/* -*- 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 TrackEncoder_h_
+#define TrackEncoder_h_
+#include "mozilla/ReentrantMonitor.h"
+#include "AudioSegment.h"
+#include "EncodedFrameContainer.h"
+#include "StreamBuffer.h"
+#include "TrackMetadataBase.h"
+#include "VideoSegment.h"
+namespace mozilla {
+class MediaStreamGraph;
+/**
+* Base class of AudioTrackEncoder and VideoTrackEncoder. Lifetimes managed by
+* MediaEncoder. Most methods can only be called on the MediaEncoder's thread,
+* but some subclass methods can be called on other threads when noted.
+*
+* NotifyQueuedTrackChanges is called on subclasses of this class from the
+* MediaStreamGraph thread, and AppendAudioSegment/AppendVideoSegment is then
+* called to store media data in the TrackEncoder. Later on, GetEncodedTrack is
+* called on MediaEncoder's thread to encode and retrieve the encoded data.
+*/
+class TrackEncoder
+{
+public:
+TrackEncoder();
+virtual ~TrackEncoder() {}
+/**
+* Notified by the same callbcak of MediaEncoder when it has received a track
+* change from MediaStreamGraph. Called on the MediaStreamGraph thread.
+*/
+virtual void NotifyQueuedTrackChanges(MediaStreamGraph* aGraph, TrackID aID,
+TrackRate aTrackRate,
+TrackTicks aTrackOffset,
+uint32_t aTrackEvents,
+const MediaSegment& aQueuedMedia) = 0;
+/**
+* Notified by the same callback of MediaEncoder when it has been removed from
+* MediaStreamGraph. Called on the MediaStreamGraph thread.
+*/
+void NotifyRemoved(MediaStreamGraph* aGraph) { NotifyEndOfStream(); }
+/**
+* Creates and sets up meta data for a specific codec, called on the worker
+* thread.
+*/
+virtual already_AddRefed<TrackMetadataBase> GetMetadata() = 0;
+/**
+* Encodes raw segments. Result data is returned in aData, and called on the
+* worker thread.
+*/
+virtual nsresult GetEncodedTrack(EncodedFrameContainer& aData) = 0;
+/**
+* True if the track encoder has encoded all source segments coming from
+* MediaStreamGraph. Call on the worker thread.
+*/
+bool IsEncodingComplete() { return mEncodingComplete; }
+/**
+* Notifies from MediaEncoder to cancel the encoding, and wakes up
+* mReentrantMonitor if encoder is waiting on it.
+*/
+void NotifyCancel()
+{
+ReentrantMonitorAutoEnter mon(mReentrantMonitor);
+mCanceled = true;
+mReentrantMonitor.NotifyAll();
+}
+protected:
+/**
+* Notifies track encoder that we have reached the end of source stream, and
+* wakes up mReentrantMonitor if encoder is waiting for any source data.
+*/
+virtual void NotifyEndOfStream() = 0;
+/**
+* A ReentrantMonitor to protect the pushing and pulling of mRawSegment which
+* is declared in its subclasses, and the following flags: mInitialized,
+* EndOfStream and mCanceled. The control of protection is managed by its
+* subclasses.
+*/
+ReentrantMonitor mReentrantMonitor;
+/**
+* True if the track encoder has encoded all source data.
+*/
+bool mEncodingComplete;
+/**
+* True if flag of EOS or any form of indicating EOS has set in the codec-
+* encoder.
+*/
+bool mEosSetInEncoder;
+/**
+* True if the track encoder has initialized successfully, protected by
+* mReentrantMonitor.
+*/
+bool mInitialized;
+/**
+* True if the TrackEncoder has received an event of TRACK_EVENT_ENDED from
+* MediaStreamGraph, or the MediaEncoder is removed from its source stream,
+* protected by mReentrantMonitor.
+*/
+bool mEndOfStream;
+/**
+* True if a cancellation of encoding is sent from MediaEncoder, protected by
+* mReentrantMonitor.
+*/
+bool mCanceled;
+#ifdef PR_LOGGING
+// How many times we have tried to initialize the encoder.
+uint32_t mAudioInitCounter;
+uint32_t mVideoInitCounter;
+#endif
+};
+class AudioTrackEncoder : public TrackEncoder
+{
+public:
+AudioTrackEncoder()
+: TrackEncoder()
+, mChannels(0)
+, mSamplingRate(0)
+{}
+void NotifyQueuedTrackChanges(MediaStreamGraph* aGraph, TrackID aID,
+TrackRate aTrackRate,
+TrackTicks aTrackOffset,
+uint32_t aTrackEvents,
+const MediaSegment& aQueuedMedia) MOZ_OVERRIDE;
+/**
+* Interleaves the track data and stores the result into aOutput. Might need
+* to up-mix or down-mix the channel data if the channels number of this chunk
+* is different from aOutputChannels. The channel data from aChunk might be
+* modified by up-mixing.
+*/
+static void InterleaveTrackData(AudioChunk& aChunk, int32_t aDuration,
+uint32_t aOutputChannels,
+AudioDataValue* aOutput);
+/**
+* De-interleaves the aInput data and stores the result into aOutput.
+* No up-mix or down-mix operations inside.
+*/
+static void DeInterleaveTrackData(AudioDataValue* aInput, int32_t aDuration,
+int32_t aChannels, AudioDataValue* aOutput);
+protected:
+/**
+* Number of samples per channel in a pcm buffer. This is also the value of
+* frame size required by audio encoder, and mReentrantMonitor will be
+* notified when at least this much data has been added to mRawSegment.
+*/
+virtual int GetPacketDuration() { return 0; }
+/**
+* Initializes the audio encoder. The call of this method is delayed until we
+* have received the first valid track from MediaStreamGraph, and the
+* mReentrantMonitor will be notified if other methods is waiting for encoder
+* to be completely initialized. This method is called on the MediaStreamGraph
+* thread.
+*/
+virtual nsresult Init(int aChannels, int aSamplingRate) = 0;
+/**
+* Appends and consumes track data from aSegment, this method is called on
+* the MediaStreamGraph thread. mReentrantMonitor will be notified when at
+* least GetPacketDuration() data has been added to mRawSegment, wake up other
+* method which is waiting for more data from mRawSegment.
+*/
+nsresult AppendAudioSegment(const AudioSegment& aSegment);
+/**
+* Notifies the audio encoder that we have reached the end of source stream,
+* and wakes up mReentrantMonitor if encoder is waiting for more track data.
+*/
+virtual void NotifyEndOfStream() MOZ_OVERRIDE;
+/**
+* The number of channels are used for processing PCM data in the audio encoder.
+* This value comes from the first valid audio chunk. If encoder can't support
+* the channels in the chunk, downmix PCM stream can be performed.
+* This value also be used to initialize the audio encoder.
+*/
+int mChannels;
+/**
+* The sampling rate of source audio data.
+*/
+int mSamplingRate;
+/**
+* A segment queue of audio track data, protected by mReentrantMonitor.
+*/
+AudioSegment mRawSegment;
+};
+class VideoTrackEncoder : public TrackEncoder
+{
+public:
+VideoTrackEncoder()
+: TrackEncoder()
+, mFrameWidth(0)
+, mFrameHeight(0)
+, mDisplayWidth(0)
+, mDisplayHeight(0)
+, mTrackRate(0)
+, mTotalFrameDuration(0)
+{}
+/**
+* Notified by the same callbcak of MediaEncoder when it has received a track
+* change from MediaStreamGraph. Called on the MediaStreamGraph thread.
+*/
+void NotifyQueuedTrackChanges(MediaStreamGraph* aGraph, TrackID aID,
+TrackRate aTrackRate,
+TrackTicks aTrackOffset,
+uint32_t aTrackEvents,
+const MediaSegment& aQueuedMedia) MOZ_OVERRIDE;
+protected:
+/**
+* Initialized the video encoder. In order to collect the value of width and
+* height of source frames, this initialization is delayed until we have
+* received the first valid video frame from MediaStreamGraph;
+* mReentrantMonitor will be notified after it has successfully initialized,
+* and this method is called on the MediaStramGraph thread.
+*/
+virtual nsresult Init(int aWidth, int aHeight, int aDisplayWidth,
+int aDisplayHeight, TrackRate aTrackRate) = 0;
+/**
+* Appends source video frames to mRawSegment. We only append the source chunk
+* if it is unique to mLastChunk. Called on the MediaStreamGraph thread.
+*/
+nsresult AppendVideoSegment(const VideoSegment& aSegment);
+/**
+* Tells the video track encoder that we've reached the end of source stream,
+* and wakes up mReentrantMonitor if encoder is waiting for more track data.
+* Called on the MediaStreamGraph thread.
+*/
+virtual void NotifyEndOfStream() MOZ_OVERRIDE;
+/**
+* Create a buffer of black image in format of YUV:420. Called on the worker
+* thread.
+*/
+void CreateMutedFrame(nsTArray<uint8_t>* aOutputBuffer);
+/**
+* The width of source video frame, ceiled if the source width is odd.
+*/
+int mFrameWidth;
+/**
+* The height of source video frame, ceiled if the source height is odd.
+*/
+int mFrameHeight;
+/**
+* The display width of source video frame.
+*/
+int mDisplayWidth;
+/**
+* The display height of source video frame.
+*/
+int mDisplayHeight;
+/**
+* The track rate of source video.
+*/
+TrackRate mTrackRate;
+/**
+* The total duration of frames in encoded video in TrackTicks, kept track of
+* in subclasses.
+*/
+TrackTicks mTotalFrameDuration;
+/**
+* The last unique frame we've sent to track encoder, kept track of in
+* subclasses.
+*/
+VideoFrame mLastFrame;
+/**
+* A segment queue of audio track data, protected by mReentrantMonitor.
+*/
+VideoSegment mRawSegment;
+};
+}
+#endif

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comparison: content/media/encoder/TrackEncoder.h

content/media/encoder/TrackEncoder.h