1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/content/media/encoder/MediaEncoder.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,164 @@
1.4 +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-*/
1.5 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this file,
1.7 + * You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +#ifndef MediaEncoder_h_
1.10 +#define MediaEncoder_h_
1.11 +
1.12 +#include "mozilla/DebugOnly.h"
1.13 +#include "TrackEncoder.h"
1.14 +#include "ContainerWriter.h"
1.15 +#include "MediaStreamGraph.h"
1.16 +
1.17 +namespace mozilla {
1.18 +
1.19 +/**
1.20 + * MediaEncoder is the framework of encoding module, it controls and manages
1.21 + * procedures between ContainerWriter and TrackEncoder. ContainerWriter packs
1.22 + * the encoded track data with a specific container (e.g. ogg, mp4).
1.23 + * AudioTrackEncoder and VideoTrackEncoder are subclasses of TrackEncoder, and
1.24 + * are responsible for encoding raw data coming from MediaStreamGraph.
1.25 + *
1.26 + * Also, MediaEncoder is a type of MediaStreamListener, it starts to receive raw
1.27 + * segments after itself is added to the source stream. In the mean time,
1.28 + * encoded track data is pulled by its owner periodically on a worker thread. A
1.29 + * reentrant monitor is used to protect the push and pull of resource.
1.30 + *
1.31 + * MediaEncoder is designed to be a passive component, neither it owns nor in
1.32 + * charge of managing threads. However, a monitor is used in function
1.33 + * TrackEncoder::GetEncodedTrack() for the purpose of thread safety (e.g.
1.34 + * between callbacks of MediaStreamListener and others), a call to this function
1.35 + * might block. Therefore, MediaEncoder should not run on threads that forbid
1.36 + * blocking, such as main thread or I/O thread.
1.37 + *
1.38 + * For example, an usage from MediaRecorder of this component would be:
1.39 + * 1) Create an encoder with a valid MIME type.
1.40 + * => encoder = MediaEncoder::CreateEncoder(aMIMEType);
1.41 + * It then generate a ContainerWriter according to the MIME type, and an
1.42 + * AudioTrackEncoder (or a VideoTrackEncoder too) associated with the media
1.43 + * type.
1.44 + *
1.45 + * 2) Dispatch the task GetEncodedData() to a worker thread.
1.46 + *
1.47 + * 3) To start encoding, add this component to its source stream.
1.48 + * => sourceStream->AddListener(encoder);
1.49 + *
1.50 + * 4) To stop encoding, remove this component from its source stream.
1.51 + * => sourceStream->RemoveListener(encoder);
1.52 + */
1.53 +class MediaEncoder : public MediaStreamListener
1.54 +{
1.55 +public :
1.56 + enum {
1.57 + ENCODE_METADDATA,
1.58 + ENCODE_TRACK,
1.59 + ENCODE_DONE,
1.60 + ENCODE_ERROR,
1.61 + };
1.62 +
1.63 + MediaEncoder(ContainerWriter* aWriter,
1.64 + AudioTrackEncoder* aAudioEncoder,
1.65 + VideoTrackEncoder* aVideoEncoder,
1.66 + const nsAString& aMIMEType)
1.67 + : mWriter(aWriter)
1.68 + , mAudioEncoder(aAudioEncoder)
1.69 + , mVideoEncoder(aVideoEncoder)
1.70 + , mStartTime(TimeStamp::Now())
1.71 + , mMIMEType(aMIMEType)
1.72 + , mState(MediaEncoder::ENCODE_METADDATA)
1.73 + , mShutdown(false)
1.74 + {}
1.75 +
1.76 + ~MediaEncoder() {};
1.77 +
1.78 + /**
1.79 + * Notified by the control loop of MediaStreamGraph; aQueueMedia is the raw
1.80 + * track data in form of MediaSegment.
1.81 + */
1.82 + virtual void NotifyQueuedTrackChanges(MediaStreamGraph* aGraph, TrackID aID,
1.83 + TrackRate aTrackRate,
1.84 + TrackTicks aTrackOffset,
1.85 + uint32_t aTrackEvents,
1.86 + const MediaSegment& aQueuedMedia);
1.87 +
1.88 + /**
1.89 + * Notified the stream is being removed.
1.90 + */
1.91 + virtual void NotifyRemoved(MediaStreamGraph* aGraph);
1.92 +
1.93 + /**
1.94 + * Creates an encoder with a given MIME type. Returns null if we are unable
1.95 + * to create the encoder. For now, default aMIMEType to "audio/ogg" and use
1.96 + * Ogg+Opus if it is empty.
1.97 + */
1.98 + static already_AddRefed<MediaEncoder> CreateEncoder(const nsAString& aMIMEType,
1.99 + uint8_t aTrackTypes = ContainerWriter::CREATE_AUDIO_TRACK);
1.100 + /**
1.101 + * Encodes the raw track data and returns the final container data. Assuming
1.102 + * it is called on a single worker thread. The buffer of container data is
1.103 + * allocated in ContainerWriter::GetContainerData(), and is appended to
1.104 + * aOutputBufs. aMIMEType is the valid mime-type of this returned container
1.105 + * data.
1.106 + */
1.107 + void GetEncodedData(nsTArray<nsTArray<uint8_t> >* aOutputBufs,
1.108 + nsAString& aMIMEType);
1.109 +
1.110 + /**
1.111 + * Return true if MediaEncoder has been shutdown. Reasons are encoding
1.112 + * complete, encounter an error, or being canceled by its caller.
1.113 + */
1.114 + bool IsShutdown()
1.115 + {
1.116 + return mShutdown;
1.117 + }
1.118 +
1.119 + /**
1.120 + * Cancel the encoding, and wakes up the lock of reentrant monitor in encoder.
1.121 + */
1.122 + void Cancel()
1.123 + {
1.124 + if (mAudioEncoder) {
1.125 + mAudioEncoder->NotifyCancel();
1.126 + }
1.127 + if (mVideoEncoder) {
1.128 + mVideoEncoder->NotifyCancel();
1.129 + }
1.130 + }
1.131 +
1.132 + bool HasError()
1.133 + {
1.134 + return mState == ENCODE_ERROR;
1.135 + }
1.136 +
1.137 +#ifdef MOZ_WEBM_ENCODER
1.138 + static bool IsWebMEncoderEnabled();
1.139 +#endif
1.140 +
1.141 +#ifdef MOZ_OMX_ENCODER
1.142 + static bool IsOMXEncoderEnabled();
1.143 +#endif
1.144 +
1.145 +private:
1.146 + // Get encoded data from trackEncoder and write to muxer
1.147 + nsresult WriteEncodedDataToMuxer(TrackEncoder *aTrackEncoder);
1.148 + // Get metadata from trackEncoder and copy to muxer
1.149 + nsresult CopyMetadataToMuxer(TrackEncoder* aTrackEncoder);
1.150 + nsAutoPtr<ContainerWriter> mWriter;
1.151 + nsAutoPtr<AudioTrackEncoder> mAudioEncoder;
1.152 + nsAutoPtr<VideoTrackEncoder> mVideoEncoder;
1.153 + TimeStamp mStartTime;
1.154 + nsString mMIMEType;
1.155 + int mState;
1.156 + bool mShutdown;
1.157 + // Get duration from create encoder, for logging purpose
1.158 + double GetEncodeTimeStamp()
1.159 + {
1.160 + TimeDuration decodeTime;
1.161 + decodeTime = TimeStamp::Now() - mStartTime;
1.162 + return decodeTime.ToMilliseconds();
1.163 + }
1.164 +};
1.165 +
1.166 +}
1.167 +#endif
