loadingLibStageFright主要工作流程
videoDecode
1创建playerengine
// 设置数据源，以及 audio sink
MediaPlayer::SetDataSource(PATH_TO_FILE)-> MediaPlayerService::create->
MediaPlayerService::Client::setDataSource-> MediaPlayerService:: Client:: GetPlayerType-> MediaPlayerService:: Client::CreatePlayer-> StagefrightPlayer:: setAudioSink-> StagefrightPlayer:: setDataSource->
Create MediaPlayerImpl（AwesomePlayer）-> MediaPlayerImpl:: MediaPlayerImpl PlayerType:
PV_PLAYER--------------------(已经不使用，原本为创建OpenCore中的PVPlayer) SONIVOX_PLAYER----------- MidiFile()(MIDI 格式) STAGEFRIGHT_PLAYER----- StagefrightPlayer
NU_PLAYER---------------------NuPlayer(流媒体播放器)
TEST_PLAYER------------------- TestPlayerStub (only for ‘test’ and ‘eng’build) //以下为与openMax插件的初始化连接。
AwesomePlayer:mClient.connect()-> OMXClient::connect->
MediaPlayerService::getOMX()->
OMXMaster::OMXMaster: addVendorPlugin ()-> addPlugin((*createOMXPlugin ())-> *createOMXPlugin (){ new TIOMXPlugin; }
2.解析mUri指定的内容，根据header来确定对应的Extractor
AwesomePlayer:: prepare()? AwesomePlayer:: prepareAsync_l()->
在该函数中启动mQueue,作为EventHandler(stagefright使用event来进行驱动) AwesomePlayer::finishSetDataSource_l()->
MediaExtractor::create(datasource)->
3.使用extractor对文件做A/V分离(mVideoTrack/mAudioTrack)
AwesomePlayer::setDataSource_l(extractor)-> AwesomePlayer::setVideoSource()-> AwesomePlayer::setAudioSource()->
mVideoTrack=source
mAudioTrack=source
4根据mVideoTrace中编码类型来选择video_decoder(mVideoSource)
AwesomePlayer::initVideoDecoder()-> mVideoSource->start();(初始化解码器) OMXCodec::Create()->
根据编码类型去匹配codecs,将softwareCodec优先放在matchCodecs前面，优先匹配，即优先建立softWareCodec
err = codec->configureCodec(meta, flags)-> return codec.
5.根据Codec类型选择Renderer
AwesomePlayer：:start-> postVideoEvent_l();
AwesomePlayer::onVideoEvent()->
mVideoSource->read()(&mVideoBuffer, &options)-> AwesomePlayer::initRenderer_l()-> 判断Codec类型， HardWare Codec：
mVideoRenderer =new AwesomeNativeWindowRenderer(mSurface, rotationDegrees); AwesomeNativeWindowRenderer::render()(hook Called by EGL)-> HardWare Codec不需要进行ColorConvert操作，直接push到NativeWindow SoftWare Codec：
mVideoRenderer = new AwesomeLocalRenderer(mSurface, meta)-> mVideoRenderer = new SoftwareRenderer()-> SoftwareRenderer::render()-> AwesomePlayer::onVideoEvent()-> [Check Timestamp]
mVideoRenderer->render(mVideoBuffer);
6.Audio和Video同步
Stagefright中Audio由CallBack驱动数据流，Video则在OnVideoEvent中获取Audio的timeStamp，进行同步。 Audio::fillBuffer()->
mPositionTimeMediaUs为资料中的timestamp, mPositionTimeRealUs为播放资料的实际时间。 AwesomePlayer::onVideoEvent()->
mTimeSourceDeltaUs = realTimeUs- mediaTimeUs
Audio Decode
1创建playerengine
// 设置数据源，以及 audio sink
MediaPlayer::SetDataSource(PATH_TO_FILE)-> MediaPlayerService::create->
MediaPlayerService::Client::setDataSource-> MediaPlayerService:: Client:: GetPlayerType-> MediaPlayerService:: Client::CreatePlayer-> StagefrightPlayer:: setAudioSink-> StagefrightPlayer:: setDataSource->
Create MediaPlayerImpl（AwesomePlayer）-> MediaPlayerImpl:: MediaPlayerImpl PlayerType:
PV_PLAYER--------------------(已经不使用，原本为创建OpenCore中的PVPlayer) SONIVOX_PLAYER----------- MidiFile()(MIDI 格式) STAGEFRIGHT_PLAYER----- StagefrightPlayer
NU_PLAYER---------------------NuPlayer(流媒体播放器)
TEST_PLAYER------------------- TestPlayerStub (only for ‘test’ and ‘eng’build) //以下为与openMax插件的初始化连接。
AwesomePlayer:mClient.connect()-> OMXClient::connect->
MediaPlayerService::getOMX()->
OMXMaster::OMXMaster: addVendorPlugin ()-> addPlugin((*createOMXPlugin ())-> *createOMXPlugin (){ new TIOMXPlugin; }
2.解析mUri指定的内容，根据header来确定对应的Extractor
AwesomePlayer:: prepare()? AwesomePlayer:: prepareAsync_l()->
在该函数中启动mQueue,作为EventHandler(stagefright使用event来进行驱动) AwesomePlayer::finishSetDataSource_l()->
MediaExtractor::create(datasource)->
3.使用extractor对文件做A/V分离(mVideoTrack/mAudioTrack)
AwesomePlayer::setDataSource_l(extractor)-> AwesomePlayer::setVideoSource()-> AwesomePlayer::setAudioSource()->
mVideoTrack=source mAudioTrack=source
4根据mAudioTrace中编码类型来选择audio_decoder(mAudioSource)
AwesomePlayer::initAudioDecoder()-> mAudioSource->start();(初始化解码器) OMXCodec::Create()->
根据编码类型去匹配codecs,将softwareCodec优先放在matchCodecs前面，优先匹配，即优先建立softWareCodec
err = codec->configureCodec(meta, flags)-> return codec.
5.创建AudioPlayer,解码并开启Audio output播放audio数据
AwesomePlayer::play_l->
mAudioPlayer = new AudioPlayer(mAudioSink, this); mAudioPlayer->setSource(mAudioSource); mAudioPlayer->start
mSource->read(&mFirstBuffer);(在audioplayer启动过程中，会先读取第一段需解码后的资料。)
mAudioSink->open(..., &AudioPlayer::AudioSinkCallback, ...); AudioSinkCallback{
me->fillBuffer(buffer, size) }
开启audio output，同时AudioPlayer将callback函数设给它，之后每次callback函数被调用，AudioPlayer便会去读取Audio decoder解码后的资料。)