Android MediaCodec trace
来自个人维基
2020年6月13日 (六) 19:57free6d1823(讨论 | 贡献)的版本
- MediaPlayer calling flow
MediaPlayer mp = new MediaPlayer(); 1. mp.setDataSource(filePath); 2. mp.setDisplay(MediaFrameworkTest.mSurfaceView.getHolder()); 3. mp.prepare(); //获取和解码媒体数据 4. mp.start(); 5. FillBuffer 6. EmptyBuffer
1. setDataSource(filePath)
<MediaPlayerBase> mPlayer = Create form (playerType of source); // => new NuPlayerDriver(pid) { mLooper->setName("NuPlayerDriver Looper")->start(PRIORITY_AUDIO); mPlayer = new NuPlayer(pid); } //绑定Extractor、omx、codec2服务的death监听, //mPlayer->setDataSource(dataSource)
2. MediaPlayer.java: setDisplay(SurfaceHolder sh) or setSurface(Surface surface)
=> native void _setVideoSurface(Surface surface); => => /frameworks/base/media/jni/android_media_MediaPlayer.cpp: android_media_MediaPlayer_setVideoSurface(JNIEnv *env, jobject thiz, jobject jsurface) => setVideoSurface(JNIEnv *env, jobject thiz, jobject jsurface, jboolean mediaPlayerMustBeAlive) { sp<IGraphicBufferProducer> new_st = surface->getIGraphicBufferProducer(); MediaPlyer getMediaPlayer()->setVideoSurfaceTexture(new_st); } => libmediaplayerservice/MediaPlayerService.cpp: MediaPlayerService::Client::setVideoSurfaceTexture(<IGraphicBufferProducer>& bufferProducer) { sp<ANativeWindow> anw; anw = new Surface(bufferProducer, true /* controlledByApp */); nativeWindowConnect(anw.get(), "setVideoSurfaceTexture"); getPlayer()->setVideoSurfaceTexture(bufferProducer); mConnectedWindow = anw; //decoder mConnectedWindowBinder = binder(IInterface::asBinder(bufferProducer)); } => libmediaplayerservice/nuplayer/NuPlayerDriver.cpp: NuPlayerDriver::setVideoSurfaceTexture(&bufferProducer) { }
3. prepare
NuPlayer::GenericSource::onPrepareAsync(){ dataSource = DataSourceFactory::CreateFromURI(uri) or new FileSource(mFd, mOffset, mLength); <IMediaExtractor> ex = mediaExService->makeExtractor() => MediaExtractorFactory::CreateFromService(localSource, mime); => creator = sniff(source, &confidence, &meta, &freeMeta, plugin, &creatorVersion);==> find best creator from ExtractorPlugin gPlugins list.
4. start
void NuPlayer::start()==> (new AMessage(kWhatStart, this))->post(); NuPlayer::onMessageReceived(const sp<AMessage> &msg) { case kWhatStart: onStart();} => NuPlayer::onStart(int64_t startPositionUs, MediaPlayerSeekMode mode) => mSource->start(); hasVideo = (mSource->getFormat(false /* audio */) != NULL); mRenderer = new Renderer(mAudioSink, mMediaClock, notify, flags); mRendererLooper = new ALooper; mRendererLooper->start(false, false, ANDROID_PRIORITY_AUDIO); mRenderer->setPlaybackSettings(mPlaybackSettings); mRendererLooper->registerHandler(mRenderer); mRenderer->setVideoFrameRate(rate); postScanSources()=> (new AMessage(kWhatScanSources, this))->post(); => NuPlayer::onMessageReceived( kWhatScanSources) { instantiateDecoder(false, &mVideoDecoder) { notify = new AMessage(kWhatVideoNotify, this); *decoder = new Decoder(notify, mSource, mPID, mUID, mRenderer, mSurface, mCCDecoder); format->setInt32("auto-frc", 1);// enable FRC if high-quality AV sync is requested (*decoder)->init(); (*decoder)->configure(format); //buffer <ABuffer> inputBufs = (*decoder)->getInputBuffers(); for each buffer in inputBufs[i], mbuf = new MediaBuffer(buffer->data(), buffer->size()); mediaBufs.push(mbuf); mSource->setBuffers(audio, mediaBufs); } } NuPlayer::Decoder::onConfigure(const sp<AMessage> &format) { mComponentName = format->findString("mime")="audio/ video/xxx"+"decoder"; mCodec = MediaCodec::CreateByType(mCodecLooper, mime, false /* encoder */, NULL /* err */, mPid); // disconnect from surface as MediaCodec will reconnect mCodec->configure(format, mSurface, NULL /* crypto */, 0 /* flags */); rememberCodecSpecificData(format); mCodec->getOutputFormat(&mOutputFormat); mCodec->getInputFormat(&mInputFormat)); //find width and height from mOutputFormat() mCodec->setCallback(reply); mCodec->start(); releaseAndResetMediaBuffers(); } mCodec->initiateAllocateComponent(format);=> msg->setWhat(kWhatAllocateComponent);=> msg->setWhat(kWhatAllocateComponent); ACodec::UninitializedState::onAllocateComponent(msg) { OMXClient client; client.connect(); <IOMX> omx = client.interface(); OMXCodec::findMatchingCodecs(mime, encoder, &matchingCodecs); omx->allocateNode(componentName.c_str(), observer, &node); mCodec->mNotify->("CodecBase::kWhatComponentAllocated") }
MediaCodec::onInputBufferAvailable() NuPlayer::Decoder::handleAnInputBuffer(…) NuPlayer::Decoder::onInputBufferFetched(…) OMX::emptyBuffer(…), //decode SoftOMXComponent::notifyEmptyBufferDone(…) OMX::OnEmptyBufferDone(…) ACodec::BaseState::onOMXEmptyBufferDone(…)
6. Decoder output
ref:https://blog.csdn.net/yanbixing123/article/details/88937106?utm_medium=distribute.pc_relevant.none-task-blog-BlogCommendFromMachineLearnPai2-1.nonecase&depth_1-utm_source=distribute.pc_relevant.none-task-blog-BlogCommendFromMachineLearnPai2-1.nonecase
ref: https://blog.csdn.net/yanbixing123/article/details/88925903#comments
ACodec::ExecutingState::submitOutputBuffers() ACodec::BaseState::postFillThisBuffer(…) OMX:: fillBuffer (…) SimpleSoftOMXComponent::fillThisBuffer(…) //write decoded output SoftOMXComponent::notifyFillBufferDone(…) OMX:: OnFillBufferDone (…) ACodec::BaseState:: onOMXFillBufferDone (…); NuPlayer::Decoder::handleAnOutputBuffer(…)