ACodec从UninitializedState状态到LoadedState状态分析-白红宇

ACodec从UninitializedState状态到LoadedState状态分析

阅读量：380 次

发布时间：2019-03-05

本文共 2603 字，大约阅读时间需要 8 分钟。

MediaCodec native???????create?config

MediaCodec??Android??????????native??????create?config?????????????????????????????????

????

?????mediacodec?create?config????native??????????????????????

??create?native?????

?mediacodec?????????????ACodec???ACodec???????????????????UninitializedState???????????

MediaCodec.cppstatus_t MediaCodec::init(const AString &name, bool nameIsType, bool encoder) {    // 1. ???ACodec    mCodec = new ACodec;        // 2. ?MediaCodec??????ALooper???ACodec??????    if (needDedicatedLooper) {        if (mCodecLooper == NULL) {            mCodecLooper = new ALooper;            mCodecLooper->setName("CodecLooper");            mCodecLooper->start(false, false, ANDROID_PRIORITY_AUDIO);        }        mCodecLooper->registerHandler(mCodec);    } else {        // 3. ?ACodec???MediaCodec???ALooper?        mLooper->registerHandler(mCodec);    }        // 4. ?MediaCodec???jni????ALooper?    mLooper->registerHandler(this);    mCodec->setNotificationMessage(new AMessage(kWhatCodecNotify, id()));        // 5. ????kWhatInit??    sp
   
            msg = new AMessage(kWhatInit, id());        msg->setString("name", name);        msg->setInt32("nameIsType", nameIsType);        if (nameIsType) {            msg->setInt32("encoder", encoder);        }    sp
    
         response;    return PostAndAwaitResponse(msg, &response);}

?????

?????init?????????ACodec???ACodec??????????????AHierarchicalStateMachine????

??????kWhatInit??????onMessageReceived?????

?onMessageReceived??????????kWhatInit??????????UNINITIALIZED????????mReplyID??????INITIALIZING????ACodec?initiateAllocateComponent???

ACodec?????

ACodec?????AHierarchicalStateMachine????????UninitializedState?????changeState???????UninitializedState???kWhatAllocateComponent??????onAllocateComponent???