MediaPlayer是Android最基礎(chǔ)的播放器姨蝴，一般播放本地文件就會使用MediaPlayer打颤；
關(guān)于MediaPlayer的基礎(chǔ)用法的相關(guān)文章到處都是，本文就不在詳細(xì)解說了枉层；
Mediaplayer的使用贰拿，主要是記住他的狀態(tài)機(jī)

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下面來一起看一下他的內(nèi)部實(shí)現(xiàn)

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參考文檔:
MediaPlayer框架概述
上面這個(gè)網(wǎng)站講的還是比較清楚的
1.java framwork層的MediaPlayer.java通過JNI調(diào)用android_media_mediaplayer.cpp的方法规哪，在native framwork層映射了一個(gè)MediaPlayer.cpp,
2.MediaPlayer.cpp 和MediaPlayerService之間一對aidl
3.MediaPlayerService內(nèi)部實(shí)現(xiàn)會交給NuPlayer
4.NuPlayer才是實(shí)際去進(jìn)行視頻播放的播放器求豫，NuPlayer會把視頻資源分解成AudioTrack和VideoTrack
5.VideoTrack交給SurfaceFlinger去處理
6.AudioTrack交給AudioFlinger去處理；
7.最終形成視頻播放；
關(guān)鍵類都在這個(gè)下面

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NuPlayer源碼解析:
參考文檔：
NuPlayer源碼分析（一）
NuPlayer源碼分析（二）

status_t NuPlayer::GenericSource::initFromDataSource() {
    ...
    /* 創(chuàng)建數(shù)據(jù)提取器 */
    extractor = MediaExtractor::Create(mDataSource,
            mSniffedMIME.empty() ? NULL: mSniffedMIME.c_str());
    ...
    /* 分離音視頻track */
    for (size_t i = 0; i < numtracks; ++i) {
        sp<MediaSource> track = extractor->getTrack(i);
        if (track == NULL) {
            continue;
        }

        sp<MetaData> meta = extractor->getTrackMetaData(i);

        const char *mime;
        CHECK(meta->findCString(kKeyMIMEType, &mime));

        // Do the string compare immediately with "mime",
        // we can't assume "mime" would stay valid after another
        // extractor operation, some extractors might modify meta
        // during getTrack() and make it invalid.
        if (!strncasecmp(mime, "audio/", 6)) {
            if (mAudioTrack.mSource == NULL) {
                mAudioTrack.mIndex = i;
                mAudioTrack.mSource = track;
                mAudioTrack.mPackets =
                    new AnotherPacketSource(mAudioTrack.mSource->getFormat());

                if (!strcasecmp(mime, MEDIA_MIMETYPE_AUDIO_VORBIS)) {
                    mAudioIsVorbis = true;
                } else {
                    mAudioIsVorbis = false;
                }
            }
        } else if (!strncasecmp(mime, "video/", 6)) {
            if (mVideoTrack.mSource == NULL) {
                mVideoTrack.mIndex = i;
                mVideoTrack.mSource = track;
                mVideoTrack.mPackets =
                    new AnotherPacketSource(mVideoTrack.mSource->getFormat());

                // check if the source requires secure buffers
                int32_t secure;
                if (meta->findInt32(kKeyRequiresSecureBuffers, &secure)
                        && secure) {
                    mIsSecure = true;
                    if (mUIDValid) {
                        extractor->setUID(mUID);
                    }
                }
            }
        }
        ...
    }
}