BiliBili-IJKPlayer播放器源码分析（一）

r囧r小猫 2022-03-15 19:57 917阅读 0赞

IJKPlayer是一款基于ffmpeg/ffplay的开源播放器，可支持rtmp/rtsp/hls等多种媒体协议，支持Android/IOS等移动平台。项目地址：https://github.com/Bilibili/ijkplayer，项目地址有可供参考的编译方式。  
“Android/iOS video player based on FFmpeg n3.1, with MediaCodec, VideoToolbox support.”  
IJKPlayer（Android）主要由Java层和JNI层组成，Java层主要负责业务控制，JNI部分主要功能是完成音视频的播放。JNI层向Java层提供接口调用，形成事件任务，同时以回调的形式向Java层推送事件完成的状态通知。  
Java层主要包括ijkplayer-exo和ijkplayer-java两个类库，分别代表两个不同的播放器。jikplayer-java里面有IMediaPlayer接口和AbstractMediaPlayer抽象类。所以ijkplayer-exo依赖于ijkplayer-java。  
ijkplayer-java的底层JNI基于ffplay。在ffplay里面，通过事件循环来实现流程的控制，ijkplayer-java不同于ffplay的事件循环，采用的是消息队列，但在本质上是一样的。  
调用流程图：

JNI提供接口形式：  
static JNINativeMethod g\_methods\[\] = \{  
    \{  
        "\_setDataSource",  
        "(Ljava/lang/String;\[Ljava/lang/String;\[Ljava/lang/String;)V",  
        (void \*) IjkMediaPlayer\_setDataSourceAndHeaders  
    \},  
    \{ "\_setDataSourceFd",       "(I)V",     (void \*) IjkMediaPlayer\_setDataSourceFd \},  
    \{ "\_setDataSource",         "(Ltv/danmaku/ijk/media/player/misc/IMediaDataSource;)V", (void \*)IjkMediaPlayer\_setDataSourceCallback \},  
   
    \{ "\_setVideoSurface",       "(Landroid/view/Surface;)V", (void \*) IjkMediaPlayer\_setVideoSurface \},  
    \{ "\_prepareAsync",          "()V",      (void \*) IjkMediaPlayer\_prepareAsync \},  
    \{ "\_start",                 "()V",      (void \*) IjkMediaPlayer\_start \},  
    \{ "\_stop",                  "()V",      (void \*) IjkMediaPlayer\_stop \},  
    \{ "seekTo",                 "(J)V",     (void \*) IjkMediaPlayer\_seekTo \},  
    \{ "\_pause",                 "()V",      (void \*) IjkMediaPlayer\_pause \},  
    \{ "isPlaying",              "()Z",      (void \*) IjkMediaPlayer\_isPlaying \},  
    \{ "getCurrentPosition",     "()J",      (void \*) IjkMediaPlayer\_getCurrentPosition \},  
    \{ "getDuration",            "()J",      (void \*) IjkMediaPlayer\_getDuration \},  
    \{ "\_release",               "()V",      (void \*) IjkMediaPlayer\_release \},  
    \{ "\_reset",                 "()V",      (void \*) IjkMediaPlayer\_reset \},  
    \{ "setVolume",              "(FF)V",    (void \*) IjkMediaPlayer\_setVolume \},  
    \{ "getAudioSessionId",      "()I",      (void \*) IjkMediaPlayer\_getAudioSessionId \},  
    \{ "native\_init",            "()V",      (void \*) IjkMediaPlayer\_native\_init \},  
    \{ "native\_setup",           "(Ljava/lang/Object;)V", (void \*) IjkMediaPlayer\_native\_setup \},  
    \{ "native\_finalize",        "()V",      (void \*) IjkMediaPlayer\_native\_finalize \},  
   
    \{ "\_setOption",             "(ILjava/lang/String;Ljava/lang/String;)V", (void \*) IjkMediaPlayer\_setOption \},  
    \{ "\_setOption",             "(ILjava/lang/String;J)V",                  (void \*) IjkMediaPlayer\_setOptionLong \},  
   
    \{ "\_getColorFormatName",    "(I)Ljava/lang/String;",    (void \*) IjkMediaPlayer\_getColorFormatName \},  
    \{ "\_getVideoCodecInfo",     "()Ljava/lang/String;",     (void \*) IjkMediaPlayer\_getVideoCodecInfo \},  
    \{ "\_getAudioCodecInfo",     "()Ljava/lang/String;",     (void \*) IjkMediaPlayer\_getAudioCodecInfo \},  
    \{ "\_getMediaMeta",          "()Landroid/os/Bundle;",    (void \*) IjkMediaPlayer\_getMediaMeta \},  
    \{ "\_setLoopCount",          "(I)V",                     (void \*) IjkMediaPlayer\_setLoopCount \},  
    \{ "\_getLoopCount",          "()I",                      (void \*) IjkMediaPlayer\_getLoopCount \},  
    \{ "\_getPropertyFloat",      "(IF)F",                    (void \*) ijkMediaPlayer\_getPropertyFloat \},  
    \{ "\_setPropertyFloat",      "(IF)V",                    (void \*) ijkMediaPlayer\_setPropertyFloat \},  
    \{ "\_getPropertyLong",       "(IJ)J",                    (void \*) ijkMediaPlayer\_getPropertyLong \},  
    \{ "\_setPropertyLong",       "(IJ)V",                    (void \*) ijkMediaPlayer\_setPropertyLong \},  
    \{ "\_setStreamSelected",     "(IZ)V",                    (void \*) ijkMediaPlayer\_setStreamSelected \},  
   
    \{ "native\_profileBegin",    "(Ljava/lang/String;)V",    (void \*) IjkMediaPlayer\_native\_profileBegin \},  
    \{ "native\_profileEnd",      "()V",                      (void \*) IjkMediaPlayer\_native\_profileEnd \},  
   
    \{ "native\_setLogLevel",     "(I)V",                     (void \*) IjkMediaPlayer\_native\_setLogLevel \},  
\};  
   
JNIEXPORT jint JNI\_OnLoad(JavaVM \*vm, void \*reserved)  
\{  
    JNIEnv\* env = NULL;  
   
    g\_jvm = vm;  
    if ((\*vm)->GetEnv(vm, (void\*\*) &env, JNI\_VERSION\_1\_4) != JNI\_OK) \{  
        return -1;  
    \}  
    assert(env != NULL);  
   
    pthread\_mutex\_init(&g\_clazz.mutex, NULL );  
   
    // FindClass returns LocalReference  
    IJK\_FIND\_JAVA\_CLASS(env, g\_clazz.clazz, JNI\_CLASS\_IJKPLAYER);  
    (\*env)->RegisterNatives(env, g\_clazz.clazz, g\_methods, NELEM(g\_methods) );  
   
    ijkmp\_global\_init();  
    ijkmp\_global\_set\_inject\_callback(inject\_callback);  
   
    FFmpegApi\_global\_init(env);  
   
    return JNI\_VERSION\_1\_4;  
\}