最近在做音视频相关的内容，这就无法避开视屏采集和播放的问题了，然后播放器使用的是 ijkplayer，这个东西使用 url 播放倒是没啥问题，只是我们的方案是接收 flv 的视频流进行播放，这需要借助 IAndroidIO 这个接口，也可以用于播放本地文件。

实现 IAndroidIO 接口

播放类的实现

class ReadByteIO private constructor(): IAndroidIO {

    companion object {
        private var instance: ReadByteIO? = null
        var URL_SUFFIX = "recv_data_online"

        @Synchronized
        fun getInstance(): ReadByteIO { // 单例
            instance?.let {
                return it
            }
            instance = ReadByteIO()
            return instance!!
        }
    }

    private var TAG = ReadByteIO::class.java.simpleName
    private var flvData = LinkedBlockingDeque<Byte>()  // 内存队列，用于缓存获取到的流数据，要实现追帧效果，只需要根据策略丢弃本地缓存的内容即可

    private fun takeFirstWithLen(len : Int): ByteArray {  // 取 byte 数据用于界面渲染
        var byteList = ByteArray(len)
        for (i in 0 until len) {
            byteList[i] = flvData.take()
        }
        return byteList
    }

    @Synchronized
    fun addLast(bytes: ByteArray): Boolean {
        var tmpList:List<Byte> = bytes.toList()
        Log.e(TAG, "tmpList size " + tmpList.size)
        return flvData.addAll(tmpList)
    }

	// 如果是播放本地文件，可在此处打开文件流，后续读取文件流即可
    override fun open(url: String?): Int {
        if (url == URL_SUFFIX) {
            return 1 // 打开播放流成功        
            }
        return -1 // 打开播放流失败
    }

    override fun read(buffer: ByteArray?, size: Int): Int {
        var tmpBytes = takeFirstWithLen(size) // 阻塞式读取，没有数据不渲染画面
        System.arraycopy(tmpBytes, 0, buffer, 0, size)
        return size
    }

    override fun seek(offset: Long, whence: Int): Long {
        return 0
    }

    override fun close(): Int {
        return 0
    }
}

调用播放类

接下来，就看看如何调用播放实例了。注意：我们还是需要传入一个 url，只是这个 url 是我们自定义的

public class RecordVideoActivity extends AppCompatActivity implements TextureView.SurfaceTextureListener {

    private String TAG = RecordVideoActivity.class.getSimpleName();
    private IjkMediaPlayer player;
    private Surface surface;
    private TextureView playView;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_record_video);
        playView = findViewById(R.id.v_play);
        playView.setSurfaceTextureListener(this);
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        if (player != null) {
            player.stop();
        }
    }

    @Override
    public void onSurfaceTextureAvailable(SurfaceTexture surface, int width, int height) {
        if (surface != null) {
            this.surface = new Surface(surface);
            play();  // 存在 surface 实例再做播放
        }
    }
    @Override
    public void onSurfaceTextureSizeChanged(SurfaceTexture surface, int width, int height) { }
    @Override
    public boolean onSurfaceTextureDestroyed(SurfaceTexture surface) {return false; }
    @Override
    public void onSurfaceTextureUpdated(SurfaceTexture surface) { }

    private void play() {
        player = new IjkMediaPlayer();
        player.reset();
        player.setOption(IjkMediaPlayer.OPT_CATEGORY_FORMAT, "analyzemaxduration", 100);
        player.setOption(IjkMediaPlayer.OPT_CATEGORY_FORMAT, "probesize", 25 * 1024);
        player.setOption(IjkMediaPlayer.OPT_CATEGORY_PLAYER, "packet-buffering", 0);
        player.setOption(IjkMediaPlayer.OPT_CATEGORY_PLAYER, "start-on-prepared", 1);
        player.setOption(IjkMediaPlayer.OPT_CATEGORY_CODEC, "threads", 1);
        player.setOption(IjkMediaPlayer.OPT_CATEGORY_PLAYER, "sync-av-start", 0);
        player.setOption(IjkMediaPlayer.OPT_CATEGORY_PLAYER, "mediacodec",1);
        player.setOption(IjkMediaPlayer.OPT_CATEGORY_PLAYER, "mediacodec-auto-rotate", 1);
        player.setOption(IjkMediaPlayer.OPT_CATEGORY_PLAYER, "mediacodec-handle-resolution-change", 1);
        player.setOption(IjkMediaPlayer.OPT_CATEGORY_FORMAT, "protocol_whitelist", "ijkio,crypto,file,http,https,tcp,tls,udp"); // 属性设置支持，转入我们自定义的播放类

        player.setSurface(this.surface);
        player.setAndroidIOCallback(ReadByteIO.Companion.getInstance());

        Uri uri = Uri.parse("ijkio:androidio:" + ReadByteIO.Companion.getURL_SUFFIX()); // 设定我们自定义的 url
        try {
            player.setDataSource(uri.toString());
        } catch (IOException e) {
            e.printStackTrace();
        }
        player.prepareAsync();
        player.start();
    }
}