Question

目前，我有一个工作原型应用程序，可将一部手机的相机输出流式传输到另一部手机的屏幕。

然而，流与实际视频之间的延迟范围从1秒到最多5秒。对于我的特定用例，我需要延迟不到1秒。

我发现比特率/分辨率不会影响延迟。

我正在使用libstreaming library通过wifi-direct传输h264视频。

它似乎只支持h263或h264的编码......我发现h263不能像h264那样一致。

以下是捕获视频和流到RTSP服务器的代码：

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_server);
    setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
    getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);

    mSurfaceView = (SurfaceView) findViewById(R.id.surface);

    // Sets the port of the RTSP server to 8988
    Editor editor = PreferenceManager.getDefaultSharedPreferences(
            getApplicationContext()).edit();
    editor.putString(RtspServer.KEY_PORT, String.valueOf(8988));
    editor.commit();

    // Get bitrate
    int bitrate = Integer.valueOf(getIntent().getStringExtra(BITRATE));
    if (bitrate < 100000)
        bitrate = 100000;

    // Get resolution
    String resolution = getIntent().getStringExtra(RESOLUTION);
    int resX = 176;
    int resY = 144;
    if (resolution.equals("352x288")) {
        resX = 352;
        resY = 288;
    } else if (resolution.equals("528x432")) {
        resX = 528;
        resY = 432;
    } else if (resolution.equals("704x576")) {
        resX = 704;
        resY = 576;
    } else {
        resX = 176;
        resY = 144;
    }

    Toast.makeText(this, "Resolution: " + resX + "x" + resY + ", Bitrate: "
            + bitrate, Toast.LENGTH_LONG).show();

    // Configures the SessionBuilder
    SessionBuilder.getInstance().setSurfaceView(mSurfaceView)
            .setPreviewOrientation(0).setContext(this)
            .setVideoQuality(new VideoQuality(resX, resY, 20, bitrate))
            .setAudioEncoder(SessionBuilder.AUDIO_NONE)
            .setVideoEncoder(SessionBuilder.VIDEO_H264);
    // Starts the RTSP server
    getApplicationContext().startService(
            new Intent(getApplicationContext(), RtspServer.class));
}

这是观看流媒体视频的代码：

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_client);

    mVideoIP = getIntent().getStringExtra(SERVER_IP);

    mSurfaceView = (SurfaceView) findViewById(R.id.surface_view);
    mSurfaceHolder = mSurfaceView.getHolder();
    mSurfaceHolder.addCallback(this);


    if (savedInstanceState == null) {

    }
}
...
    @Override
public void surfaceCreated(SurfaceHolder holder) {
    try {
        mMediaPlayer = new MediaPlayer();
        mMediaPlayer.setDisplay(mSurfaceHolder);
        mMediaPlayer.setDataSource("rtsp://" + mVideoIP
                + ":8988");
        mMediaPlayer.prepare();
        mMediaPlayer.setOnPreparedListener(this);
        mMediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
        mMediaPlayer.setScreenOnWhilePlaying(true);
    } catch (IllegalArgumentException e) {
        e.printStackTrace();
    } catch (SecurityException e) {
        e.printStackTrace();
    } catch (IllegalStateException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

减少wifi直接视频流应用中的延迟

0 个答案: