Android中的“ Surface”类到底是什么？

Question

I have been trying for a long time to render a video on a "Surface" class using MediaPlayer class. It was playing audio, but not the video. Everywhere I search, people talk about SurfaceView and SurfaceHolder but I have only a Surface object. How to crack this blocker?

This is how I tried,

public class SampleVideoPlayer{

private Uri mUrl;
private Surface mSurface;
private MediaPlayer mMediaPlayer;
private Context mContext;

public SampleVideoPlayer(Context context, String url, Surface surface){
    mUrl = Uri.parse(url);
    mSurface = surface;
    mMediaPlayer = new MediaPlayer();
    mContext = context;
}

public void playVideo() throws IOException {
        mMediaPlayer.setDataSource(mContext, mUrl);
        mMediaPlayer.setSurface(mSurface);
        mMediaPlayer.setOnPreparedListener(new MediaPlayer.OnPreparedListener(){
            @Override
            public void onPrepared(MediaPlayer mediaPlayer) {
                mediaPlayer.start();
            }
        });
        mMediaPlayer.prepareAsync();
}

}

Adding the Session Object I am passing,

public class MyTvSession extends TvInputService.Session implements Handler.Callback {

Context mContext;
String vidUrl;
Surface mSurface;
SampleVideoPlayer player = null;
SampleMediaPlayer mediaPlayer;

public MyTvSession(Context context){
    super(context);
    ChannelXmlReader reader = new ChannelXmlReader(context);
    ArrayList<Channel> channels = reader.ReadXml();
    mContext = context;
    vidUrl = channels.get(0).url;
}
@Override
public boolean handleMessage(Message message) {
    Log.d("HANDLE MESSAGE", message.toString());
    return true;
}

@Override
public void onRelease() {

}

@Override
public boolean onSetSurface(Surface surface) {
    if(surface != null)
        Log.d("NOT NULL from SESSION", "NOTNULL");
    mSurface = surface;
    return true;
}

@Override
public void onSurfaceChanged(int format, int width, int height) {
    super.onSurfaceChanged(format, width, height);
    if(mediaPlayer != null)
        mediaPlayer.mMediaPlayer.setSurface(mSurface);

    Log.d("ONSURFACECHANGED", "Event");
}



@Override
public void onSetStreamVolume(float v) {

}

@Override
public boolean onTune(Uri uri) {
    Log.d("TUNING CHANNEL", uri.toString());
    try {
        mediaPlayer = new SampleMediaPlayer(mContext, vidUrl, mSurface);
        mediaPlayer.playVideo();
    }catch(Exception e){
        Log.d("MPEXCEPTION", Log.getStackTraceString(e));
    }
    return true;
}

@Override
public void onSetCaptionEnabled(boolean b) {

}

}

Answer 1

The Surface class is a thin wrapper around a buffer list shared with the backing surfaceflinger process, which is responsible for rendering to the display.

You can get one of these using the SurfaceView and its SurfaceHolder , which are tied to the lifecycle of the view. So be sure to get it after being called back when the surface has been created.

Alternatively, you can use a SurfaceTexture which is created using your own custom OpenGL context. With this approach you can render using your own OpenGL code or even pass it off to the media engine for rendering. You can also get a SurfaceTexture tied to the view subsystem by using TextureView (but like SurfaceView you'll need to use it at the appropriate time in its lifecycle.)

Answer 2

I have exactly the same problem. But it only happens on Philips TV. The same code runs fine on every other Android TV devices. The surface I get in onSetSurface is valid, sound is playing, but picture is black. When I close the app, the video is visible for a second. It seems to be in the background.