视频无法使用mediaplayer和surfaceview播放

Question

public  class PlayVideoActivity extends Activity implements SurfaceHolder.Callback {
SurfaceView surfaceView;
SurfaceHolder surfaceHolder;
MediaPlayer mediaPlayer;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_play_video);
        Intent intent=getIntent();
        int no=intent.getIntExtra("index",0);
        Toast.makeText(getBaseContext(),"Hello",Toast.LENGTH_SHORT).show();
        getWindow().setFormat(PixelFormat.UNKNOWN);
        surfaceView = (SurfaceView) findViewById(R.id.surfaceView1);
        surfaceHolder = surfaceView.getHolder();
        surfaceHolder.addCallback(this);
        surfaceHolder.setFixedSize(176, 144);
        surfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
        mediaPlayer = new MediaPlayer();
        mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
        mediaPlayer.setDisplay(surfaceHolder);

        try {
            mediaPlayer.setDataSource(MainActivity.musicPath[no]);
        } catch (IllegalArgumentException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (SecurityException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IllegalStateException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        try {
            mediaPlayer.prepare();
        } catch (IllegalStateException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        mediaPlayer.start();
    }

我正在尝试使用媒体播放器和表面视图播放视频，但它没有播放，我在这里编写代码。请告诉我代码中的问题是什么？提前致谢 .................................................. .................................................. .................................................. .................................