android 集成直播基础视频播放器，只有声音没有画面

public class MainActivity extends AppCompatActivity {
  
    AliVcMediaPlayer mPlayer;
    SurfaceView mSurfaceView;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
  
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mSurfaceView = findViewById(R.id.surface_view);
        mSurfaceView.getHolder().addCallback(mCallback);
        mPlayer = new AliVcMediaPlayer(this, mSurfaceView);

    }


    SurfaceHolder.Callback mCallback = new SurfaceHolder.Callback() {
  
        @Override
        public void surfaceCreated(SurfaceHolder surfaceHolder) {
  
//            mPlayer.prepareAndPlay("http://zbjs.yuge.com/zhibo/record/yixin/10062961-jvoz3f9e/2019-05-15-16-38-29_2019-05-15-16-39-50.mp4");
            mPlayer.prepareAndPlay("http://im.yuge.com/im/yx/attachment/video/ma48mnpkqdrqpq22c0med3804.mp4");
        }

        @Override
        public void surfaceChanged(SurfaceHolder surfaceHolder, int i, int i1, int i2) {
  
        }

        @Override
        public void surfaceDestroyed(SurfaceHolder surfaceHolder) {
  
        }
    };
}

public class MyApplication extends Application {
  
    @Override
    public void onCreate() {
  
        super.onCreate();
        AliVcMediaPlayer.init(this);
    }
}

android {
  
    compileSdkVersion 28
    defaultConfig {
  
        applicationId "com.zk.aliplayerdemo"
        minSdkVersion 16
        targetSdkVersion 28
        versionCode 1
        versionName "1.0"
    }
    buildTypes {
  
        release {
  
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }
    allprojects {
  
        repositories {
  
            jcenter()
            flatDir {
  
                dirs 'libs'
            }
        }
    }
}

dependencies {
  
    implementation fileTree(dir: 'libs', include: ['*.jar', '*.aar'])
    implementation 'com.android.support:appcompat-v7:28.0.0'
    implementation 'com.android.support.constraint:constraint-layout:1.1.3'

    compile 'com.aliyun.dpa:oss-android-sdk:+'
}