Android: Mediaplayer: How to use SurfaceView or me

问题:

I am playing local video file using MediaPlayer and SurfaceView. SurfaceView is the only control in activity, while my video files are QVGA or other. Problem is that video is getting stretched, How can i play video in its original size e.g. qvga with remaining area black.

From iteration,

When i am forcefully sets layout_height/width of Surfaceview in XML, video displayed fine. surface_holder.setFixedSize(w,h) has no effect, neither mp.setdisplay().

Please guide in this.

UPDATE

XML flie

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android" 
            android:id="@+id/home_container"  
            android:layout_width="fill_parent" 
            android:layout_height="fill_parent">

<SurfaceView 
        android:id="@+id/surface" 
        android:layout_width="fill_parent" 
        android:layout_height="wrap_content" 
        android:paddingTop="10dip" />
</framelayout>

MediaPlayer usage is as per following link

http://davanum.wordpress.com/2007/12/29/android-videomusic-player-sample-from-local-disk-as-well-as-remote-urls/

Thanks in advance.

回答1:

On your SurfaceView in XML are you using wrap_content ? This should fix your problem if not. You may need to paste a little more code for further investigation if that doesn't fix your problem.

Change your surface view width to wrap_content as well.

回答2:

Setting your SurfaceView layout to wrap_content will not size a video to play at the proper aspect ratio.

• A SurfaceView is an optimized drawing surface
• A video is drawn to a SurfaceView, not contained within it

wrap_content is synonymous with fill_parent for a SurfaceView.

What you want to do is get the dimensions of your video from the MediaPlayer object. You can then set the aspect ratio of the SurfaceView to match the video.

Some Basic initialization

public class YourMovieActivity extends Activity implements SurfaceHolder.Callback {
    private MediaPlayer mp = null;
    //...

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        mp = new MediaPlayer();
        mSurfaceView = (SurfaceView) findViewById(R.id.surface);
        //...
    }
}

Then the good stuff. I have omitted error checking here to reduce code, MediaPlayer calls should be wrapped in a try{}.

@Override
public void surfaceCreated(SurfaceHolder holder) {

    mp.setDataSource("/sdcard/someVideo.mp4");
    mp.prepare();

    //Get the dimensions of the video
    int videoWidth = mp.getVideoWidth();
    int videoHeight = mp.getVideoHeight();

    //Get the width of the screen
    int screenWidth = getWindowManager().getDefaultDisplay().getWidth();

    //Get the SurfaceView layout parameters
    android.view.ViewGroup.LayoutParams lp = mSurfaceView.getLayoutParams();

    //Set the width of the SurfaceView to the width of the screen
    lp.width = screenWidth;

    //Set the height of the SurfaceView to match the aspect ratio of the video 
    //be sure to cast these as floats otherwise the calculation will likely be 0
    lp.height = (int) (((float)videoHeight / (float)videoWidth) * (float)screenWidth);

    //Commit the layout parameters
    mSurfaceView.setLayoutParams(lp);        

    //Start video
    mp.start();
}

Note that this code makes some assumptions about the dimensions of your video. As-is, it maximizes the width and assumes that the height is not greater than the height of the screen.

You may want to fit height instead of width, also you could check the dimension calculation and ensure that it is not greater than the screen or screen - other_layout_elements.

回答3:

here is the code I currently use in a project:

private MediaPlayer mMediaPlayer;
private SurfaceView mSurfaceView;
private SurfaceHolder holder;
private int mPos = 0;

...

int width = mSurfaceView.getWidth();
int height = mSurfaceView.getHeight();
float boxWidth = width;
float boxHeight = height;

float videoWidth = mMediaPlayer.getVideoWidth();
float videoHeight = mMediaPlayer.getVideoHeight();

Log.i(TAG, String.format("startVideoPlayback @ %d - video %dx%d - box %dx%d", mPos, (int) videoWidth, (int) videoHeight, width, height));

float wr = boxWidth / videoWidth;
float hr = boxHeight / videoHeight;
float ar = videoWidth / videoHeight;

if (wr > hr)
    width = (int) (boxHeight * ar);
else
    height = (int) (boxWidth / ar);

Log.i(TAG, String.format("Scaled to %dx%d", width, height));

holder.setFixedSize(width, height);
mMediaPlayer.seekTo(mPos);
mMediaPlayer.start();

the layout I'm using (you can just ignore the progress bar)

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:gravity="center"
    android:orientation="vertical" >

<ProgressBar
    android:id="@+id/progressBar1"
    style="?android:attr/progressBarStyleHorizontal"
    android:layout_width="match_parent"
    android:layout_height="wrap_content" />

<SurfaceView
    android:id="@+id/surface"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="center" >
</SurfaceView>