Fixed bugs in the media player api demo application

- release the MediaPlayer object when onPause
- use onVideoSizeChanged listener to make sure that correct video size is known before starting playback

samples/ApiDemos/src/com/example/android/apis/media/MediaPlayerDemo_Video.java

@@ -9,6 +9,8 @@ import android.media.AudioManager;
 import android.media.MediaPlayer;
 import android.media.MediaPlayer.OnBufferingUpdateListener;
 import android.media.MediaPlayer.OnCompletionListener;
+import android.media.MediaPlayer.OnPreparedListener;
+import android.media.MediaPlayer.OnVideoSizeChangedListener;
 import android.os.Bundle;
 import android.util.Log;
 import android.view.SurfaceHolder;
@@ -21,7 +23,7 @@ import android.widget.Toast;
 
 public class MediaPlayerDemo_Video extends Activity implements
         OnBufferingUpdateListener, OnCompletionListener,
-        MediaPlayer.OnPreparedListener, SurfaceHolder.Callback {
+        OnPreparedListener, OnVideoSizeChangedListener, SurfaceHolder.Callback {
 
     private static final String TAG = "MediaPlayerDemo";
     private int mVideoWidth;
@@ -37,6 +39,8 @@ public class MediaPlayerDemo_Video extends Activity implements
     private static final int RESOURCES_AUDIO = 3;
     private static final int LOCAL_VIDEO = 4;
     private static final int STREAM_VIDEO = 5;
+    private boolean mIsVideoSizeKnown = false;
+    private boolean mIsVideoReadyToBePlayed = false;
 
     /**
      * 
@@ -54,6 +58,7 @@ public class MediaPlayerDemo_Video extends Activity implements
     }
 
     private void playVideo(Integer Media) {
+        doCleanUp();
         try {
 
             switch (Media) {
@@ -109,6 +114,7 @@ public class MediaPlayerDemo_Video extends Activity implements
             mMediaPlayer.setOnBufferingUpdateListener(this);
             mMediaPlayer.setOnCompletionListener(this);
             mMediaPlayer.setOnPreparedListener(this);
+            mMediaPlayer.setOnVideoSizeChangedListener(this);
             mMediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
 
 
@@ -126,15 +132,26 @@ public class MediaPlayerDemo_Video extends Activity implements
         Log.d(TAG, "onCompletion called");
     }
 
+    public void onVideoSizeChanged(MediaPlayer mp, int width, int height) {
+        Log.v(TAG, "onVideoSizeChanged called");
+        if (width == 0 || height == 0) {
+            Log.e(TAG, "invalid video width(" + width + ") or height(" + height + ")");
+            return;
+        }
+        mIsVideoSizeKnown = true;
+        mVideoWidth = width;
+        mVideoHeight = height;
+        if (mIsVideoReadyToBePlayed && mIsVideoSizeKnown) {
+            startVideoPlayback();
+        }
+    }
+
     public void onPrepared(MediaPlayer mediaplayer) {
         Log.d(TAG, "onPrepared called");
-        mVideoWidth = mMediaPlayer.getVideoWidth();
-        mVideoHeight = mMediaPlayer.getVideoHeight();
-        if (mVideoWidth != 0 && mVideoHeight != 0) {
-            holder.setFixedSize(mVideoWidth, mVideoHeight);
-            mMediaPlayer.start();
+        mIsVideoReadyToBePlayed = true;
+        if (mIsVideoReadyToBePlayed && mIsVideoSizeKnown) {
+            startVideoPlayback();
         }
-
     }
 
     public void surfaceChanged(SurfaceHolder surfaceholder, int i, int j, int k) {
@@ -148,22 +165,43 @@ public class MediaPlayerDemo_Video extends Activity implements
 
 
     public void surfaceCreated(SurfaceHolder holder) {
-        // TODO Auto-generated method stub
         Log.d(TAG, "surfaceCreated called");
         playVideo(extras.getInt(MEDIA));
 
 
     }
 
+    @Override
+    protected void onPause() {
+        super.onPause();
+        releaseMediaPlayer();
+        doCleanUp();
+    }
+
     @Override
     protected void onDestroy() {
         super.onDestroy();
-        // TODO Auto-generated method stub
+        releaseMediaPlayer();
+        doCleanUp();
+    }
+
+    private void releaseMediaPlayer() {
         if (mMediaPlayer != null) {
             mMediaPlayer.release();
             mMediaPlayer = null;
         }
-
     }
 
+    private void doCleanUp() {
+        mVideoWidth = 0;
+        mVideoHeight = 0;
+        mIsVideoReadyToBePlayed = false;
+        mIsVideoSizeKnown = false;
+    }
+
+    private void startVideoPlayback() {
+        Log.v(TAG, "startVideoPlayback");
+        holder.setFixedSize(mVideoWidth, mVideoHeight);
+        mMediaPlayer.start();
+    }
 }