【Libgdx 原创】在 Libgdx 中播放视频实例

我现在做的一款游戏使用 Libgdx ，其中需要播放小段视频过度游戏场景，想到传统的办法是跳转 Activity ,显然这样做不是我会选择的！
我想直接在当前游戏 Activity 中插播视频。
播放视频其实只需要：MediaPlayer 和 SurfaceView 

刚开始在网上找到了一段这样的实例代码，拿来用没问题

  1: public class VideoPlayerActivity extends Activity implements
  2:         MediaPlayer.OnCompletionListener,
  3:         MediaPlayer.OnPreparedListener,
  4:         SurfaceHolder.Callback,
  5:         OnClickListener {
  6:
  7:     private SurfaceView surfaceView;
  8:     private MediaPlayer mPlayer; // MediaPlayer对象
  9:     private SurfaceHolder mSurfaceHolder; // SurfaceHolder对象
 10:
 11:     private Button mSkipVideoBtn;
 12:
 13:     @Override
 14:     protected void onCreate(Bundle savedInstanceState) {
 15:         super.onCreate(savedInstanceState);
 16:         requestWindowFeature(Window.FEATURE_NO_TITLE);
 17:         getWindow().setFlags(0x400, 0x400);
 18:
 19:         setContentView(R.layout.video_player);
 20:
 21:         surfaceView = (SurfaceView) findViewById(R.id.surfaceView);
 22:
 23:         /* 初始化mSurfaceHolder */
 24:         mSurfaceHolder = surfaceView.getHolder();
 25:         mSurfaceHolder.addCallback(this); // 设置回调接口
 26:         mSurfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS); // 设置为Buffer类型（播放视频&Camera预览）
 27:
 28:         /* 初始化MediaPlayer */
 29:         mPlayer = MediaPlayer.create(this, getIntent().getIntExtra("resId", R.raw.video2));
 30:         mPlayer.setOnPreparedListener(this);
 31:         mPlayer.setOnCompletionListener(this);
 32:
 33:         mSkipVideoBtn = (Button) findViewById(R.id.button1);
 34:         mSkipVideoBtn.setOnClickListener(this);
 35:     }
 36:
 37:     @Override
 38:     protected void onDestroy() {
 39:         mPlayer.release();
 40:         super.onDestroy();
 41:     }
 42:
 43:     @Override
 44:     public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
 45:         // TODO Auto-generated method stub
 46:
 47:         String s = "#E0D8C8";
 48:          int c = Integer.parseInt(s, 16);
 49:          surfaceView.setBackgroundColor(Color.rgb(c>>24, (c>>16)&0x0000ff00, c&0x000000ff));
 50:     }
 51:
 52:     @Override
 53:     public void surfaceCreated(SurfaceHolder holder) {
 54:         mPlayer.setDisplay(holder); // 指定SurfaceHolder
 55:         // mPlayer.prepareAsync(); // 异步准备（将回调OnPreparedListener接口）
 56:     }
 57:
 58:     @Override
 59:     public void surfaceDestroyed(SurfaceHolder holder) {
 60:         // TODO Auto-generated method stub
 61:
 62:     }
 63:
 64:     @Override
 65:     public void onPrepared(MediaPlayer player) {
 66:         /* 获得窗口宽长 */
 67:         Display display = getWindowManager().getDefaultDisplay();
 68:         int wWidth = display.getWidth();
 69:         int wHeight = display.getHeight();
 70:
 71:         /* 获得视频宽长 */
 72:         int vWidth = mPlayer.getVideoWidth();
 73:         int vHeight = mPlayer.getVideoHeight();
 74:
 75:         /* 最适屏幕 */
 76:         float wRatio = (float) vWidth / (float) wWidth; // 宽度比
 77:         float hRatio = (float) vHeight / (float) wHeight; // 高度比
 78:         float ratio = Math.max(wRatio, hRatio); // 较大的比
 79:         vWidth = (int) Math.ceil((float) vWidth / ratio); // 新视频宽度
 80:         vHeight = (int) Math.ceil((float) vHeight / ratio); // 新视频高度
 81:
 82:         // 改变SurfaceHolder大小
 83:         mSurfaceHolder.setFixedSize(vWidth, vHeight);
 84:         // 设置新布局参数（这在samsung i9088上出现stretch的错误==）
 85:         // surfaceView.setLayoutParams(new LinearLayout.LayoutParams(vWidth,
 86:         // vHeight));
 87:         // 启动播放
 88:         mPlayer.start();
 89:     }
 90:
 91:     @Override
 92:     public void onCompletion(MediaPlayer mp) {
 93:         // mSkipVideoBtn.setText("开始游戏");
 94:         // Toast.makeText(this, "播放完毕！", Toast.LENGTH_SHORT).show();
 95:         finish();
 96:     }
 97:
 98:     @Override
 99:     public void onClick(View v) {
100:         mPlayer.stop();
101:         finish();
102:     }
103: }

这里最主要的就是: MediaPlayer.setDisplay()，新建一个SurfaceView，将 SurfaceView 的 SurfaceHolder 设置给 MediaPlayer 然后设置播放视频，prepare() 、 start() 就可以正常播放视频了，不过据说只支持 .mp4 .3gp，我没亲测。

起初这段源代码给我带来帮助，在感谢原作者之余他也在代码里设下了一个陷阱，作者当时估计没测试到就是！

如果你使用这段代码，在有些手机上是可以正常播放视频的，而有些手机就是不行（你只能听见声音、看不到画面），系统没给任何提示，只有2个警告信息，如下图：

于是百度“mediaPlayer错误信息”得知 35 在 native 层是这样定义的：const PVMFStatus PVMFInfoTrackDisable = 35;

于是 Google “PVMFInfoTrackDisable ” 果然有人跟我遇到同样的问题，在 stackoverflow 论坛有一篇这样的帖子：

http://stackoverflow.com/questions/7509818/android-mediaplayer-sometimes-no-video-is-played-even-though-audio-plays

这里不得不说下，stackoverflow 论坛能够找到你遇到的各种疑难杂症，嘿嘿！

这里面说法很多，但没找到根本原因，倒是在另外一篇帖子找到了答案：

这哥们才发现了问题的根本，大概意思就是：在 surfaceCreated 没被系统调用之前，SurfaceView 的 SurfaceHolder 是无效的，而我们一般习惯在 MediaPlayer 构造完后就给他设置数据，而我在 surfaceCreated 才调用了 mPlayer.setDisplay(holder); 这样 MediaPlayer 就没有设置显示器就开始播放了，这样自然看不到画面，而后来系统调用 surfaceCreated 的时候是于事无补的！

这也难怪看到有些人回复说第二次在播放视频的时候就可以，因为前面第一次设置了 holder 嘛！

知道了问题的根本就好办了， 在 surfaceCreated 里设置 holder，然后设置视频数据，然后调用 prepare，这样总是没问题了吧！

下面贴上我封装的一个 VideoPlayer :

public class VideoPlayer implements
            MediaPlayer.OnCompletionListener,
            SurfaceHolder.Callback,
            OnClickListener,
            OnErrorListener,
            OnInfoListener,
            OnTouchListener,
            OnKeyListener,
            MediaPlayer.OnPreparedListener {
    private SurfaceView surfaceView;
    private MediaPlayer mPlayer; // MediaPlayer对象
    private SurfaceHolder mSurfaceHolder; // SurfaceHolder对象
    private ViewGroup viewGroup;
    private GameActivity gameActivity;
    private ImageButton button;

    private boolean surfaceCreated = false;


    public VideoPlayer(GameActivity gameActivity) {
        this.gameActivity = gameActivity;

        LayoutInflater inflater = (LayoutInflater) gameActivity.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
//        LayoutInflater inflater = context.getLayoutInflater();
        viewGroup =  (ViewGroup) inflater.inflate(R.layout.video_player, null);

        button = (ImageButton) viewGroup.findViewById(R.id.button1);
        button.setOnClickListener(this);
        button.setVisibility(View.INVISIBLE);

        surfaceView = (SurfaceView) viewGroup.findViewById(R.id.surfaceView);
        surfaceView.setOnTouchListener(this);
        surfaceView.setOnKeyListener(this);
        surfaceView.setFocusableInTouchMode(true);
        surfaceView.requestFocus();

        mSurfaceHolder = surfaceView.getHolder();
        mSurfaceHolder.addCallback(this); // 设置回调接口
        mSurfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS); // 设置为Buffer类型（播放视频&Camera预览）

        mPlayer = new MediaPlayer();
        mPlayer.setScreenOnWhilePlaying(true);

        mPlayer.setOnPreparedListener(this);
        mPlayer.setOnCompletionListener(this);
        mPlayer.setOnErrorListener(this);
        mPlayer.setOnInfoListener(this);
    }

    public void pause() {
        mPlayer.pause();
    }

    public void resume() {
        mPlayer.start();
    }

    private int resId;
    public void setVideo(int resId) {
        Log.i(PobabyGame.TAG, "== setVideo ! == ");

        this.resId = resId;
        Uri uri = Uri.parse("android.resource://"
                + gameActivity.getPackageName()
                + "/" + resId);

        try {
            mPlayer.setDataSource(gameActivity, uri);
//            mPlayer.prepare();
        } catch (IllegalArgumentException e) {
        } catch (SecurityException e) {
        } catch (IllegalStateException e) {
        } catch (IOException e) {
        }
    }

    public SurfaceView getSurfaceView() {
        return surfaceView;
    }

    public ViewGroup getViewGroup() {
        return viewGroup;
    }

    @Override
    public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
    }

    @Override
    public void surfaceCreated(final SurfaceHolder holder) {
        Log.i(PobabyGame.TAG, "== surfaceCreated ! == " + "holder" + holder.toString() + ", h2" + mSurfaceHolder);

        gameActivity.handler.post(new Runnable() {
            @Override
            public void run() {
                mPlayer.setDisplay(holder); // 指定SurfaceHolder
                surfaceCreated = true;

//                Uri uri = Uri.parse("android.resource://"
//                        + gameActivity.getPackageName()
//                        + "/" + resId);

                try {
//                    mPlayer.setDataSource(gameActivity, uri);
                    mPlayer.prepare();
                } catch (IllegalArgumentException e) {
                } catch (SecurityException e) {
                } catch (IllegalStateException e) {
                } catch (IOException e) {
                }
            }
        });
    }

    @Override
    public void surfaceDestroyed(SurfaceHolder holder) {
        surfaceCreated = false;
    }

    @Override
    public void onPrepared(MediaPlayer player) {
        int wWidth = Gdx.graphics.getWidth();
        int wHeight = Gdx.graphics.getHeight();

        /* 获得视频宽长 */
        int vWidth = mPlayer.getVideoWidth();
        int vHeight = mPlayer.getVideoHeight();

        /* 最适屏幕 */
        float wRatio = (float) vWidth / (float) wWidth; // 宽度比
        float hRatio = (float) vHeight / (float) wHeight; // 高度比
        float ratio = Math.max(wRatio, hRatio); // 较大的比
        vWidth = (int) Math.ceil((float) vWidth / ratio); // 新视频宽度
        vHeight = (int) Math.ceil((float) vHeight / ratio); // 新视频高度

        // 改变SurfaceHolder大小
        mSurfaceHolder.setFixedSize(vWidth, vHeight);
        mPlayer.start();

        gameActivity.gameView.setVisibility(View.INVISIBLE);
    }

    @Override
    public void onCompletion(MediaPlayer mp) {
        gameActivity.videoFinish(resId);
    }

    @Override
    public void onClick(View v) {
        gameActivity.videoFinish(resId);
        mPlayer.release();
    }

    @Override
    public boolean onInfo(MediaPlayer mp, int what, int extra) {
        Log.i(PobabyGame.TAG, String.format("onInfo(%d, %d)", what, extra));
        return true;
    }

    @Override
    public boolean onError(MediaPlayer mp, int what, int extra) {
        Log.e(PobabyGame.TAG, String.format("onError(%d, %d)", what, extra));
        return true;
    }

    @Override
    public boolean onTouch(View v, MotionEvent event) {
        if(event.getAction() == MotionEvent.ACTION_DOWN){
            button.setVisibility(View.VISIBLE);
            return true;
        }

        return false;
    }

    @Override
    public boolean onKey(View v, int keyCode, KeyEvent event) {
        if(event.getAction() == KeyEvent.ACTION_UP && keyCode == KeyEvent.KEYCODE_BACK){
            gameActivity.videoFinish(resId);
            mPlayer.release();
        }

        return true;
    }
}