android SurfaceView中播放视频 按视频的原始比例播放

    OnPreparedListener mediaPlayerOnPreparedListener = new OnPreparedListener() {

        @Override

        public void onPrepared(MediaPlayer arg0) {

            // 首先取得video的宽和高

            int vWidth = mediaPlayer.getVideoWidth();

            int vHeight = mediaPlayer.getVideoHeight();

            // 该LinearLayout的父容器 android:orientation="vertical" 必须

            LinearLayout linearLayout = (LinearLayout) findViewById(R.id.layoutPlay);

            int lw = linearLayout.getWidth();

            int lh = linearLayout.getHeight();

            if (vWidth > lw || vHeight > lh) {

                // 如果video的宽或者高超出了当前屏幕的大小，则要进行缩放

                float wRatio = (float) vWidth / (float) lw;

                float hRatio = (float) vHeight / (float) lh;

                // 选择大的一个进行缩放

                float ratio = Math.max(wRatio, hRatio);

                vWidth = (int) Math.ceil((float) vWidth / ratio);

                vHeight = (int) Math.ceil((float) vHeight / ratio);

                // 设置surfaceView的布局参数

                LinearLayout.LayoutParams lp= new LinearLayout.LayoutParams(vWidth, vHeight);

                lp.gravity = Gravity.CENTER;

                surfaceView.setLayoutParams(lp);

            }

            // 然后开始播放视频

            mediaPlayer.start();

        }

    };