A enhance SurfaceView which support scale content size according to aspect ratio.

VideoSurfaceView.java

public class VideoSurfaceView extends SurfaceView implements MediaPlayer.OnVideoSizeChangedListener {
    private int mVideoWidth;
    private int mVideoHeight;

    public VideoSurfaceView(Context context) {
        super(context);
    }

    public VideoSurfaceView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public VideoSurfaceView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    /**
     * Set video size.
     *
     * @see MediaPlayer#getVideoWidth()
     * @see MediaPlayer#getVideoHeight()
     */
    public void setVideoSize(int videoWidth, int videoHeight) {
        mVideoWidth = videoWidth;
        mVideoHeight = videoHeight;
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        //Log.i("@@@@", "onMeasure(" + MeasureSpec.toString(widthMeasureSpec) + ", "
        //        + MeasureSpec.toString(heightMeasureSpec) + ")");

        int width = getDefaultSize(mVideoWidth, widthMeasureSpec);
        int height = getDefaultSize(mVideoHeight, heightMeasureSpec);
        if (mVideoWidth > 0 && mVideoHeight > 0) {

            int widthSpecMode = MeasureSpec.getMode(widthMeasureSpec);
            int widthSpecSize = MeasureSpec.getSize(widthMeasureSpec);
            int heightSpecMode = MeasureSpec.getMode(heightMeasureSpec);
            int heightSpecSize = MeasureSpec.getSize(heightMeasureSpec);

            if (widthSpecMode == MeasureSpec.EXACTLY && heightSpecMode == MeasureSpec.EXACTLY) {
                // the size is fixed
                width = widthSpecSize;
                height = heightSpecSize;

                // for compatibility, we adjust size based on aspect ratio
                if (mVideoWidth * height < width * mVideoHeight) {
                    //Log.i("@@@", "image too wide, correcting");
                    width = height * mVideoWidth / mVideoHeight;
                } else if (mVideoWidth * height > width * mVideoHeight) {
                    //Log.i("@@@", "image too tall, correcting");
                    height = width * mVideoHeight / mVideoWidth;
                }
            } else if (widthSpecMode == MeasureSpec.EXACTLY) {
                // only the width is fixed, adjust the height to match aspect ratio if possible
                width = widthSpecSize;
                height = width * mVideoHeight / mVideoWidth;
                if (heightSpecMode == MeasureSpec.AT_MOST && height > heightSpecSize) {
                    // couldn't match aspect ratio within the constraints
                    height = heightSpecSize;
                }
            } else if (heightSpecMode == MeasureSpec.EXACTLY) {
                // only the height is fixed, adjust the width to match aspect ratio if possible
                height = heightSpecSize;
                width = height * mVideoWidth / mVideoHeight;
                if (widthSpecMode == MeasureSpec.AT_MOST && width > widthSpecSize) {
                    // couldn't match aspect ratio within the constraints
                    width = widthSpecSize;
                }
            } else {
                // neither the width nor the height are fixed, try to use actual video size
                width = mVideoWidth;
                height = mVideoHeight;
                if (heightSpecMode == MeasureSpec.AT_MOST && height > heightSpecSize) {
                    // too tall, decrease both width and height
                    height = heightSpecSize;
                    width = height * mVideoWidth / mVideoHeight;
                }
                if (widthSpecMode == MeasureSpec.AT_MOST && width > widthSpecSize) {
                    // too wide, decrease both width and height
                    width = widthSpecSize;
                    height = width * mVideoHeight / mVideoWidth;
                }
            }
        } else {
            // no size yet, just adopt the given spec sizes
        }
        setMeasuredDimension(width, height);
    }

    @Override
    public void onVideoSizeChanged(MediaPlayer mp, int width, int height) {
        mVideoWidth = mp.getVideoWidth();
        mVideoHeight = mp.getVideoHeight();
        if (mVideoWidth != 0 && mVideoHeight != 0) {
            getHolder().setFixedSize(mVideoWidth, mVideoHeight);
            requestLayout();
        }
    }
}