VideoView与视频比例缩放:
以前在论坛上也看到有人问过如何实现视频按比例缩放的问题。的确,如果仅仅使用VideoView可能达不到我们想要达到的效果。这就需要我们对VideoView做一些改动,简单的说就是另外写一个类似VideoView的类出来(庆幸Android是开源的)。我们可以很方便的获得VideoView的源代码,最简单的方法是直接在GoogleCodeSearch上找“VideoView.java”。所以重写VideoView的过程其实只是在原来的基础上进行一些修改而已,并非一个很麻烦的工作。为什么Android自带的VideoView会保持视频的长宽比而不能让我们很方便的自定义比例呢?我猜想可能Google做Android也是一个很仓促的工程,许多代码并没有考虑得太成熟。VideoView的源码中有这样一段代码:
1 @Override
2 protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
3 //Log.i(“@@@@“, “onMeasure”);
4 int width = getDefaultSize(mVideoWidth, widthMeasureSpec);
5 int height = getDefaultSize(mVideoHeight, heightMeasureSpec);
6 if (mVideoWidth > 0 && mVideoHeight > 0) {
7 if ( mVideoWidth * height > width * mVideoHeight ) {
8 //Log.i(“@@@“, “image too tall, correcting”);
9 height = width * mVideoHeight / mVideoWidth;
10 } else if ( mVideoWidth * height < width * mVideoHeight ) {
11 //Log.i(“@@@“, “image too wide, correcting”);
12 width = height * mVideoWidth / mVideoHeight;
13 } else {
14 //Log.i(“@@@“, “aspect ratio is correct: " +
15 //width+“/“+height+“=“+
16 //mVideoWidth+“/“+mVideoHeight);
17 }
18 }
19 //Log.i(“@@@@@@@@@@“, “setting size: " + width + 'x' + height);
20 setMeasuredDimension(width, height);
21 }
22
这就是为什么长宽比不能改变的原因了。因为在OnMeasure的时候,就对这个长宽比进行了处理。 我们把其中处理的代码屏蔽掉,视频大小就可以随着VideoView的长宽改变而改变了。
1 @Override
2 protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
3 //Log.i(“@@@@“, “onMeasure”);
4 int width = getDefaultSize(mVideoWidth, widthMeasureSpec);
5 int height = getDefaultSize(mVideoHeight, heightMeasureSpec);
6 /*//if (mVideoWidth > 0 && mVideoHeight > 0) {
7 if ( mVideoWidth * height > width * mVideoHeight ) {
8 //Log.i(“@@@“, “image too tall, correcting”);
9 height = width * mVideoHeight / mVideoWidth;
10 } else if ( mVideoWidth * height < width * mVideoHeight ) {
11 //Log.i(“@@@“, “image too wide, correcting”);
12 width = height * mVideoWidth / mVideoHeight;
13 } else {
14 //Log.i(“@@@“, “aspect ratio is correct: " +
15 //width+“/“+height+“=“+
16 //mVideoWidth+“/“+mVideoHeight);
17 }
18 }*/
19 //Log.i(“@@@@@@@@@@“, “setting size: " + width + 'x' + height);
20 setMeasuredDimension(width,height);
21 }
自定义VideoView
public class CustomVideoView extends VideoView {
private int mVideoWidth; private int mVideoHeight; public CustomVideoView(Context context) { super(context); // TODO Auto-generated constructor stub } public CustomVideoView(Context context, AttributeSet attrs) { super(context, attrs); // TODO Auto-generated constructor stub } public CustomVideoView(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); // TODO Auto-generated constructor stub } @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { // TODO Auto-generated method stub // Log.i("@@@@", "onMeasure"); //下面的代码是让视频的播放的长宽是根据你设置的参数来决定 int width = getDefaultSize(mVideoWidth, widthMeasureSpec); int height = getDefaultSize(mVideoHeight, heightMeasureSpec); setMeasuredDimension(width, height); }
}
MediaController controller = new MediaController(this);
mVideoView = (CustomVideoView)findViewById(R.id.videoView1); mVideoView.setMediaController(controller); mVideoView.setVideoPath(mVideoPath);