Android开发：实时处理摄像头预览帧视频------浅析PreviewCallback,onPreviewFrame，AsyncTask的综合应用(转)

/*自定义的FaceTask类，开启一个线程分析数据*/
private class FaceTask extends AsyncTask<Void, Void, Void>{ private byte[] mData;
//构造函数
PalmTask(byte[] data){
this.mData = data;
} @Override
protected Void doInBackground(Void... params) {
// TODO Auto-generated method stub
Size size = myCamera.getParameters().getPreviewSize(); //获取预览大小
final int w = size.width; //宽度
final int h = size.height;
final YuvImage image = new YuvImage(mData, ImageFormat.NV21, w, h, null);
ByteArrayOutputStream os = new ByteArrayOutputStream(mData.length);
if(!image.compressToJpeg(new Rect(0, 0, w, h), 100, os)){
return null;
}
byte[] tmp = os.toByteArray();
Bitmap bmp = BitmapFactory.decodeByteArray(tmp, 0,tmp.length);
doSomethingNeeded(bmp); //自己定义的实时分析预览帧视频的算法 return null;
} }

onPreviewFrame()里可以这样写： /*获取预览帧视频*/
public void onPreviewFrame(byte[] data, Camera camera) {
// TODO Auto-generated method stub
if(null != mFaceTask){
switch(mFaceTask.getStatus()){
case RUNNING:
return;
case PENDING:
mFaceTask.cancel(false);
break;
}
}
mFaceTask = new PalmTask(data);
mFaceTask.execute((Void)null); }

//自动聚焦变量回调
myAutoFocusCallback = new AutoFocusCallback() { public void onAutoFocus(boolean success, Camera camera) {
// TODO Auto-generated method stub
if(success)//success表示对焦成功
{
Log.i(tag, "myAutoFocusCallback: success...");
myCamera.setOneShotPreviewCallback(RectPhoto.this); }
else
{
//未对焦成功 Log.i(tag, "myAutoFocusCallback: 失败了..."); //这里也可以加上myCamera.autoFocus(myAutoFocusCallback)，如果聚焦失败就再次启动聚焦。
} }
};

class ScanThread implements Runnable{ public void run() {
// TODO Auto-generated method stub
while(!Thread.currentThread().isInterrupted()){
try {
if(null != myCamera && isPreview)
{&nbsp;&nbsp;&nbsp;&nbsp;
//myCamera.autoFocus(myAutoFocusCallback);
myCamera.setOneShotPreviewCallback(RectPhoto.this);
Log.i(tag, "setOneShotPreview...");
}
Thread.sleep(1500);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
Thread.currentThread().interrupt();
}
} } }