我想使用服务打开设备的前置摄像头以获得连续帧并实时处理它们。我可以使用MediaRecorder执行此操作，如以下代码所示：
public class BackgroundService extends Service implements SurfaceHolder.Callback {
private int NOTIFICATION_ID= 1;
MediaRecorder mediaRecorder;
private static final String TAG = "OCVSample::Activity";
// Binder given to clients
private final IBinder mBinder = new LocalBinder();
public class LocalBinder extends Binder {
BackgroundService getService() {
// Return this instance of this service so clients can call public methods
return BackgroundService.this;
}
}//end inner class that returns an instance of the service.
@Override
public IBinder onBind(Intent intent) {
return mBinder;
}//end onBind.
private WindowManager windowManager;
private SurfaceView surfaceView;
private Camera camera = null;
@Override
public void onCreate() {
// Start foreground service to avoid unexpected kill
startForeground(NOTIFICATION_ID, buildNotification());
// Create new SurfaceView, set its size to 1x1, move it to the top left corner and set this service as a callback
windowManager = (WindowManager) this.getSystemService(Context.WINDOW_SERVICE);
surfaceView = new SurfaceView(this);
WindowManager.LayoutParams layoutParams = new WindowManager.LayoutParams(
100, 100,
WindowManager.LayoutParams.TYPE_SYSTEM_OVERLAY,
WindowManager.LayoutParams.FLAG_WATCH_OUTSIDE_TOUCH,
PixelFormat.TRANSLUCENT
);
Log.i(TAG, "100 x 100 executed");
layoutParams.gravity = Gravity.LEFT | Gravity.TOP;
windowManager.addView(surfaceView, layoutParams);
surfaceView.getHolder().addCallback(this);
}
// Method called right after Surface created (initializing and starting MediaRecorder)
@Override
public void surfaceCreated(SurfaceHolder surfaceHolder) {
Log.i(TAG, "surfaceCreated method");
camera = Camera.open(1);
camera.unlock();
mediaRecorder = new MediaRecorder();
mediaRecorder.setPreviewDisplay(surfaceHolder.getSurface());
mediaRecorder.setCamera(camera);
mediaRecorder.setAudioSource(MediaRecorder.AudioSource.CAMCORDER);
mediaRecorder.setVideoSource(MediaRecorder.VideoSource.CAMERA);
mediaRecorder.setProfile(CamcorderProfile.get(CamcorderProfile.QUALITY_HIGH));
mediaRecorder.setOutputFile(
Environment.getExternalStorageDirectory()+"/"+
DateFormat.format("yyyy-MM-dd_kk-mm-ss", new Date().getTime())+
".mp4"
);
try { mediaRecorder.prepare(); } catch (Exception e) {}
mediaRecorder.start();
}
// Stop recording and remove SurfaceView
@Override
public void onDestroy() {
Log.i(TAG, "surfaceDestroyed method");
camera.lock();
camera.release();
windowManager.removeView(surfaceView);
}
@Override
public void surfaceChanged(SurfaceHolder surfaceHolder, int format, int width, int height) {}
@Override
public void surfaceDestroyed(SurfaceHolder surfaceHolder) {
}
private Notification buildNotification () {
NotificationCompat.Builder notificationBuilder=new NotificationCompat.Builder(this);
notificationBuilder.setOngoing(true); //this notification should be ongoing
notificationBuilder.setContentTitle(getString(R.string.notification_title))
.setContentText(getString (R.string.notification_text_and_ticker))
.setSmallIcon(R.drawable.vecsat_logo)
.setTicker(getString(R.string.notification_text_and_ticker));
return(notificationBuilder.build());
}
}//end service.
但这记录了视频，我不想要那样。我只是想打开相机来实时获取帧。我试图直接打开它而不使用MediaRecorder，但它的视图没有显示，我只是更改了surfaceCreated方法中的代码部分，如下所示：
@Override
public void surfaceCreated(SurfaceHolder surfaceHolder) {
Log.i(TAG, "surfaceCreated method");
try {
camera = Camera.open(1);
camera.setPreviewDisplay(surfaceView.getHolder());
camera.unlock();
}
catch (IOException e){
}
}
有人可以告诉我如何在没有录音的情况下打开相机吗？
感谢。