android - PictureCallback.onPictureTaken never called

Question

I am writing an application that needs pictures taken with the camera. The problem occurs when I try to take an actual picture. Here's the code that is troubling me:

    final ShutterCallback shutterCallback = new ShutterCallback() {
        @Override
        public void onShutter() {
            Log.d(TAG, "onShutter");
        }
    };

    final PictureCallback callback = new PictureCallback() {

        @Override
        public void onPictureTaken(byte[] data, Camera camera) {
            Log.d(TAG, "onPictureTaken - jpeg");
            try {
                //async task for storing the photo
                new SavePhotoTask(CameraView.this.ctx, data).execute();
            } catch (final SavePhotoException e) {
                //some exceptionhandling
            }
        }
    };
    this.camera = Camera.open();
    this.camera.setPreviewDisplay(surfaceHolder);
    final Camera.Parameters parameters = findBestParameters(w, h);
    this.camera.setParameters(parameters);
    this.camera.startPreview();
    Log.d(TAG, "takePicture now!");
    this.camera.takePicture(shutterCallback, null, callback);

On the emulator it seems to work out but on my phone (Motorola Defy - android 2.1).

The actual problem: on the phone the picturecallback is never happening "onPictureTaken" gets never called. The Shuttercallback is executed but the other is not (and I tried with raw instead of jpeg, same thing).

Does anyone know this problem? I just don't see where the difference lies to the emulator right now. I appreciate your help.

Answer 1

I finally went and debugged the problem. All of a sudden it worked, because debugging is much slower: It's a timing problem. The callback takes some time to be called. While debugging the phone had enough time to finish taking the picture ...

Also don't go calling Camera.stopPreview() and Camera.release() too early.