Camera onPreviewFrame not called

Question

when using the Camera.PreviewCallback implementation the onPreviewFrame is called without problem after initializing camera and starting preview (Camera.startPrevew()). The

Answer 1

I had a similar problem; see

setOneShotPreviewCallback not hitting onPreviewFrame() in callback

What I discovered was that after calling Camera#unlock() to prepare the MediaRecorder, it was necessary to call Camera#reconnect() before setting the preview callback. This is because Camera.unlock() detaches the camera from the process to let the MediaRecorder connect to it.

http://developer.android.com/reference/android/hardware/Camera.html#unlock()

In my investigations I also discovered that if you set any preview callbacks using other methods than the one shot method, you have to reset all of these after calling Camera#reconnect() as well. So, briefly:

mCamera.unlock();
//set up MediaRecorder
mCamera.reconnect();
mCamera.setPreviewCallback(mCallback);
//or whatever callback method you want to use
//and even if you've set this callback already

I hope that helps!