Android Camera ohne Preview (Service)

public class VideoRecorder{
    private Camera camera = null;
    private MediaRecorder mediaRecorder = null;


    public void onDestroy()
    {
        //MUST CALLED ON DESTROY
resetRecorder();
}


    public void start()
    {
setupMediaRecorder();
mediaRecorder.start();




}




    public void setupMediaRecorder()
    {


        try {
        mediaRecorder = new MediaRecorder();
camera = Camera.open();
} catch (Exception e) {
            e.printStackTrace();
}


        camera.unlock();
          //------------------------------------------------------------------//
         //  set Preview Display()                                           //
        //------------------------------------------------------------------//
mediaRecorder.setCamera(camera);
mediaRecorder.setAudioSource(MediaRecorder.AudioSource.CAMCORDER);
mediaRecorder.setVideoSource(MediaRecorder.VideoSource.CAMERA);
//SETTINGS
mediaRecorder.setProfile(CamcorderProfile.get(CamcorderProfile.QUALITY_HIGH));
mediaRecorder.setOrientationHint(90);
//SETTINGS
File file = new File(Environment.getExternalStorageDirectory()+"/Video/");
        if(!file.exists())
            file.mkdirs();
mediaRecorder.setOutputFile(Environment.getExternalStorageDirectory() + "/Video/Video " + DateFormat.format("yyyy-MM-dd_kk-mm-ss", new Date().getTime()) + ".mp4");
        try {
            mediaRecorder.prepare();
} catch (IOException e) {
            e.printStackTrace();
}
    }


    public void stop()
    {
        try {
            mediaRecorder.stop();
}catch (Exception e)
        {
            e.printStackTrace();
}
        resetRecorder();
}


    private void resetRecorder()
    {
        //RESET RECORDER AFTER RECORDING
mediaRecorder.reset();
mediaRecorder.release();
camera.release();
}


}