Android Camera - Sometimes when i take photos, the app freezes and the camera is non-usable

Question

I have built an application which takes photos when you touch the preview. I can take many photos, but sometimes when i touch the preview to take a photo, there is no shutter sound and the whole application freezes. Moreover, after that, if i try to launch launch the built-in camera application, i get a message that the camera can't be used.

I don't know the reason for that behavior, it happens randomly and when it happens i must restart the device (Samsung Galaxy S) to be able to use the camera again.

In the DDM, after the crash i can see the following line: keyDispatchingTimedOut

Here is the relevant code: CameraActivity Class:

public class CameraActivity extends Activity {
  private static final String TAG = "CameraDemo";
  Preview preview;

  public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    preview = new Preview(this);
    ((FrameLayout) findViewById(R.id.preview)).addView(preview);
    ((FrameLayout) findViewById(R.id.preview)).setOnTouchListener(preview); 

    Log.d(TAG, "Camera Activity Created.");

  }
}

Preview Class:

    class Preview extends SurfaceView implements SurfaceHolder.Callback, OnTouchListener {
    private static final String TAG = "Preview";

    SurfaceHolder mHolder;
    public Camera camera;
    Context ctx;
    boolean previewing = false;

    Preview(Context context) {
        super(context);
        ctx = context;
        // Install a SurfaceHolder.Callback so we get notified when the
        // underlying surface is created and destroyed.
        mHolder = getHolder();
        mHolder.addCallback(this);
        mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
    }


    // Called once the holder is ready
    public void surfaceCreated(SurfaceHolder holder) {
        // The Surface has been created, acquire the camera and tell it where
        // to draw.
        camera = Camera.open();
    }

    // Called when the holder is destroyed
    public void surfaceDestroyed(SurfaceHolder holder) {

        if (camera != null) {
            camera.setPreviewCallback(null);
            camera.stopPreview();  
            camera.release();
            camera = null;
        }

        previewing = false;
    }

    // Called when holder has changed
    public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {

        if(previewing){
             camera.stopPreview();
             previewing = false;
        }

        if (camera != null){
            try {

                camera.setDisplayOrientation(90);
                camera.setPreviewDisplay(holder);
                camera.setPreviewCallback(new PreviewCallback() {
                    // Called for each frame previewed
                    public void onPreviewFrame(byte[] data, Camera camera) {
                        Log.d(TAG, "onPreviewFrame called at: " + System.currentTimeMillis());  
                        Preview.this.invalidate();
                    }
                });
                camera.startPreview();
                previewing = true;
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    }

    public boolean onTouch(View v, MotionEvent event) {
        camera.takePicture(shutterCallback, rawCallback, jpegCallback);
        return false;
    }


    // Called when shutter is opened
    ShutterCallback shutterCallback = new ShutterCallback() {
        public void onShutter() {
            Log.d(TAG, "onShutter'd");
        }
    };

    // Handles data for raw picture
    PictureCallback rawCallback = new PictureCallback() {
        public void onPictureTaken(byte[] data, Camera camera) {
            Log.d(TAG, "onPictureTaken - raw");
        }
    };

    // Handles data for jpeg picture
    PictureCallback jpegCallback = new PictureCallback() {

        public void onPictureTaken(byte[] data, Camera camera) {
            FileOutputStream outStream = null;
            try {
                // Write to SD Card
                outStream = new FileOutputStream(String.format("/sdcard/TVguide/Detection/detected.jpg", System.currentTimeMillis())); // <9>
                outStream.write(data);
                outStream.close();
                Log.d(TAG, "onPictureTaken - wrote bytes: " + data.length);
            } catch (FileNotFoundException e) { // <10>
                //Toast.makeText(ctx, "Exception #2", Toast.LENGTH_LONG).show();
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            } finally {}
            Log.d(TAG, "onPictureTaken - jpeg");
            Toast.makeText(ctx, "SAVED", Toast.LENGTH_SHORT).show();

            camera.startPreview();
        }
    };

}

Please help, i am trying a few days to understand where the problem is with no success

Eyal

Answer 1

I just run into this issue when testing my application on a Samsung Galaxy SII. You just have to remove the preview callback before taking the picture:

mCamera.setPreviewCallback(null);
mCamera.takePicture(null, null, mPictureCallback);