How to chang focus by code in camera2 of android?

Question

I want to implement a function in a camera app in android that I can click a button than get 2 photo with different focus(not a manual focus function).

I've complete all except that my focus change part can't run, I can't find the cause, and try to analysis:

Try 1: I use the focus control code in this and this to change the focus, but it didn't work.

1. The cammera builder set part:

   private CaptureRequest.Builder initDngBuilder() {
       CaptureRequest.Builder captureBuilder = null;
       try {
           captureBuilder = mCameraSession.getDevice().createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW);
   
           captureBuilder.addTarget(mImageReader.getSurface());
           captureBuilder.addTarget(surface);
           // Required for RAW capture
           captureBuilder.set(CaptureRequest.STATISTICS_LENS_SHADING_MAP_MODE, CaptureRequest.STATISTICS_LENS_SHADING_MAP_MODE_ON);
           captureBuilder.set(CaptureRequest.CONTROL_AE_MODE, CaptureRequest.CONTROL_AE_MODE_OFF);
           captureBuilder.set(CaptureRequest.CONTROL_AF_MODE, CameraMetadata.CONTROL_AF_MODE_OFF);
           captureBuilder.set(CaptureRequest.LENS_FOCUS_DISTANCE, 0.1f);
           captureBuilder.set(CaptureRequest.SENSOR_EXPOSURE_TIME, (long) ((214735991 - 13231) / 2));
           captureBuilder.set(CaptureRequest.CONTROL_AE_EXPOSURE_COMPENSATION, 0);
           captureBuilder.set(CaptureRequest.SENSOR_SENSITIVITY, (10000 - 100) / 2);
           captureBuilder.set(CaptureRequest.JPEG_ORIENTATION, 90);
           CameraManager cameraManager = (CameraManager) getActivity().getSystemService(Context.CAMERA_SERVICE);
           String cameraid = CameraCharacteristics.LENS_FACING_FRONT + "";
           CameraCharacteristics cameraCharacteristics = cameraManager.getCameraCharacteristics(cameraid);
           Range<Integer> fps[] = cameraCharacteristics.get(CameraCharacteristics.CONTROL_AE_AVAILABLE_TARGET_FPS_RANGES);
           captureBuilder.set(CaptureRequest.CONTROL_AE_TARGET_FPS_RANGE, fps[fps.length - 1]);
       } catch (CameraAccessException e) {
           Toast.makeText(getActivity(), "reject", Toast.LENGTH_SHORT).show();
       } catch (NullPointerException e) {
           Toast.makeText(getActivity(), "fail", Toast.LENGTH_SHORT).show();
       }
       return captureBuilder;}
   private CaptureRequest.Builder initDngBuilder2() {
   CaptureRequest.Builder captureBuilder = null;
   try {
       captureBuilder = mCameraSession.getDevice().createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW);
       captureBuilder.addTarget(mImageReader.getSurface());
       captureBuilder.addTarget(surface);
       // Required for RAW capture
       captureBuilder.set(CaptureRequest.STATISTICS_LENS_SHADING_MAP_MODE, CaptureRequest.STATISTICS_LENS_SHADING_MAP_MODE_ON);
       captureBuilder.set(CaptureRequest.CONTROL_AE_MODE, CaptureRequest.CONTROL_AE_MODE_OFF);
       captureBuilder.set(CaptureRequest.CONTROL_AF_MODE, CameraMetadata.CONTROL_AF_MODE_OFF);
       captureBuilder.set(CaptureRequest.LENS_FOCUS_DISTANCE, 100.0f);
       captureBuilder.set(CaptureRequest.SENSOR_EXPOSURE_TIME, (long) ((214735991 - 13231) / 2));
       captureBuilder.set(CaptureRequest.CONTROL_AE_EXPOSURE_COMPENSATION, 0);
       captureBuilder.set(CaptureRequest.SENSOR_SENSITIVITY, (10000 - 100) / 2);
       captureBuilder.set(CaptureRequest.JPEG_ORIENTATION, 90);
       CameraManager cameraManager = (CameraManager) getActivity().getSystemService(Context.CAMERA_SERVICE);
       String cameraid = CameraCharacteristics.LENS_FACING_FRONT + "";
       CameraCharacteristics cameraCharacteristics = cameraManager.getCameraCharacteristics(cameraid);
       Range<Integer> fps[] = cameraCharacteristics.get(CameraCharacteristics.CONTROL_AE_AVAILABLE_TARGET_FPS_RANGES);
       captureBuilder.set(CaptureRequest.CONTROL_AE_TARGET_FPS_RANGE, fps[fps.length - 1]);
   } catch (CameraAccessException e) {
       Toast.makeText(getActivity(), "reject", Toast.LENGTH_SHORT).show();
   } catch (NullPointerException e) {
       Toast.makeText(getActivity(), "fail", Toast.LENGTH_SHORT).show();
   }
   return captureBuilder;
   

   }

2. The click listener part:

   private View.OnClickListener picOnClickListener = new View.OnClickListener() {
   @Override
   public void onClick(View view) {
       try {
           mCameraSession.capture(initDngBuilder().build(), null, mHandler);
           mCameraSession.capture(initDngBuilder2().build(), null, mHandler);
       } catch (CameraAccessException e) {
           e.printStackTrace();
       }
   }};
   

Try 2: I want to figure out if my android device don't have the ability(I consider that point because: https://stackoverflow.com/a/42912408/9521891), so I use:

int[] ints = mCameraCharacteristics.get(CameraCharacteristics.REQUEST_AVAILABLE_CAPABILITIES);

for (int i = 0; i < ints.length; i++){
    Log.d(TAG, ints[i] + ",");
}

And I got only :" 0, ". Does it means the device don't have the ablility 'MANUAL_SENSOR'?

Answer 1

Yes, if the contents of REQUEST_AVAILABLE_CAPABILITIES only contains BACKWARD_COMPATIBLE (0), then the device does not support MANUAL_SENSOR.

Therefore, setting the LENS_FOCUS_DISTANCE to any value besides 0.0f (infinity focus) is not supported.