Android 5.0 Wrong crop regions on preview surface and captured still image

Question

I'm trying to get digital zoomed frame on Android 5.0 with camera2 interface. Appropriate doc for that functionality is developer.android.com/camera2/captureRequest

Surface used in my application:

• SurafaceView (1920x1080, 16:9 aspect ratio)
• ImageReader (3264x2448, 4:3 aspect ratio)

Camera's sensor size is 3280x2464 (4:3 aspect ratio)

Crop region which I want to get from sensor is:

Rect zoomCropPreview = new Rect(1094, 822, 2186, 1642); //(1092x820, 4:3 aspect ratio)

I set this Rect as parameter for preview request:

previewRequestBuilder.set(CaptureRequest.SCALER_CROP_REGION, zoomCropPreview);
captureSession.setRepeatingRequest(previewRequestBuilder.build(), null, null);

And to take still image:

stillRequestBuilder.set(CaptureRequest.SCALER_CROP_REGION, zoomCropPreview);

captureSession.capture(stillRequestBuilder.build(), new captureListener() , null);

Expected results:

• Coz crop rectangle is 4:3 ratio, then preview should be cropped vertically (letterbox)
• Still image should be exact crop region.
• Both preview and still image should be centered on the same point of scene, and should differ only in vertical edges.

Real result:

• Preview and still image point on different scene which seems to be moved vertically. Look at attach images.

What am I doing wrong?

Answer 1

Fixed! General idea is to calculate crop region for preview and still images separately.

1) Calculate crop region for still image as in initial post (use 4:3 rectangle)

2) For preview take above crop region (4:3) and reduce vertical size to get 16:9 rectangle.