Android video app preview orientation

Nigel January 30, 2016 11:34 am

The android video app preview orientation tutorial describes how to adjust the TextureView width & height dimensions so that they can be compared against the values supplied from the camera sensor.

Get Code

The code to start this tutorial is on github here

https://github.com/mobapptuts/android_camera2_api_video_app.git Tag camera2-video-preview-orientation

or you can run this command

git clone https://github.com/mobapptuts/android_camera2_api_video_app.git –branch camera2-video-preview-orientation

Steps

Setup the ORIENTATIONS array

private static final SparseIntArray ORIENTATIONS = new SparseIntArray();

    static {
        ORIENTATIONS.append(Surface.ROTATION_0, 0);
        ORIENTATIONS.append(Surface.ROTATION_90, 90);
        ORIENTATIONS.append(Surface.ROTATION_180, 180);
        ORIENTATIONS.append(Surface.ROTATION_270, 270);
    }

Calculate the camera sensor orientation in relation to the device orientation

private static int sensorToDeviceRotation(CameraCharacteristics c, int deviceOrientation) {
        int sensorOrientation = c.get(CameraCharacteristics.SENSOR_ORIENTATION);

        // Get device orientation in degrees
        deviceOrientation = ORIENTATIONS.get(deviceOrientation);

        // Calculate desired JPEG orientation relative to camera orientation to make
        // the image upright relative to the device orientation
        return (sensorOrientation + deviceOrientation + 360) % 360;
    }

Calculate the view dimensions required to match the preview & video output sizes

  private void setupCamera(int width, int height) {
        CameraManager cameraManager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);
        try {
            for(String cameraId : cameraManager.getCameraIdList()){
                CameraCharacteristics cameraCharacteristics = cameraManager.getCameraCharacteristics(cameraId);
                if(cameraCharacteristics.get(CameraCharacteristics.LENS_FACING) ==
                        CameraCharacteristics.LENS_FACING_FRONT){
                    continue;
                }
                int deviceOrientation = getWindowManager().getDefaultDisplay().getRotation();
                int totalRotation = sensorToDeviceRotation(cameraCharacteristics, deviceOrientation);
                boolean swapRotation = totalRotation == 90 || totalRotation == 270;
                int rotatedWidth = width;
                int rotatedHeight = height;
                if(swapRotation) {
                    rotatedWidth = height;
                    rotatedHeight = width;
                }
                mCameraId = cameraId;
                return;
            }
        } catch (CameraAccessException e) {
            e.printStackTrace();
        }
    }