Front Camera in Camera2 not capturing image

Question

I have the code for the Camera2 from https://github.com/googlesamples/android-Camera2Basic.

The problem i\'m facing is that when i turn to my Front Camera, i cannot capt

Answer 1

The problem is that many front-facing cameras have a fixed focus distance. So after the autofocus trigger in lockFocus() the autofocus state (CONTROL_AF_STATE) remains INACTIVE and the autofocus trigger does nothing.

So in order to make it work you need to check whether autofocus is supported or not. To do so, add the following to setUpCameraOutputs():

int[] afAvailableModes = characteristics.get(CameraCharacteristics.CONTROL_AF_AVAILABLE_MODES);

if (afAvailableModes.length == 0 || (afAvailableModes.length == 1
        && afAvailableModes[0] == CameraMetadata.CONTROL_AF_MODE_OFF)) {
    mAutoFocusSupported = false;
} else {
    mAutoFocusSupported = true;
}

Finally don't lock focus if its not supported when you want to take a picture:

private void takePicture() {
    if (mAutoFocusSupported) {
        lockFocus();
    } else {
        captureStillPicture();
    }
}

Answer 2

@ArvindSingh's solution is not the best one, because you would also disable the focus functionality for the back camera. A better solution would be to do a camera facing check inside the takePicture like that:

private void takePicture() {
    if (CameraCharacteristics.LENS_FACING_FRONT == mSelectedFacing) {
        // front camera selected, so take a picture without focus
        captureStillPicture();
    } else {
        // back camera selected, trigger the focus before creating an image
        lockFocus();
    }
}

For this solution you only need to save the current used facing somewhere like here in mSelectedFacing

Answer 3

Plz try this code for capture

case STATE_WAITING_LOCK: {
                Integer afState = result.get(CaptureResult.CONTROL_AF_STATE);
                if (afState == null) {
                    captureStillPicture();
                } else if (CaptureResult.CONTROL_AF_STATE_FOCUSED_LOCKED == afState ||
                        CaptureResult.CONTROL_AF_STATE_NOT_FOCUSED_LOCKED == afState ||
                         CaptureResult.CONTROL_AF_STATE_INACTIVE == afState /*add this*/) {
                    // CONTROL_AE_STATE can be null on some devices
                    Integer aeState = result.get(CaptureResult.CONTROL_AE_STATE);
                    if (aeState == null || aeState == CaptureResult.CONTROL_AE_STATE_CONVERGED) {
                        mState = STATE_PICTURE_TAKEN;
                        captureStillPicture();
                    } else {
                        runPrecaptureSequence();
                    }
                }
                break;
            }

Answer 4

For Camera2 Api, Google's example for video works great for both front and back camera, but for Image capturing, Google's example works only for back camera and not for front camera.
Solution which works for me is

In lockFocus() method, replace line

mCaptureSession.capture(mPreviewRequestBuilder.build(),
                                                  mCaptureCallback, mBackgroundHandler);

with

captureStillPicture();

Hope this will help!!

Answer 5

In lockFocus() method, replace line

mCaptureSession.capture(mPreviewRequestBuilder.build(),
                                              mCaptureCallback,    mBackgroundHandler);

with

captureStillPicture();

And to prevent Unwanted orientation you can use

/** * Conversion from screen rotation to JPEG orientation. */

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