How to access external USB cameras using Android cameraX?

Question

I was following this codelab to create a cameraX application .

It's working fine in my phone . But the app I am developing is for an android media player.Which doesn't have any inbuilt camera , only an external usb cam is attached .

This is my code to start the camera.

private void startCamera() {
    ListenableFuture<ProcessCameraProvider> cameraProviderFuture = ProcessCameraProvider.getInstance(this);
    Preview preview = new Preview.Builder().build();
    preview.setSurfaceProvider(viewFinder.getSurfaceProvider());
    imageCapture = new ImageCapture.Builder().build();
    cameraProviderFuture.addListener(() -> {
                try {
                    ProcessCameraProvider cameraProvider = cameraProviderFuture.get();
                    cameraProvider.unbindAll();
                    cameraProvider.bindToLifecycle(this, CameraSelector.DEFAULT_BACK_CAMERA,preview,imageCapture);
                } catch (ExecutionException e) {
                    e.printStackTrace();
                    Toast.makeText(this, e.getMessage(), Toast.LENGTH_SHORT).show();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                    Toast.makeText(this, e.getMessage(), Toast.LENGTH_SHORT).show();
                }
                catch (IllegalArgumentException e){
                    Toast.makeText(this, e.getMessage(), Toast.LENGTH_SHORT).show();
                }
            }, ContextCompat.getMainExecutor(this)
    );


}

it's throwing IllegalArgumentException saying no camera connected .

in cameraProvider.bindToLifecycle(this, CameraSelector.DEFAULT_BACK_CAMERA,preview,imageCapture);

only CameraSelector.DEFAULT_FRONT_CAMERA and CameraSelector.DEFAULT_BACK_CAMERA available.

How to access an external camera ?

Open Camera app from play store is working fine .

Answer 1

I have resolve the issue, you can find my project code in this site:

reference JavaApplication Module

I create a filter:

@SuppressLint("UnsafeExperimentalUsageError")
class MyCameraFilter implements CameraFilter {

    @SuppressLint("RestrictedApi")
    @NonNull
    @Override
    public LinkedHashSet<Camera> filter(@NonNull LinkedHashSet<Camera> cameras) {
        Log.i(TAG, "cameras size: " + cameras.size());
        Iterator<Camera> cameraIterator = cameras.iterator();
        Camera camera = null;
        while (cameraIterator.hasNext()) {
            camera = cameraIterator.next();
            String getImplementationType = camera.getCameraInfo().getImplementationType();
            Log.i(TAG, "getImplementationType: " + getImplementationType);
        }
        LinkedHashSet linkedHashSet = new LinkedHashSet<>();
        linkedHashSet.add(camera); // 最后一个camera
        return linkedHashSet;
    }
}

and pass it to CameraSelector:

cameraSelector = new CameraSelector.Builder().addCameraFilter(new MyCameraFilter()).build();

Now i can access usb camera. My develop android chip is Android API 11 The log "cameras size: " will tell you how many cameras connected to the usb. Default select the last camera.