Android CameraX - Get camera info (view angle, preview image size)

user_10085293 0
Viewed 2803

I'm trying to switch from old Android camera API to new CameraX API. I'm using preview mode for an Augmented Reality App and I need to get some info like angle of view and size on my camera used by the Preview.

This is my code so far:

PreviewConfig config = new PreviewConfig.Builder()
                .setLensFacing(CameraX.LensFacing.BACK)
                .setTargetResolution(new Size(dsiWidth, dsiHeight))
                .build();
Preview preview = new Preview(config);
preview.setOnPreviewOutputUpdateListener(new Preview.OnPreviewOutputUpdateListener() {
            @Override
            public void onUpdated(Preview.PreviewOutput output) {
                tvCameraView.setSurfaceTexture(output.getSurfaceTexture());
            }
        });
CameraX.bindToLifecycle(this, preview);

This works so far. But how do I get information on the camera used by the Preview? Thanks a lot in advance!

android-camerax android
1 Answers

When you use the "androidx.camera:camera-camera2:1.0.0-alpha02" dependency you can have a look at the class Camera2CameraFactory. There you can see how the front and back facing camera is determined.

    @Override
    public Set<String> getAvailableCameraIds() throws CameraInfoUnavailableException {
        List<String> camerasList = null;
        try {
            camerasList = Arrays.asList(mCameraManager.getCameraIdList());
        } catch (CameraAccessException e) {
            throw new CameraInfoUnavailableException(
                    "Unable to retrieve list of cameras on device.", e);
        }
        // Use a LinkedHashSet to preserve order
        return new LinkedHashSet<>(camerasList);
    }

    @Nullable
    @Override
    public String cameraIdForLensFacing(LensFacing lensFacing)
            throws CameraInfoUnavailableException {
        Set<String> cameraIds = getAvailableCameraIds();

        // Convert to from CameraX enum to Camera2 CameraMetadata
        Integer lensFacingInteger = -1;
        switch (lensFacing) {
            case BACK:
                lensFacingInteger = CameraMetadata.LENS_FACING_BACK;
                break;
            case FRONT:
                lensFacingInteger = CameraMetadata.LENS_FACING_FRONT;
                break;
        }

        for (String cameraId : cameraIds) {
            CameraCharacteristics characteristics = null;
            try {
                characteristics = mCameraManager.getCameraCharacteristics(cameraId);
            } catch (CameraAccessException e) {
                throw new CameraInfoUnavailableException(
                        "Unable to retrieve info for camera with id " + cameraId + ".", e);
            }
            Integer cameraLensFacing = characteristics.get(CameraCharacteristics.LENS_FACING);
            if (cameraLensFacing == null) {
                continue;
            }
            if (cameraLensFacing.equals(lensFacingInteger)) {
                return cameraId;
            }
        }

        return null;
    }

It boils down to picking the first camera that matches the orientation from the camera service. I would assume that they will expand those apis in the future camerax release.

user_2718770
Related