如何在视频/音频通话中远程共享屏幕？

Question

我正在尝试构建一个具有屏幕共享功能的视频通话应用程序。用户可以在通话期间共享屏幕。我正在使用WebRTC SDK来满足我的目的，但他们在呼叫开始时有屏幕共享的解决方案，但在呼叫正在进行时没有屏幕共享。可以勾选屏幕共享选项并可以启动呼叫，但无法在通话期间启动屏幕共享。

我在CallActivity屏幕上添加了一个按钮，在点击时调用MediaProjection Class of android来投射屏幕，但是没有远程显示投射屏幕。

public void onScreenShare(boolean isScreenShared) {
    screencaptureEnabled = isScreenShared;
    if (screencaptureEnabled && videoWidth == 0 && videoHeight == 0) {
        DisplayMetrics displayMetrics = getDisplayMetrics();
        videoWidth = displayMetrics.widthPixels;
        videoHeight = displayMetrics.heightPixels;
    }

    if (isPemitted()) {
        startScreenCapture();
    } else {
        Log.i(TAG, "onScreenShare: not permitted");
    }

    /*if (peerConnectionClient != null) {
        peerConnectionClient.stopVideoSource();
    }*/
}

private void startScreenCapture() {
    MediaProjectionManager mediaProjectionManager =
            (MediaProjectionManager) getApplication().getSystemService(
                    Context.MEDIA_PROJECTION_SERVICE);
    startActivityForResult(
            mediaProjectionManager.createScreenCaptureIntent(), 
CAPTURE_PERMISSION_REQUEST_CODE);
    Log.d("tagged", ">>>>Method called :- ");
}

@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) 
{
    Log.d("tagged", ">>>>Method called :- " + requestCode);
    if (requestCode != CAPTURE_PERMISSION_REQUEST_CODE)
        return;
    else {
        mediaProjectionPermissionResultCode = resultCode;
        mediaProjectionPermissionResultData = data;

if (peerConnectionParameters.videoCallEnabled) {
        videoCapturer = createVideoCapturer();
    }
    peerConnectionClient.createPeerConnection(
            localProxyVideoSink, remoteSinks, videoCapturer, 
 signalingParameters);
    }
}

private @Nullable
VideoCapturer createScreenCapturer() {
    Log.d("CheckMedia", ">>>Checking " + 
mediaProjectionPermissionResultData);
    if (mediaProjectionPermissionResultCode != Activity.RESULT_OK) {
        reportError("User didn't give permission to capture the screen.");
        return null;
    }
    return new ScreenCapturerAndroid(
            mediaProjectionPermissionResultData, new 
MediaProjection.Callback() {
        @Override
        public void onStop() {
            reportError("User revoked permission to capture the screen.");
        }
    });
}

此代码在本地设备上启动转换，但不在远程设备上传输任何内容。

UPDATE

 private void switchCameraInternal() {
    if (videoCapturer instanceof CameraVideoCapturer) {
        if (!isVideoCallEnabled() || isError) {
            Log.e(TAG,
                    "Failed to switch camera. Video: " + 
 isVideoCallEnabled() + ". Error : " + isError);
            return; // No video is sent or only one camera is available or 
 error happened.
        }
        Log.d(TAG, "Switch camera");
        CameraVideoCapturer cameraVideoCapturer = (CameraVideoCapturer) 
 videoCapturer;
        cameraVideoCapturer.switchCamera(null);

    } else {
        Log.d(TAG, "Will not switch camera, video caputurer is not a 
camera");
    }
 }

public void switchCamera() {
    executor.execute(this::switchCameraInternal);
}

private void startScreenSharing() {
    if (videoCapturer instanceof ScreenCapturerAndroid) {
        if (!isVideoCallEnabled() || isError) {
            Log.e(TAG,
                    "Failed to share screen. Video: " + isVideoCallEnabled() 
+ ". Error : " + isError);
            return; // No video is sent or only one camera is available or 
error happened.
        }
        ScreenCapturerAndroid screenCapturerAndroid = 
(ScreenCapturerAndroid) videoCapturer;
        screenCapturerAndroid.startCapture(500, 500, 30);
    }
}

public void screenSharing() {
    executor.execute(this::startScreenSharing);
}

我做了更改，并使代码看起来类似于switchCamera（）代码，但我得到一个Not On Camera Thread Exception。