Android screen sharing using WebRTC

Question

I have heard about screen sharing on desktop using WebRTC. But for the Android, it seems not to have much information.

My question is:

1. Is it possible to use WebRTC for screen sharing on android?. I mean I can cast the current screen to the other phone's screen.
2. If 1 is Yes, How can I achieve this?

Thanks.

Answer 1

1. It is possible!
2. It can be done using the directions below.

I've used ScreenShareRTC in conjunction with ProjectRTC to stream the contents of the screen to a browser with decent quality and fairly low latency ~100ms.

I've added an example below that shows how to configure a screen share as a video source and add it as a track on a stream.

Get the VideoCapturer

@TargetApi(21)
private VideoCapturer createScreenCapturer() {
    if (mMediaProjectionPermissionResultCode != Activity.RESULT_OK) {
        report("User didn't give permission to capture the screen.");
        return null;
    }
    return new ScreenCapturerAndroid(
            mMediaProjectionPermissionResultData, new MediaProjection.Callback() {
        @Override
        public void onStop() {
            report("User revoked permission to capture the screen.");
        }
    });
}

Initialize the capturer and add the tracks to the local media stream

private void initScreenCapturStream() {
    mLocalMediaStream = factory.createLocalMediaStream("ARDAMS");
    MediaConstraints videoConstraints = new MediaConstraints();
    videoConstraints.mandatory.add(new MediaConstraints.KeyValuePair("maxHeight", Integer.toString(mPeerConnParams.videoHeight)));
    videoConstraints.mandatory.add(new MediaConstraints.KeyValuePair("maxWidth", Integer.toString(mPeerConnParams.videoWidth)));
    videoConstraints.mandatory.add(new MediaConstraints.KeyValuePair("maxFrameRate", Integer.toString(mPeerConnParams.videoFps)));
    videoConstraints.mandatory.add(new MediaConstraints.KeyValuePair("minFrameRate", Integer.toString(mPeerConnParams.videoFps)));

    mVideoSource = factory.createVideoSource(videoCapturer);
    videoCapturer.startCapture(mPeerConnParams.videoWidth, mPeerConnParams.videoHeight, mPeerConnParams.videoFps);
    VideoTrack localVideoTrack = factory.createVideoTrack(VIDEO_TRACK_ID, mVideoSource);
    localVideoTrack.setEnabled(true);
    mLocalMediaStream.addTrack(factory.createVideoTrack("ARDAMSv0", mVideoSource));
    AudioSource audioSource = factory.createAudioSource(new MediaConstraints());
    mLocalMediaStream.addTrack(factory.createAudioTrack("ARDAMSa0", audioSource));

    mListener.onStatusChanged("STREAMING");
}

For more information this might be a good place to start. Its a Android project that connects to a ProjectRTC signalling server and shares the screen as video. I found it very helpful!

Android screen sharing project(Android client - Java) https://github.com/Jeffiano/ScreenShareRTC

ProjectRTC(Node server) https://github.com/pchab/ProjectRTC