Introduction

During a video call or live broadcast, sharing the screen enhances communication by displaying the speaker's screen on the display of other speakers or audience members in the channel.

Screen sharing is applied in the following scenarios:

  • In a video conference, the speaker can share an image of a local file, web page, or presentation with other users in the channel.
  • In an online class, the teacher can share the slides or notes with students.

Implementation

Before proceeding, ensure that you implement a basic call or live broadcast in your project. See Start a Call or Start a Live Broadcast for details.

The Agora SDK does not provide specific methods for screen sharing on Android. With system methods provided by Android, you can enable screen sharing with the following steps:

  • Use MediaProjection/VirtualDisplay to get the screen image data.
  • Maintain an OpenGL environment, create a SurfaceView and pass the View to VirtualDisplay as the recipient of the screen image data.
  • Take the image data retrieved from the SurfaceView callback as the external video source. Call the pushExternalVideoFrame method to transfer the image data to the remote user.
MediaProjectionManager projectManager = (MediaProjectionManager) mContext.getSystemService(
Context.MEDIA_PROJECTION_SERVICE);

// Create the intent for screen capture. Call the startActivityForResult method to use the sharing function.
Intent intent = projectManager.createScreenCaptureIntent();
startActivityForResult(intent);

MediaProjection projection;
VirtualDisplay display;

// Override and implement the onActivityResult method of the Activity where you just called startActivityForResult.
@Override
onActivityResult(int requestCode, int resultCode, Intent resuleData) {
    projection = projectManager.getMediaProjection(resultCode, resultData);
    display = projection.createVirtualDisplay(name, width, height, dpi, flags, surface, callback, handler);
}

// The texture retrieved from the Surface will be sent by the SDK.
rtcEngine.pushExternalVideoFrame(new AgoraVideoFrame(...));

// Stop screen sharing.
projection.stop();

We also provide an open-souce Switch External Video demo project on GitHub. You can go to the repository to download it. You can try the demo and refer to the source code of the startScreenShare method in the switchVideoInputActivity.java file.

Considerations