Presentation - Screen share
Presentation means sharing a screen of a user (presenter) to show a material such as slides to the other call peers. This page describes how to use the presentation function based on the call type.
| Supported call type | Minimum SDK version |
|---|---|
| 1-to-1 call, group call (conference) | PlanetKit 3.0 |
PlanetKit uses HD resolution in its presentation feature, so it can provide an optimized service when the client's network conditions meet or exceed the recommended bandwidth.
1-to-1 call presentation
To start or end a presentation in a 1-to-1 call, use startMyScreenShare() or stopMyScreenShare() of PlanetKitCall.
Related APIs
The following table shows APIs related to screen share in a 1-to-1 call, where a counterpart means a peer to whom to show the presentation.
| Presenter-side API | Description | Counterpart-side API | Description |
|---|---|---|---|
startMyScreenShare() iOS, macOS | Starts screen share by a presenter | peerDidStartScreenShare iOS, macOS | Screen share by a presenter has been started |
| - | - | addPeerScreenShareView() iOS, macOS | Sets a view instance created by an application |
stopMyScreenShare() iOS, macOS | Ends screen share by the presenter | peerDidStopScreenShare iOS, macOS | Screen share by the presenter has been stopped |
| - | - | removePeerScreenShareView() iOS, macOS | Removes the view instance before release |
After being notified by peerDidStartScreenShare that a presentation has started, the counterpart side must create a view instance and call addPeerScreenShareView() to let PlanetKit render the shared screen.
The presentation video data is automatically streamed to the peer.
1-to-1 call presentation flow
The following diagram shows the flow for starting a presentation in 1-to-1 calls.
The following diagram shows the flow for stopping a presentation in 1-to-1 calls.
Reason to stop screen share
When you call stopMyScreenShare(), you can add one of the reasons defined as application requirements. In that case, the event peerDidStopScreenShare delivers the value of the reason to the counterparts. This value is an integer type, so you must define the reasons and their values and use them consistently across applications of different platforms.
If the reason field is not used, the hasReason field of peerDidStopScreenShare is set to false.
Group call presentation
To start or end a presentation in a group call, use startMyScreenShare() or stopMyScreenShare() of PlanetKitConference.
Related APIs
The following table shows APIs related to screen share in a group call, where counterparts mean participants in a group call to whom to show the presentation.
| Presenter-side API | Description | Counterpart-side API | Description |
|---|---|---|---|
startMyScreenShare() iOS, macOS | Starts screen share by a presenter | screenShareDidUpdate iOS, macOS(state=ENABLED) | Screen share by a presenter has been started |
| - | - | startScreenShare() of PlanetKitPeerControl iOS, macOS | Starts rendering the screen share video on a screen share view |
stopMyScreenShare() iOS, macOS | Ends screen share by the presenter | screenShareDidUpdate iOS, macOS(state=DISABLED) | Screen share by the presenter has been stopped |
| - | - | stopScreenShare() of PlanetKitPeerControl iOS, macOS | Stops rendering the screen share video on a screen share view |
changeMyScreenShareDestination() iOS, macOSchangeMyScreenShareDestinationToMainRoom() iOS, macOS | Changes the destination subgroup of the screen share. | screenShareDidUpdate iOS, macOS(state=ENABLED) screenShareDidUpdate iOS, macOS(state=DISABLED) | Screen share to a specific subgroup has been started or stopped |
You can use the methods of PlanetKitPeerControl to control screen share video on a peer's screen share view. For more information on how to use PlanetKitPeerControl, refer to the group call screen share code example.
After being notified by screenShareDidUpdate of PlanetKitConferenceDelegate or didUpdateScreenShare of PlanetKitPeerControlDelegate that a presentation has started (state=ENABLED), the counterpart side must call startScreenShare() of PlanetKitPeerControl to let PlanetKit render the shared screen.
Unlike 1-to-1 calls, presentation video data is not automatically streamed to participants. Therefore, the counterpart side in group calls must call startScreenShare() of PlanetKitPeerControl to receive the presentation video data.
Group call presentation flow
The following diagram shows the flow for starting a presentation in group calls.
The following diagram shows the flow for stopping a presentation in group calls.
The following diagram shows the flow for a user who joined after a presentation started in a group call.
Presentation within a subgroup
A presentation feature is available within a subgroup when the presenter subscribed to the subgroup with the "dataSession" attribute set to true. If the presenter starts a presentation within a subgroup scope, the presentation video data is only shared with the members of the subgroup.
To change the destination subgroup of the screen share, use changeMyScreenShareDestination() or changeMyScreenShareDestinationToMainRoom(). For more information, see Subgroup flow - Screen share.
Starting from PlanetKit 4.1, the function to receive two screen share streams at the same time is supported. Receiving two presentation videos might cause confusing UX or heavy traffic. However, it can be useful in relation to the subgroup feature.
For example, let's say the first presenter started a presentation to all participants, and the second presenter started a presentation within a subgroup scope. Subgroup members can choose to receive one of them or both by controlling startScreenShare() of PlanetKitPeerControl.
Group call compatibility
Since PlanetKit 4.1, presentation video is not automatically sent to participants. Accordingly, PlanetKit 4.1 added screenShareDidUpdate and requestPeerScreenShare(), and started to support a presentation feature within a subgroup scope.
This does not affect the behavior of WebPlanetKit and older versions of PlanetKit, which do not support the subgroup feature. That is, LINE Planet Cloud automatically streams presentation video data to clients using WebPlanetKit or older versions of PlanetKit.
Desktop considerations
A desktop application allows the presenter to select either the full screen of the monitor or a window of an application. Therefore, applications on Windows and macOS must determine which screen to share before calling startMyScreenShare(). PlanetKit provides a list of available screens for your application. For details, refer to the sample code.
To handle the view change by a presenter, such as running a slideshow, you must call the following method:
| OS | Related API |
|---|---|
| macOS | change(device:completion:) of PlanetKitScreen |
| Windows | ScreenShareController::StartScreenShareCapture() |