渲染现有参与者的视频轨道

Question

So I connect to a room, which might already have existing participants sharing their videos. However when I try to iterate through all the participants and add their respective videos...it doesn't work. For some reason, even though the participant count is not 0. How do I get the video tracks of all the existing participants in a room and render them?

So basically this is the workflow:

1. User 1 and 2 enters room and shares their videos
2. User 3 enters room, and wants to show the video of the existing participants on screen(eg user 1 and 2 who logged in before him) How do I do that? )

Here is my code for the didConnect() delegate which fires when one enters a room.the addVideoTrack function renders the video for any new participants, so its working fine, but I want to do it for previously existing participants.

    func didConnect(to room: TVIRoom) {
    connectedParticipants = room.participants
    for participant in connectedParticipants {

        for videoTrack in participant.videoTracks {
            addVideoTrack(videoTrack:videoTrack)
        }

    }

    changeRoomLabel(messageText: "Room: \(room.name)")
}

Answer 1

Twilio developer evangelist here.

When you connect to the room and find the participants, you may not have connected to their media streams yet. Instead, you should implement the TVIParticipantDelegate . As you can see in the Twilio Video quickstart application (which only handles one external participant, but is a good example), when connecting to a room set the controller as the participant's delegate:

func didConnect(to room: TVIRoom) {
    if (room.participants.count > 0) {
        self.participant = room.participants[0]
        self.participant?.delegate = self
    }
}

Then, the example implements the TVIParticipantDelegate participant:addedVideoTrack to render the video once it is added to the participant:

extension ViewController : TVIParticipantDelegate {
    func participant(_ participant: TVIParticipant, addedVideoTrack videoTrack: TVIVideoTrack) {
        logMessage(messageText: "Participant \(participant.identity) added video track")

        if (self.participant == participant) {
            setupRemoteVideoView()
            videoTrack.addRenderer(self.remoteView!)
        }
    }
}

And the other delegate methods here .

Let me know if that helps at all.