iOS MCU Client Swift¶

Example of client for MCU conference participant¶

This example can be used to arrange an MCU video conference on Web Call Server. Each participant of such conference can publish a WebRTC stream and play a mixer stream with audio and video from the other participants and its own video (without its own audio).

The following settings are required in WCS flashphoner.properties

mixer_auto_start=true
mixer_mcu_audio=true
mixer_mcu_video=true

When a participant joins a conference using the client

a stream with video of the participant, named participantName + "\#" + roomName, is published
the participant's stream is added to mixer named roomName (in case such mixer did not exist, it is auto created)
a new mixer output stream named roomName + "-" + participantName + roomName and containing video from all the participants (including this one) and audio only from the other participants is created and played for the participant

On the screenshot below the participant is publishing a stream and playing his conference mixer stream:

Analyzing the example code¶

To analyze the code take MCUClientSwift class which is available on GitHub.

Main application view class: MCUViewController (implementation file MCUViewController.swift).

1. API import¶

code

import FPWCSApi2Swift

2. Session creation and connecting to the server¶

WCSSession, WCSSession.connect code

The following session parameters are set:

WCS server URL
server REST hook application name defaultApp

@IBAction func joinPressed(_ sender: Any) {
    self.changeViewState(joinButton, false)
    if (joinButton.title(for: .normal) == "JOIN") {
        if (session == nil) {
            let options = FPWCSApi2SessionOptions()
            options.urlServer = serverField.text
            options.appKey = "defaultApp"
            do {
                try session = WCSSession(options)
            } catch {
                print(error)
            }
        }
        ...
        self.changeViewState(serverField, false)
        session?.connect()
    } else {
        leave()
    }

}

3. Participant stream publishing¶

WCSSession.createStream, WCSStream.publish code

The following parameters are passed to createStream method:

stream name to publish
local view to display
WebRTC transport type
audio and video publishing constraints

func publish() {
    ...
    let constraints = FPWCSApi2MediaConstraints()
    if (audioSwitch.isOn) {
        constraints.audio = FPWCSApi2AudioConstraints()
    }
    if (videoSwitch.isOn) {
        constraints.video = FPWCSApi2VideoConstraints()
    }
    let options = FPWCSApi2StreamOptions()
    options.name = loginField.text! + "#" + roomField.text!
    options.transport = transportSwitch.isOn ? kFPWCSTransport.fpwcsTransportTCP : kFPWCSTransport.fpwcsTransportUDP
    options.constraints = constraints
    options.display = localDisplay.videoView
    do {
        publishStream = try session!.createStream(options)
    } catch {
        print(error);
    }
    ...        
    do {
        try publishStream?.publish()
    } catch {
        print(error);
    }
}

4. MCU mixer stream playback¶

WCSSession.createStream, WCSStream.play code

The following parameters are passed to createStream method:

stream name to play
remote view to display
WebRTC transport type

func play() {
    ...
    let options = FPWCSApi2StreamOptions()
    options.name = roomField.text! + "-" + loginField.text! + roomField.text!
    options.transport = transportSwitch.isOn ? kFPWCSTransport.fpwcsTransportTCP : kFPWCSTransport.fpwcsTransportUDP
    options.display = remoteDisplay.videoView;
    do {
        playStream = try session!.createStream(options)
    } catch {
        print(error)
    }
    ...
    do {
        try playStream?.play()
    } catch {
        print(error);
    }
}

5. Stream playback stopping¶

WCSStream.stop code

func stopPlay() {
    do {
        try playStream?.stop();
    } catch {
        print(error);
    }
    playStream = nil;
}

6. Stream publishing stopping¶

WCSStream.stop code

func stopPublish() {
    do {
        try publishStream?.stop()
    } catch {
        print(error);
    }
    publishStream = nil;
}

7. Connection closing¶

WCSSession.disconnect code

func leave() {
    session?.disconnect()
    session = nil;
}