ConferenceService

The ConferenceService allows the application to manage the conference life-cycle and interact with the conference.

Typical API workflow:

1. The application calls the create method to create a conference.

2. The application calls the fetch method to receive the conference object.

3. The application joins the conference through the join or listen method.

4. The application can interact with the conference to:

• Request a specific quality of received Simulcast video streams through the Simulcast method.

• Send audio streams using the startAudio and stopAudio methods.

• Customize the number of the received video streams and prioritize the selected participants' video streams.

• Send media and video streams using the startVideo and stopVideo methods.

• Share the screen using the startScreenShare and stopScreenShare methods.

• Replay the recorded conference through the replay method.

• Check the audio level using the audioLevel method.

• Check the speaking status of a participant using the isSpeaking method.

• Control the mute input state of conference participants through the mute method.

• Inform whether a local participant is muted.

• Control the mute output state of conference participants through the muteOutput method.

• Check WebRTC statistics through the localStats method.

• Control the audio processing state through the audioProcessing method.

• Update a participant's permissions through the updatePermissions method.

• Kick a participant from the conference when the conference access token is updated using the kick method.

5. The application calls the leave method to leave the conference.

Events are emitted in the following situations:

• A new participant joined the conference and changed status.
• A stream was added, updated, or removed.
• The conference changed its status.
• A participant's permissions are updated.

Events

participantAdded

▸ participantAdded(participant: VTParticipant)

Emitted when a new participant is invited to a conference. The SDK does not emit the participantAdded event for the local participant. Listeners only receive the participantAdded events about users; they do not receive events for other listeners. In SDK 3.2 and prior releases, users receive events about users and the first 1000 listeners. However, in SDK 3.3 and next releases, users receive the participantAdded events about users and do not receive any events about listeners. To notify all application users about the number of participants who are present at a conference, the iOS SDK 3.3 introduces the activeParticipants events.

Parameters:

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participantUpdated

▸ participantUpdated(participant: VTParticipant)

Emitted when a participant changes status. Listeners only receive the participantUpdated events about users; they do not receive events for other listeners. In SDK 3.2 and prior releases, users receive events about users and the first 1000 listeners. However, in SDK 3.3 and next releases, users receive the participantUpdated events about users and do not receive any events about listeners. To notify all application users about the number of participants who are present at a conference, the iOS SDK 3.3 introduces the activeParticipants events.

The following graphic shows possible status changes during a conference:

Parameters:

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permissionsUpdated

▸ permissionsUpdated(permissions: [Int])

Emitted when the local participant's permissions are updated.

Parameters:

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statusUpdated

▸ statusUpdated(status: VTConferenceStatus)

Emitted when the conference status is updated.

Parameters:

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streamAdded

▸ streamAdded(participant: VTParticipant, stream: MediaStream)

Emitted when the SDK adds a new stream to a conference participant. Each conference participant can be connected to two streams: the audio and video stream and the screen-share stream. If a participant enables audio or video, the SDK adds the audio and video stream to the participant and emits the streamAdded event to all participants. When a participant is connected to the audio and video stream and changes the stream, for example, enables a camera while using a microphone, the SDK updates the audio and video stream and emits the streamUpdated event. When a participant starts sharing a screen, the SDK adds the screen-share stream to this participants and emits the streamAdded event to all participants. The following graphic shows this behavior:

When a new participant joins a conference with enabled audio and video, the SDK emits the streamAdded event that includes audio and video tracks.

The SDK can also emit the streamAdded event only for the local participant. When the local participant uses the stopAudio method to locally mute the selected remote participant who does not use a camera, the local participant receives the streamRemoved event. After using the startAudio method for this remote participant, the local participant receives the streamAdded event.

Parameters:

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streamUpdated

▸ streamUpdated(participant: VTParticipant, stream: MediaStream)

Emitted when a conference participant who is connected to the audio and video stream changes the stream by enabling a microphone while using a camera or by enabling a camera while using a microphone. The event is emitted to all conference participants. The following graphic shows this behavior:

The SDK can also emit the streamUpdated event only for the local participant. When the local participant uses the stopAudio or startAudio method to locally mute or unmute a selected remote participant who uses a camera, the local participant receives the streamUpdated event.

Parameters:

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streamRemoved

▸ streamRemoved(participant: VTParticipant, stream: MediaStream)

Emitted when the SDK removes a stream from a conference participant. Each conference participant can be connected to two streams: the audio and video stream and the screen-share stream. If a participant disables audio and video or stops a screen-share presentation, the SDK removes the proper stream and emits the streamRemoved event to all conference participants.

The SDK can also emit the streamRemoved event only for the local participant. When the local participant uses the stopAudio method to locally mute a selected remote participant who does not use a camera, the local participant receives the streamRemoved event.

Parameters:

Accessors

current

▸ current: VTConference?

Returns information about the current conference. Use this accessor if you wish to receive information that is available in the VTConference object, such as the conference alias, ID, information if the conference is new, the list of the conference participants, conference parameters, local participant's conference permissions, or conference status.

Returns: VTConference?

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cryptoDelegate

▸ cryptoDelegate: VTConferenceCryptoDelegate

The encrypted delegate, a means of communication between objects in the conference service.

Note: This API is no longer supported in iOS Client SDK 3.0.0.

Returns: VTConferenceCryptoDelegate

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delegate

▸ delegate: VTConferenceDelegate

Delegate, a means of communication between objects in the conference service.

Returns: VTConferenceDelegate

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maxVideoForwarding

▸ maxVideoForwarding: Int

Provides the maximum number of video streams that may be transmitted to the local participant.

Returns: Int

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Methods

audioLevel

▸ audioLevel(participant: VTParticipant): Double

Gets the participant's audio level. The audio level value ranges from 0.0 to 1.0.

Note: When the local participant is muted, the audioLevel value is set to a non-zero value, and isSpeaking is set to true if the audioLevel is greater than 0.05. This implementation allows adding a warning message to notify the local participant that their audio is not sent to a conference.

Parameters:

Returns: Double

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audioProcessing

▸ audioProcessing(enable: boolean)

Enables and disables audio processing.

Parameters:

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create

▸ create(options: VTConferenceOptions?, success: (( conference: VTConference) -> Void)?, fail: (( error: NSError) -> Void)?)

Creates a conference.

Parameters:

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fetch

▸ fetch(conferenceID: String, completion: (VTConference) -> Void)

Provides the conference object that allows joining a conference. For more information about using the fetch method, see the Conferencing document.

Parameters:

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isSpeaking

▸ isSpeaking(participant: VTParticipant) : Bool

Gets the participant's current speaking status.

Parameters:

Returns: Bool

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isMuted

▸ isMuted() -> Bool

Informs whether a participant is muted.

Note: This API is no longer supported for remote participants.

Returns: Bool

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join

▸ join(conference: VTConference, options: VTJoinOptions?, success: (( conference: VTConference) -> Void)?, fail: (( error: NSError) -> Void)?)

Joins a conference. For more information about joining conferences, see the Conferencing document.

Parameters:

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kick

▸ kick(participant: VTParticipant, completion: ((_ error: NSError) -> Void)?)

Allows the conference owner, or a participant with adequate permissions, to kick another participant from the conference by revoking the conference access token. The kicked participant cannot join the conference again.

Parameters:

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leave

▸ leave(completion: ((_ error: NSError?) -> Void)?)

Leaves the conference.

Parameters:

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listen

▸ listen(conference: VTConference, options: VTListenOptions?, success: (( conference: VTConference) -> Void)?, fail: (( error: NSError) -> Void)?)

Joins a conference as a listener.

Note: Conference events from other listeners are not available for listeners. Only users will receive conference events from other listeners.

Parameters:

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localStats

▸ localStats(): [[String: Any]]?

Provides the WebRTC statistics.

Returns: [[String: Any]]?

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mute

▸ mute(participant: VTParticipant, isMuted: boolean, completion: ((_ error: NSError?) -> Void)? = nil

Stops playing the specified remote participants' audio to the local participant or stops playing the local participant's audio to the conference. The mute method does not notify the server to stop audio stream transmission. To stop sending an audio stream to the server or to stop receiving an audio stream from the server, use the stopAudio method.

Note: The mute method depends on the Dolby Voice usage:

• In conferences where Dolby Voice is not enabled, conference participants can mute themselves or remote participants.
• In conferences where Dolby Voice is enabled, conference participants can only mute themselves.

If you wish to mute remote participants in Dolby Voice conferences, we recommend using the stopAudio API. This API allows the conference participants to stop receiving the specific audio streams from the server.

Parameters:

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muteOutput

▸ muteOutput(isMuted: boolean, completion: ((_ error: NSError?) -> Void)?)

Controls playing remote participants' audio to the local participant.

Note: This API is only supported when the client connects to a Dolby Voice conference.

Parameters:

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replay

▸ replay(conference: VTConference, options: VTReplayOptions?, completion: ((_ error: NSError?) -> Void)?)

Replays the recorded conference.

Parameters:

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startAudio

▸ startAudio(participant: VTParticipant?, completion: ((_ error: NSError?) -> Void)?)

Starts audio transmission between the local client and a conference. The startAudio method impacts only the audio streams that the local participant sends and receives; the method does not impact the audio transmission between remote participants and a conference and does not allow the local participant to force sending remote participants’ streams to the conference or to the local participant. Depending on the specified participant in the participant parameter, the startAudio method starts the proper audio transmission:

• When the specified participant is the local participant, startAudio ensures sending local participant’s audio from the local client to the conference.

• When the specified participant is a remote participant, startAudio ensures sending remote participant’s audio from the conference to the local client. This allows the local participant to unmute remote participants who are locally muted through the stopAudio method.

The startAudio method in Dolby Voice conferences is not available for listeners.

The startAudio method requires up to a few seconds to become effective.

Parameters:

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startScreenShare

▸ startScreenShare(broadcast: boolean, completion: ((_ error: NSError?) -> Void)?)

Starts a screen-sharing session. The ScreenShare with iOS document describes how to set up screen-share outside the application.

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startVideo

▸ startVideo(participant: VTParticipant?, isDefaultFrontFacing: Bool, completion: ((_ error: NSError?) -> Void)?)

Notifies the server to either start sending the local participant's video stream to the conference or start sending a remote participant's video stream to the local participant. The startVideo method does not control the remote participant's video stream; if a remote participant does not transmit any video stream, the local participant cannot change it using the startVideo method.

Parameters:

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simulcast

▸ simulcast(requested: [VTParticipantQuality], completion: ((_ error: NSError?) -> Void)?)

Requests a specific quality of the received Simulcast video streams. You can use this method for selected conference participants or for all participants who joined the conference.

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stopAudio

▸ stopAudio(participant: VTParticipant?, completion: ((_ error: NSError?) -> Void)?)

Stops audio transmission between the local client and a conference. The stopAudio method impacts only the audio streams that the local participant sends and receives; the method does not impact the audio transmission between remote participants and a conference and does not allow the local participant to stop sending remote participants’ streams to the conference. Depending on the specified participant in the participant parameter, the stopAudio method stops the proper audio transmission:

• When the specified participant is the local participant, stopAudio stops sending local participant’s audio from the local client to the conference.

• When the specified participant is a remote participant, stopAudio stops sending remote participant’s audio from the conference to the local client. This allows the local participant to locally mute remote participants.

The stopAudio method in Dolby Voice conferences is not available for listeners.

Leaving a conference resets the stopAudio settings. Participants who rejoin a conference need to provide the desired stopAudio parameters and call the stopAudio method once again.

The stopAudio method requires up to a few seconds to become effective.

Parameters:

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stopScreenShare

▸ stopScreenShare(completion: ((_ error: NSError?) -> Void)?)

Stops a screen-sharing session.

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stopVideo

▸ stopVideo(participant: VTParticipant?, completion: ((_ error: NSError?) -> Void)?)

Notifies the server to either stop sending the local participant's video stream to the conference or stop sending a remote participant's video stream to the local participant.

Parameters:

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updatePermissions

▸ updatePermissions(participantPermissions: VTParticipantPemissions, completion: ((_ error: NSError) -> Void)?)

Updates the participant's conference permissions. If a participant does not have permission to perform a specific action, this action is not available for this participant during a conference. If a participant started a specific action and then lost permission to perform this action, the SDK stops the blocked action. For example, if a participant started sharing a screen and received the updated permissions that do not allow him to share a screen, the SDK stops the screen sharing session and the participant cannot start sharing the screen again.

Parameters:

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videoForwarding

▸ videoForwarding(max: Int, participants: [VTParticipant]?, completion: ((_ error: NSError?) -> Void)?)

Sets the maximum number of video streams that may be transmitted to the local participant. This method also allows the local participant to use a pin option to prioritize the specific participant's video streams and display their videos even when these participants do not talk. For more information, see the Video Forwarding article.

Parameters: