private RosterParticipant GetParticipantWithDominantSpeakerMsi(uint dominantSpeakerMsi)
{
RosterParticipant firstParticipant = null;
if (_participants == null)
{
Log.Warning(new CallerInfo(), LogContext.FrontEnd, $"[{CallId}] Did not receive rosterupdate notification yet");
return(null);
}
string dominantSpeakerIdentity = string.Empty;
foreach (RosterParticipant participant in _participants)
{
if (participant.MediaStreamId == dominantSpeakerMsi.ToString())
{
//identify
if (participant.MediaType == ModalityType.Audio)
{
dominantSpeakerIdentity = participant.Identity;
continue;
}
}
if (participant.MediaType != ModalityType.Video ||
!(participant.MediaStreamDirection == "sendonly" || participant.MediaStreamDirection == "sendrecv")
)
{
continue;
}
//cache the first participant.. just incase dominant speaker is not sending video
if (firstParticipant == null)
{
firstParticipant = participant;
if (dominantSpeakerMsi == MediaSession.DominantSpeaker_None)
{
return(firstParticipant);
}
}
//The dominant speaker is sending video..
if (participant.Identity == dominantSpeakerIdentity)
{
return(participant);
}
}
//If dominant speaker is not sending video or if dominant speaker has exited the conference, choose the first participant sending video
return(firstParticipant);
}
/// <summary>
/// Subscribe to the video stream of a participant. This function is called when dominant speaker notification is received and when roster changes
/// When invoked on dominant speaker change, look if the participant is sharing their video. If yes then subscribe else choose the first participant in the list sharing their video
/// When invoked on roster change, verify if the previously subscribed-to participant is still in the roster and sending video
/// </summary>
/// <param name="msi">Msi of dominant speaker or previously subscribed to msi depending on where it is invoked</param>
/// <param name="msiOfDominantSpeaker">Gives more detail on the above msi.. Whether it is of dominant speaker or previously subscribed to video msi</param>
/// <returns></returns>
internal async Task Subscribe(uint msi, bool msiOfDominantSpeaker)
{
try
{
RosterParticipant participant;
Log.Info(new CallerInfo(), LogContext.FrontEnd, $"[{CallId}] Received subscribe request for Msi {msi} msiOfDominantSpeaker {msiOfDominantSpeaker}");
if (msiOfDominantSpeaker)
{
participant = GetParticipantWithDominantSpeakerMsi(msi);
}
else
{
participant = GetParticipantForRosterChange(msi);
}
if (participant == null)
{
_subscribedToParticipant = null;
return;
}
//if we have already subscribed earlier, skip the subscription
if (_subscribedToParticipant != null && _subscribedToParticipant.MediaStreamId == participant.MediaStreamId)
{
Log.Info(new CallerInfo(), LogContext.FrontEnd, $"[{CallId}] Already subscribed to {participant.Identity}. So skipping subscription");
return;
}
Log.Info(new CallerInfo(), LogContext.FrontEnd, $"[{CallId}] Subscribing to {participant.Identity} with msi {participant.MediaStreamId}");
//Get subscription details
var videoSubscription = new VideoSubscription
{
ParticipantIdentity = participant.Identity,
OperationId = Guid.NewGuid().ToString(),
SocketId = 0, //index of the VideoSocket in MediaConfiguration which receives the incoming video stream
VideoModality = ModalityType.Video,
VideoResolution = ResolutionFormat.Hd1080p
};
await CallService.Subscribe(videoSubscription).ConfigureAwait(false);
_subscribedToParticipant = participant;
}
catch (Exception ex)
{
Log.Error(new CallerInfo(), LogContext.FrontEnd, $"[{CallId}] Subscribe threw exception {ex.ToString()}");
_subscribedToParticipant = null;
}
}
private RosterParticipant GetParticipantForRosterChange(uint msi)
{
RosterParticipant firstParticipant = null;
if (_participants == null)
{
Log.Warning(new CallerInfo(), LogContext.FrontEnd, $"[{CallId}] Did not receive rosterupdate notification yet");
return(null);
}
string dominantSpeakerIdentity = string.Empty;
foreach (RosterParticipant participant in _participants)
{
if (participant.MediaStreamId == msi.ToString())
{
if (participant.MediaType == ModalityType.Video && (participant.MediaStreamDirection == "sendonly" || participant.MediaStreamDirection == "sendrecv"))
{
return(participant);
}
}
if (participant.MediaType != ModalityType.Video ||
!(participant.MediaStreamDirection == "sendonly" || participant.MediaStreamDirection == "sendrecv")
)
{
continue;
}
if (firstParticipant == null)
{
firstParticipant = participant;
}
}
//No dominant speaker or dominant speaker is not sending video or if old dominant speaker has exited the conference, choose a new oe
return(firstParticipant);
}