private void Start()
{
//BufferChunk chunk = new BufferChunk(2048);
CompoundPacket compoundPacket = new CompoundPacket();
EndPoint endPoint = null;
while (isRunning)
{
try
{
compoundPacket.Reset();
udpListener.ReceiveFrom(compoundPacket.Buffer, out endPoint);
compoundPacket.ParseBuffer();
//IPAddress ipAddress = ((IPEndPoint)endPoint).Address;
IPEndPoint ipEndpoint = (IPEndPoint)endPoint;
// The compound packet enumerator destroys its list during enumeration,
// so we keep track of packets that have yet to be processed
IList<RtcpPacket> yetToBeProcessed = new List<RtcpPacket>();
String venueName = null;
//uint ssrc = 0;
long when = 0; // in units of "ticks"
// scan through the compound packet, looking for key pieces of meta-data
// first, look for the app packet that specifies the venue
// also, obtain the ssrc and the time stamp
foreach (RtcpPacket packet in compoundPacket)
{
if (packet.PacketType == (byte)Rtcp.PacketType.APP)
{
AppPacket appPacket = new AppPacket(packet);
if (appPacket.Name.Equals(Rtcp.APP_PACKET_NAME) &&
appPacket.Subtype == Rtcp.VENUE_APP_PACKET_SUBTYPE)
{
BufferChunk chunk = new BufferChunk(appPacket.Data);
when = chunk.NextInt64();
venueName = chunk.NextUtf8String(chunk.Length);
int padIndex = venueName.IndexOf((char)0);
if (padIndex > 0)
venueName = venueName.Substring(0, padIndex);
}
}
else
{
yetToBeProcessed.Add(packet);
}
}
if (venueName == null)
continue; // can't do anything if we don't know the venue for this packet
if (when == 0)
continue; // need a timestamp
VenueState venueState = null;
// compound operations must always be locked...
lock (venueStateMap)
{
if (!venueStateMap.ContainsKey(venueName))
venueState = new VenueState(venueName);
else venueState = venueStateMap[venueName];
}
// scan again, this time processing the RTCP packets
foreach (RtcpPacket packet in yetToBeProcessed)
{
switch (packet.PacketType)
{
case (byte)Rtcp.PacketType.SR:
{
SrPacket sr = new SrPacket(packet);
SenderData senderData = venueState.GetSenderState(sr.SSRC);
senderData.Source = ipEndpoint;
senderData.updateSenderState(sr.SenderReport, when);
// this "refreshes" the host state (so that it won't expire)
venueState.SenderData[sr.SSRC] = senderData;
break;
}
case (byte)Rtcp.PacketType.RR:
{
RrPacket rr = new RrPacket(packet);
ReceiverData receiverData = venueState.GetReceiverData (ipEndpoint);
// currently, we replace all receiver summaries with the data
// from a single RR packet
receiverData.updateReceiverState(rr.ReceiverReports, when, venueState);
// this "refreshes" the host state (so that it won't expire)
venueState.ReceiverData[ipEndpoint] = receiverData;
break;
}
case (byte)Rtcp.PacketType.SDES:
{
SdesPacket sdp = new SdesPacket(packet);
foreach(SdesReport report in sdp.Reports())
{
SenderData senderData = venueState.GetSenderState(report.SSRC);
senderData.CName = report.SdesData.CName;
senderData.Source = ipEndpoint;
// this "refreshes" the host state (so that it won't expire)
venueState.SenderData[report.SSRC] = senderData;
ReceiverData receiverData =
venueState.GetReceiverDataWithoutCreating(ipEndpoint);
if (receiverData != null)
receiverData.CName = report.SdesData.CName;
}
break;
}
case (byte)Rtcp.PacketType.BYE:
{
//BYE packets occur when capabilities stop. Clean out sender data only for the
//ssrc's affected. We leave receiver reports alone for now.
ByePacket byePacket = new ByePacket(packet);
foreach (uint ssrc in byePacket.SSRCs) {
venueState.SenderData.Remove(ssrc);
}
//Set a flag to cause the matrix for this venue to be rebuilt on the next request.
venueState.ParticipantChange = true;
continue;
}
case (byte)Rtcp.PacketType.APP:
{
// ignored
break;
}
}
} // foreach packet...
// refresh the venue state
venueStateMap[venueName] = venueState;
}
catch (Exception e)
{
Console.Out.WriteLine("Exception : " + e.ToString());
writeEventLog("Exception in receive thread: " + e.ToString(), EventLogEntryType.Warning);
}
} // loop forever...
}