/// <summary>
/// Adds the server media session.
/// </summary>
/// <param name="streamName">Name of the stream.</param>
/// <returns>The ServerMediaSession object.</returns>
private ServerMediaSession AddServerMediaSession(string streamName)
{
ServerMediaSession sms = null;
MPEG2TransportFileServerMediaSession mpeg2TransportFileSMS = new MPEG2TransportFileServerMediaSession(streamName);
if (mpeg2TransportFileSMS == null)
{
return(null); // Creates the MPEG2TransportFileServerMediaSubsession failed!
}
else
{
sms = mpeg2TransportFileSMS;
// Also, sets the file catalog:
mpeg2TransportFileSMS.FileCatalog = fileCatalog;
}
lock (serverMediaSessionTable)
{
serverMediaSessionTable.Add(streamName, sms);
}
return(sms);
}
/// <summary>
/// Handles the setup CMD.
/// </summary>
/// <param name="cseq">The cseq.</param>
/// <param name="urlPreSuffix">The URL pre suffix.</param>
/// <param name="urlSuffix">The URL suffix.</param>
/// <param name="request">The request string.</param>
private void HandleSetupCmd(string cseq, string urlPreSuffix, string urlSuffix, string request)
{
// Note: At present, I will use only one streaming mode of RTP_UDP
// to transfer the data between server and client.
// First, judges that the server media session exists or not.
if (serverMediaSession == null)
{
serverMediaSession = rtspServer.LookupServerMediaSession(urlPreSuffix);
if (serverMediaSession == null)
{
HandleNotFoundCmd(cseq);
return;
}
}
// Looks for a "Transport:" header in the request string,
// to extract client parameters:
int clientRtpPort;
int clientRtcpPort;
bool result = RtspCommon.ParseClientTransportHeader(request,
out clientRtpPort, out clientRtcpPort);
if (!result)
{
HandleUnsupportedTransportCmd(cseq);
return;
}
// Then, gets the server parameters from the server media session:
streamState = null;
string destinationAddr = base.ClientSessionIP;
string sourceAddr = Utils.GetLocalAddresses()[0];
int serverRtpPort = rtspServer.GenerateRtpPortNumber();
int serverRtcpPort = serverRtpPort + 1;
result = serverMediaSession.GetStreamParameters(base.ClientSessionId,
base.ClientSessionIP, clientRtpPort, clientRtcpPort,
serverRtpPort, serverRtcpPort, ref streamState);
if (!result)
{
HandleUnsupportedTransportCmd(cseq);
return;
}
// Generates the response information now.
StringBuilder sb = new StringBuilder();
sb.Append("RTSP/1.0 200 OK\r\n");
sb.AppendFormat("CSeq: {0}\r\n", cseq);
sb.AppendFormat("Date: {0}\r\n", DateTime.Now.ToLocalTime());
sb.Append("Transport: RTP/AVP;unicast;");
sb.AppendFormat("destination={0};source={1};", destinationAddr, sourceAddr);
sb.AppendFormat("client_port={0}-{1};", clientRtpPort, clientRtcpPort);
sb.AppendFormat("server_port={0}-{1}\r\n", serverRtpPort, serverRtcpPort);
sb.AppendFormat("Session: {0}\r\n\r\n", base.ClientSessionId);
response = sb.ToString();
}
/// <summary>
/// Lookups the server media session.
/// </summary>
/// <param name="streamName">Name of the stream.</param>
/// <returns>The ServerMediaSession object.</returns>
public ServerMediaSession LookupServerMediaSession(string streamName)
{
bool fileExists = false;
bool smsExists = false;
// First, checks whether the specified "streamName" exists as a local file.
string filePath = fileCatalog + streamName;
fileExists = File.Exists(filePath);
// Next, checks whether we already have a "ServerMediaSession" for this file.
ServerMediaSession sms = null;
lock (serverMediaSessionTable)
{
if (serverMediaSessionTable.ContainsKey(streamName))
{
sms = serverMediaSessionTable[streamName];
}
}
// The "ServerMediaSession" exists.
if (sms != null)
{
smsExists = true;
}
// Handles the four possibilities for "fileExists" and "smsExists".
if (!fileExists)
{
if (smsExists)
{
// "sms" was created for a file that no longer exists, so removes it.
RemoveServerMediaSession(streamName);
}
}
else
{
if (!smsExists)
{
// Creates a new "ServerMediaSession" object for streaming from the named file.
// And then add it to the table of ServerMediaSession.
sms = AddServerMediaSession(streamName);
}
}
return(sms);
}
/// <summary>
/// Handles the describe CMD.
/// </summary>
/// <param name="cseq">The cseq.</param>
/// <param name="rtspUrl">The rtsp url.</param>
/// <param name="urlSuffix">The URL suffix.</param>
/// <param name="request">The request string.</param>
private void HandleDescribeCmd(string cseq, string rtspUrl, string urlSuffix, string request)
{
base.StreamName = urlSuffix;
// Begins by looking up the "ServerMediaSession" object for the specified "urlSuffix":
serverMediaSession = rtspServer.LookupServerMediaSession(urlSuffix);
if (serverMediaSession == null)
{
HandleNotFoundCmd(cseq);
return;
}
// Then, assembles a SDP description for this session:
string sdpDescription = serverMediaSession.GenerateSdpDescription();
if (string.IsNullOrEmpty(sdpDescription))
{
HandleNotFoundCmd(cseq);
return;
}
int sdpDescriptionSize = sdpDescription.Length;
// Generates the response information now.
StringBuilder sb = new StringBuilder();
sb.Append("RTSP/1.0 200 OK\r\n");
sb.AppendFormat("CSeq: {0}\r\n", cseq);
sb.AppendFormat("Date: {0}\r\n", DateTime.Now.ToLocalTime());
sb.AppendFormat("Content-Base: {0}\r\n", rtspUrl);
sb.Append("Content-Type: application/sdp\r\n");
sb.AppendFormat("Content-Length: {0}\r\n\r\n", sdpDescriptionSize);
sb.AppendFormat("{0}", sdpDescription);
response = sb.ToString();
}
