liveMedia/include/ServerMediaSession.hh

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00001 /**********
00002 This library is free software; you can redistribute it and/or modify it under
00003 the terms of the GNU Lesser General Public License as published by the
00004 Free Software Foundation; either version 2.1 of the License, or (at your
00005 option) any later version. (See <http://www.gnu.org/copyleft/lesser.html>.)
00006 
00007 This library is distributed in the hope that it will be useful, but WITHOUT
00008 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
00009 FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for
00010 more details.
00011 
00012 You should have received a copy of the GNU Lesser General Public License
00013 along with this library; if not, write to the Free Software Foundation, Inc.,
00014 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  USA
00015 **********/
00016 // "liveMedia"
00017 // Copyright (c) 1996-2012 Live Networks, Inc.  All rights reserved.
00018 // A data structure that represents a session that consists of
00019 // potentially multiple (audio and/or video) sub-sessions
00020 // (This data structure is used for media *streamers* - i.e., servers.
00021 //  For media receivers, use "MediaSession" instead.)
00022 // C++ header
00023 
00024 #ifndef _SERVER_MEDIA_SESSION_HH
00025 #define _SERVER_MEDIA_SESSION_HH
00026 
00027 #ifndef _MEDIA_HH
00028 #include "Media.hh"
00029 #endif
00030 #ifndef _FRAMED_SOURCE_HH
00031 #include "FramedSource.hh"
00032 #endif
00033 #ifndef _GROUPEID_HH
00034 #include "GroupEId.hh"
00035 #endif
00036 #ifndef _RTP_INTERFACE_HH
00037 #include "RTPInterface.hh" // for ServerRequestAlternativeByteHandler
00038 #endif
00039 
00040 class ServerMediaSubsession; // forward
00041 
00042 class ServerMediaSession: public Medium {
00043 public:
00044   static ServerMediaSession* createNew(UsageEnvironment& env,
00045                                        char const* streamName = NULL,
00046                                        char const* info = NULL,
00047                                        char const* description = NULL,
00048                                        Boolean isSSM = False,
00049                                        char const* miscSDPLines = NULL);
00050 
00051   virtual ~ServerMediaSession();
00052 
00053   static Boolean lookupByName(UsageEnvironment& env,
00054                               char const* mediumName,
00055                               ServerMediaSession*& resultSession);
00056 
00057   char* generateSDPDescription(); // based on the entire session
00058       // Note: The caller is responsible for freeing the returned string
00059 
00060   char const* streamName() const { return fStreamName; }
00061 
00062   Boolean addSubsession(ServerMediaSubsession* subsession);
00063   unsigned numSubsessions() const { return fSubsessionCounter; }
00064 
00065   void testScaleFactor(float& scale); // sets "scale" to the actual supported scale
00066   float duration() const;
00067     // a result == 0 means an unbounded session (the default)
00068     // a result < 0 means: subsession durations differ; the result is -(the largest)
00069     // a result > 0 means: this is the duration of a bounded session
00070 
00071   unsigned referenceCount() const { return fReferenceCount; }
00072   void incrementReferenceCount() { ++fReferenceCount; }
00073   void decrementReferenceCount() { if (fReferenceCount > 0) --fReferenceCount; }
00074   Boolean& deleteWhenUnreferenced() { return fDeleteWhenUnreferenced; }
00075 
00076 protected:
00077   ServerMediaSession(UsageEnvironment& env, char const* streamName,
00078                      char const* info, char const* description,
00079                      Boolean isSSM, char const* miscSDPLines);
00080   // called only by "createNew()"
00081 
00082 private: // redefined virtual functions
00083   virtual Boolean isServerMediaSession() const;
00084 
00085 private:
00086   Boolean fIsSSM;
00087 
00088   // Linkage fields:
00089   friend class ServerMediaSubsessionIterator;
00090   ServerMediaSubsession* fSubsessionsHead;
00091   ServerMediaSubsession* fSubsessionsTail;
00092   unsigned fSubsessionCounter;
00093 
00094   char* fStreamName;
00095   char* fInfoSDPString;
00096   char* fDescriptionSDPString;
00097   char* fMiscSDPLines;
00098   struct timeval fCreationTime;
00099   unsigned fReferenceCount;
00100   Boolean fDeleteWhenUnreferenced;
00101 };
00102 
00103 
00104 class ServerMediaSubsessionIterator {
00105 public:
00106   ServerMediaSubsessionIterator(ServerMediaSession& session);
00107   virtual ~ServerMediaSubsessionIterator();
00108 
00109   ServerMediaSubsession* next(); // NULL if none
00110   void reset();
00111 
00112 private:
00113   ServerMediaSession& fOurSession;
00114   ServerMediaSubsession* fNextPtr;
00115 };
00116 
00117 
00118 class ServerMediaSubsession: public Medium {
00119 public:
00120   virtual ~ServerMediaSubsession();
00121 
00122   unsigned trackNumber() const { return fTrackNumber; }
00123   char const* trackId();
00124   virtual char const* sdpLines() = 0;
00125   virtual void getStreamParameters(unsigned clientSessionId, // in
00126                                    netAddressBits clientAddress, // in
00127                                    Port const& clientRTPPort, // in
00128                                    Port const& clientRTCPPort, // in
00129                                    int tcpSocketNum, // in (-1 means use UDP, not TCP)
00130                                    unsigned char rtpChannelId, // in (used if TCP)
00131                                    unsigned char rtcpChannelId, // in (used if TCP)
00132                                    netAddressBits& destinationAddress, // in out
00133                                    u_int8_t& destinationTTL, // in out
00134                                    Boolean& isMulticast, // out
00135                                    Port& serverRTPPort, // out
00136                                    Port& serverRTCPPort, // out
00137                                    void*& streamToken // out
00138                                    ) = 0;
00139   virtual void startStream(unsigned clientSessionId, void* streamToken,
00140                            TaskFunc* rtcpRRHandler,
00141                            void* rtcpRRHandlerClientData,
00142                            unsigned short& rtpSeqNum,
00143                            unsigned& rtpTimestamp,
00144                            ServerRequestAlternativeByteHandler* serverRequestAlternativeByteHandler,
00145                            void* serverRequestAlternativeByteHandlerClientData) = 0;
00146   virtual void pauseStream(unsigned clientSessionId, void* streamToken);
00147   virtual void seekStream(unsigned clientSessionId, void* streamToken, double& seekNPT, double streamDuration, u_int64_t& numBytes);
00148      // "streamDuration", if >0.0, specifies how much data to stream, past "seekNPT".  (If <=0.0, all remaining data is streamed.)
00149      // "numBytes" returns the size (in bytes) of the data to be streamed, or 0 if unknown or unlimited.
00150   virtual void setStreamScale(unsigned clientSessionId, void* streamToken, float scale);
00151   virtual FramedSource* getStreamSource(void* streamToken);
00152   virtual void deleteStream(unsigned clientSessionId, void*& streamToken);
00153 
00154   virtual void testScaleFactor(float& scale); // sets "scale" to the actual supported scale
00155   virtual float duration() const;
00156     // returns 0 for an unbounded session (the default)
00157     // returns > 0 for a bounded session
00158 
00159   // The following may be called by (e.g.) SIP servers, for which the
00160   // address and port number fields in SDP descriptions need to be non-zero:
00161   void setServerAddressAndPortForSDP(netAddressBits addressBits,
00162                                      portNumBits portBits);
00163 
00164 protected: // we're a virtual base class
00165   ServerMediaSubsession(UsageEnvironment& env);
00166 
00167   char const* rangeSDPLine() const;
00168       // returns a string to be delete[]d
00169 
00170   ServerMediaSession* fParentSession;
00171   netAddressBits fServerAddressForSDP;
00172   portNumBits fPortNumForSDP;
00173 
00174 private:
00175   friend class ServerMediaSession;
00176   friend class ServerMediaSubsessionIterator;
00177   ServerMediaSubsession* fNext;
00178 
00179   unsigned fTrackNumber; // within an enclosing ServerMediaSession
00180   char const* fTrackId;
00181 };
00182 
00183 #endif

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