Boolean MediaSession::initializeWithSDP(char const* sdpDescription) { if (sdpDescription == NULL) return False; // Begin by processing all SDP lines until we see the first "m=" char const* sdpLine = sdpDescription; char const* nextSDPLine; while (1) { if (!parseSDPLine(sdpLine, nextSDPLine)) return False; //##### We should really check for: // - "a=control:" attributes (to set the URL for aggregate control) // - the correct SDP version (v=0) if (sdpLine[0] == 'm') break; sdpLine = nextSDPLine; if (sdpLine == NULL) break; // there are no m= lines at all // Check for various special SDP lines that we understand: if (parseSDPLine_s(sdpLine)) continue; if (parseSDPLine_i(sdpLine)) continue; if (parseSDPLine_c(sdpLine)) continue; if (parseSDPAttribute_control(sdpLine)) continue; if (parseSDPAttribute_range(sdpLine)) continue; if (parseSDPAttribute_type(sdpLine)) continue; if (parseSDPAttribute_source_filter(sdpLine)) continue; #ifdef SUPPORT_REAL_RTSP if (RealParseSDPAttributes(this, sdpLine)) continue; #endif } while (sdpLine != NULL) { // We have a "m=" line, representing a new sub-session: MediaSubsession* subsession = new MediaSubsession(*this); if (subsession == NULL) { envir().setResultMsg("Unable to create new MediaSubsession"); return False; } // Parse the line as "m=<medium_name> <client_portNum> RTP/AVP <fmt>" // or "m=<medium_name> <client_portNum>/<num_ports> RTP/AVP <fmt>" // (Should we be checking for >1 payload format number here?)##### char* mediumName = strDupSize(sdpLine); // ensures we have enough space char* protocolName = NULL; unsigned payloadFormat; if ((sscanf(sdpLine, "m=%s %hu RTP/AVP %u", mediumName, &subsession->fClientPortNum, &payloadFormat) == 3 || sscanf(sdpLine, "m=%s %hu/%*u RTP/AVP %u", mediumName, &subsession->fClientPortNum, &payloadFormat) == 3) && payloadFormat <= 127) { protocolName = "RTP"; } else if ((sscanf(sdpLine, "m=%s %hu UDP %u", mediumName, &subsession->fClientPortNum, &payloadFormat) == 3 || sscanf(sdpLine, "m=%s %hu udp %u", mediumName, &subsession->fClientPortNum, &payloadFormat) == 3 || sscanf(sdpLine, "m=%s %hu RAW/RAW/UDP %u", mediumName, &subsession->fClientPortNum, &payloadFormat) == 3) && payloadFormat <= 127) { // This is a RAW UDP source protocolName = "UDP"; } else { // This "m=" line is bad; output an error message saying so: char* sdpLineStr; if (nextSDPLine == NULL) { sdpLineStr = (char*)sdpLine; } else { sdpLineStr = strDup(sdpLine); sdpLineStr[nextSDPLine-sdpLine] = '\0'; } envir() << "Bad SDP \"m=\" line: " << sdpLineStr << "\n"; if (sdpLineStr != (char*)sdpLine) delete[] sdpLineStr; delete[] mediumName; delete subsession; // Skip the following SDP lines, up until the next "m=": while (1) { sdpLine = nextSDPLine; if (sdpLine == NULL) break; // we've reached the end if (!parseSDPLine(sdpLine, nextSDPLine)) return False; if (sdpLine[0] == 'm') break; // we've reached the next subsession } continue; } // Insert this subsession at the end of the list: if (fSubsessionsTail == NULL) { fSubsessionsHead = fSubsessionsTail = subsession; } else { fSubsessionsTail->setNext(subsession); fSubsessionsTail = subsession; } subsession->serverPortNum = subsession->fClientPortNum; // by default char const* mStart = sdpLine; subsession->fSavedSDPLines = strDup(mStart); subsession->fMediumName = strDup(mediumName); delete[] mediumName; subsession->fProtocolName = strDup(protocolName); subsession->fRTPPayloadFormat = payloadFormat; // Process the following SDP lines, up until the next "m=": while (1) { sdpLine = nextSDPLine; if (sdpLine == NULL) break; // we've reached the end if (!parseSDPLine(sdpLine, nextSDPLine)) return False; if (sdpLine[0] == 'm') break; // we've reached the next subsession // Check for various special SDP lines that we understand: if (subsession->parseSDPLine_c(sdpLine)) continue; if (subsession->parseSDPAttribute_rtpmap(sdpLine)) continue; if (subsession->parseSDPAttribute_control(sdpLine)) continue; if (subsession->parseSDPAttribute_range(sdpLine)) continue; if (subsession->parseSDPAttribute_fmtp(sdpLine)) continue; if (subsession->parseSDPAttribute_source_filter(sdpLine)) continue; if (subsession->parseSDPAttribute_x_dimensions(sdpLine)) continue; if (subsession->parseSDPAttribute_framerate(sdpLine)) continue; if ( subsession->parseSDPAttribute_bandwidth( sdpLine ) ) { continue; } #ifdef SUPPORT_REAL_RTSP if (RealParseSDPAttributes(subsession, sdpLine)) continue; #endif // (Later, check for malformed lines, and other valid SDP lines#####) } if (sdpLine != NULL) subsession->fSavedSDPLines[sdpLine-mStart] = '\0'; // If we don't yet know the codec name, try looking it up from the // list of static payload types: if (subsession->fCodecName == NULL) { subsession->fCodecName = lookupPayloadFormat(subsession->fRTPPayloadFormat, subsession->fRTPTimestampFrequency, subsession->fNumChannels); if (subsession->fCodecName == NULL) { char typeStr[20]; sprintf(typeStr, "%d", subsession->fRTPPayloadFormat); envir().setResultMsg("Unknown codec name for RTP payload type ", typeStr); return False; } } // If we don't yet know this subsession's RTP timestamp frequency // (because it uses a dynamic payload type and the corresponding // SDP "rtpmap" attribute erroneously didn't specify it), // then guess it now: if (subsession->fRTPTimestampFrequency == 0) { subsession->fRTPTimestampFrequency = guessRTPTimestampFrequency(subsession->fMediumName, subsession->fCodecName); } } return True; }