1 /* 2 * libjingle 3 * Copyright 2011 Google Inc. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright notice, 9 * this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright notice, 11 * this list of conditions and the following disclaimer in the documentation 12 * and/or other materials provided with the distribution. 13 * 3. The name of the author may not be used to endorse or promote products 14 * derived from this software without specific prior written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 17 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 18 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO 19 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 20 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 22 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 23 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 24 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 25 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28 // This file contains structures for describing SSRCs from a media source such 29 // as a MediaStreamTrack when it is sent across an RTP session. Multiple media 30 // sources may be sent across the same RTP session, each of them will be 31 // described by one StreamParams object 32 // SsrcGroup is used to describe the relationship between the SSRCs that 33 // are used for this media source. 34 // E.x: Consider a source that is sent as 3 simulcast streams 35 // Let the simulcast elements have SSRC 10, 20, 30. 36 // Let each simulcast element use FEC and let the protection packets have 37 // SSRC 11,21,31. 38 // To describe this 4 SsrcGroups are needed, 39 // StreamParams would then contain ssrc = {10,11,20,21,30,31} and 40 // ssrc_groups = {{SIM,{10,20,30}, {FEC,{10,11}, {FEC, {20,21}, {FEC {30,31}}} 41 // Please see RFC 5576. 42 43 #ifndef TALK_MEDIA_BASE_STREAMPARAMS_H_ 44 #define TALK_MEDIA_BASE_STREAMPARAMS_H_ 45 46 #include <algorithm> 47 #include <string> 48 #include <set> 49 #include <vector> 50 51 #include "talk/base/basictypes.h" 52 53 namespace cricket { 54 55 extern const char kFecSsrcGroupSemantics[]; 56 extern const char kFidSsrcGroupSemantics[]; 57 extern const char kSimSsrcGroupSemantics[]; 58 59 struct SsrcGroup { SsrcGroupSsrcGroup60 SsrcGroup(const std::string& usage, const std::vector<uint32>& ssrcs) 61 : semantics(usage), ssrcs(ssrcs) { 62 } 63 64 bool operator==(const SsrcGroup& other) const { 65 return (semantics == other.semantics && ssrcs == other.ssrcs); 66 } 67 bool operator!=(const SsrcGroup &other) const { 68 return !(*this == other); 69 } 70 71 bool has_semantics(const std::string& semantics) const; 72 73 std::string ToString() const; 74 75 std::string semantics; // e.g FIX, FEC, SIM. 76 std::vector<uint32> ssrcs; // SSRCs of this type. 77 }; 78 79 struct StreamParams { CreateLegacyStreamParams80 static StreamParams CreateLegacy(uint32 ssrc) { 81 StreamParams stream; 82 stream.ssrcs.push_back(ssrc); 83 return stream; 84 } 85 86 bool operator==(const StreamParams& other) const { 87 return (groupid == other.groupid && 88 id == other.id && 89 ssrcs == other.ssrcs && 90 ssrc_groups == other.ssrc_groups && 91 type == other.type && 92 display == other.display && 93 cname == other.cname && 94 sync_label == other.sync_label); 95 } 96 bool operator!=(const StreamParams &other) const { 97 return !(*this == other); 98 } 99 first_ssrcStreamParams100 uint32 first_ssrc() const { 101 if (ssrcs.empty()) { 102 return 0; 103 } 104 105 return ssrcs[0]; 106 } has_ssrcsStreamParams107 bool has_ssrcs() const { 108 return !ssrcs.empty(); 109 } has_ssrcStreamParams110 bool has_ssrc(uint32 ssrc) const { 111 return std::find(ssrcs.begin(), ssrcs.end(), ssrc) != ssrcs.end(); 112 } add_ssrcStreamParams113 void add_ssrc(uint32 ssrc) { 114 ssrcs.push_back(ssrc); 115 } has_ssrc_groupsStreamParams116 bool has_ssrc_groups() const { 117 return !ssrc_groups.empty(); 118 } has_ssrc_groupStreamParams119 bool has_ssrc_group(const std::string& semantics) const { 120 return (get_ssrc_group(semantics) != NULL); 121 } get_ssrc_groupStreamParams122 const SsrcGroup* get_ssrc_group(const std::string& semantics) const { 123 for (std::vector<SsrcGroup>::const_iterator it = ssrc_groups.begin(); 124 it != ssrc_groups.end(); ++it) { 125 if (it->has_semantics(semantics)) { 126 return &(*it); 127 } 128 } 129 return NULL; 130 } 131 132 // Convenience function to add an FID ssrc for a primary_ssrc 133 // that's already been added. AddFidSsrcStreamParams134 inline bool AddFidSsrc(uint32 primary_ssrc, uint32 fid_ssrc) { 135 return AddSecondarySsrc(kFidSsrcGroupSemantics, primary_ssrc, fid_ssrc); 136 } 137 138 // Convenience function to lookup the FID ssrc for a primary_ssrc. 139 // Returns false if primary_ssrc not found or FID not defined for it. GetFidSsrcStreamParams140 inline bool GetFidSsrc(uint32 primary_ssrc, uint32* fid_ssrc) const { 141 return GetSecondarySsrc(kFidSsrcGroupSemantics, primary_ssrc, fid_ssrc); 142 } 143 144 std::string ToString() const; 145 146 // Resource of the MUC jid of the participant of with this stream. 147 // For 1:1 calls, should be left empty (which means remote streams 148 // and local streams should not be mixed together). 149 std::string groupid; 150 // Unique per-groupid, not across all groupids 151 std::string id; 152 std::vector<uint32> ssrcs; // All SSRCs for this source 153 std::vector<SsrcGroup> ssrc_groups; // e.g. FID, FEC, SIM 154 // Examples: "camera", "screencast" 155 std::string type; 156 // Friendly name describing stream 157 std::string display; 158 std::string cname; // RTCP CNAME 159 std::string sync_label; // Friendly name of cname. 160 161 private: 162 bool AddSecondarySsrc(const std::string& semantics, uint32 primary_ssrc, 163 uint32 secondary_ssrc); 164 bool GetSecondarySsrc(const std::string& semantics, uint32 primary_ssrc, 165 uint32* secondary_ssrc) const; 166 }; 167 168 // A Stream can be selected by either groupid+id or ssrc. 169 struct StreamSelector { StreamSelectorStreamSelector170 explicit StreamSelector(uint32 ssrc) : 171 ssrc(ssrc) { 172 } 173 StreamSelectorStreamSelector174 StreamSelector(const std::string& groupid, 175 const std::string& streamid) : 176 ssrc(0), 177 groupid(groupid), 178 streamid(streamid) { 179 } 180 MatchesStreamSelector181 bool Matches(const StreamParams& stream) const { 182 if (ssrc == 0) { 183 return stream.groupid == groupid && stream.id == streamid; 184 } else { 185 return stream.has_ssrc(ssrc); 186 } 187 } 188 189 uint32 ssrc; 190 std::string groupid; 191 std::string streamid; 192 }; 193 194 typedef std::vector<StreamParams> StreamParamsVec; 195 196 // Finds the stream in streams. Returns true if found. 197 bool GetStream(const StreamParamsVec& streams, 198 const StreamSelector& selector, 199 StreamParams* stream_out); 200 bool GetStreamBySsrc(const StreamParamsVec& streams, uint32 ssrc, 201 StreamParams* stream_out); 202 bool GetStreamByIds(const StreamParamsVec& streams, 203 const std::string& groupid, 204 const std::string& id, 205 StreamParams* stream_out); 206 207 // Removes the stream from streams. Returns true if a stream is 208 // found and removed. 209 bool RemoveStream(StreamParamsVec* streams, 210 const StreamSelector& selector); 211 bool RemoveStreamBySsrc(StreamParamsVec* streams, uint32 ssrc); 212 bool RemoveStreamByIds(StreamParamsVec* streams, 213 const std::string& groupid, 214 const std::string& id); 215 216 // Checks if |sp| defines parameters for a single primary stream. There may 217 // be an RTX stream associated with the primary stream. Leaving as non-static so 218 // we can test this function. 219 bool IsOneSsrcStream(const StreamParams& sp); 220 221 // Checks if |sp| defines parameters for one Simulcast stream. There may be RTX 222 // streams associated with the simulcast streams. Leaving as non-static so we 223 // can test this function. 224 bool IsSimulcastStream(const StreamParams& sp); 225 226 } // namespace cricket 227 228 #endif // TALK_MEDIA_BASE_STREAMPARAMS_H_ 229