talk/session/phone/streamparams.h

/*
 * libjingle
 * Copyright 2011, Google Inc.
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 * modification, are permitted provided that the following conditions are met:
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 *     this list of conditions and the following disclaimer in the documentation
 *     and/or other materials provided with the distribution.
 *  3. The name of the author may not be used to endorse or promote products
 *     derived from this software without specific prior written permission.
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 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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// This file contains structures for describing SSRCs from a media source such
// as a MediaStreamTrack when it is sent across an RTP session. Multiple media
// sources may be sent across the same RTP session, each of them will be
// described by one StreamParams object
// SsrcGroup is used to describe the relationship between the SSRCs that
// are used for this media source.
// E.x: Consider a source that is sent as 3 simulcast streams
// Let the simulcast elements have SSRC 10, 20, 30.
// Let each simulcast element use FEC and let the protection packets have
// SSRC 11,21,31.
// To describe this 4 SsrcGroups are needed,
// StreamParams would then contain ssrc = {10,11,20,21,30,31} and
// ssrc_groups = {{SIM,{10,20,30}, {FEC,{10,11}, {FEC, {20,21}, {FEC {30,31}}}
// Please see RFC 5576.

#ifndef TALK_SESSION_PHONE_STREAMPARAMS_H_
#define TALK_SESSION_PHONE_STREAMPARAMS_H_

#include <string>
#include <vector>

namespace cricket {

struct SsrcGroup {
  SsrcGroup(const std::string& usage, const std::vector<uint32>& ssrcs)
      : semantics(usage), ssrcs(ssrcs) {
  }

  bool operator==(const SsrcGroup& other) const {
    return (semantics == other.semantics && ssrcs == other.ssrcs);
  }
  bool operator!=(const SsrcGroup &other) const {
    return !(*this == other);
  }

  std::string semantics;  // e.g FIX, FEC, SIM.
  std::vector<uint32> ssrcs;  // SSRCs of this type.
};

struct StreamParams {
  static StreamParams CreateLegacy(uint32 ssrc) {
    StreamParams stream;
    stream.ssrcs.push_back(ssrc);
    return stream;
  }
  bool operator==(const StreamParams& other) const {
    return (nick == other.nick &&
            name == other.name &&
            ssrcs == other.ssrcs &&
            ssrc_groups == other.ssrc_groups &&
            type == other.type &&
            display == other.display &&
            cname == other.cname &&
            sync_label == sync_label);
  }
  bool operator!=(const StreamParams &other) const {
    return !(*this == other);
  }

  uint32 first_ssrc() const {
    if (ssrcs.empty()) {
      return 0;
    }

    return ssrcs[0];
  }
  bool has_ssrcs() const {
    return !ssrcs.empty();
  }

  // Resource of the MUC jid of the participant of with this stream.
  // For 1:1 calls, should be left empty (which means remote streams
  // and local streams should not be mixed together).
  std::string nick;
  // Unique name of this source (unique per-nick, not for all nicks)
  std::string name;
  std::vector<uint32> ssrcs;  // All SSRCs for this source
  std::vector<SsrcGroup> ssrc_groups;  // e.g. FID, FEC, SIM
  // Examples: "camera", "screencast"
  std::string type;
  // Friendly name describing stream
  std::string display;
  std::string cname;  // RTCP CNAME
  std::string sync_label;  // Friendly name of cname.
};

}  // namespace cricket

#endif  // TALK_SESSION_PHONE_STREAMPARAMS_H_