talk/media/base/streamparams.h - src - Git at Google

 /*
  * libjingle
  * Copyright 2011 Google Inc.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
  *
  *  1. Redistributions of source code must retain the above copyright notice,
  *     this list of conditions and the following disclaimer.
  *  2. Redistributions in binary form must reproduce the above copyright notice,
  *     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.
  *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
  * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */

 // 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_MEDIA_BASE_STREAMPARAMS_H_
 #define TALK_MEDIA_BASE_STREAMPARAMS_H_

 #include <algorithm>
 #include <set>
 #include <string>
 #include <vector>

 #include "webrtc/base/basictypes.h"
 #include "webrtc/base/constructormagic.h"

 namespace cricket {

 extern const char kFecSsrcGroupSemantics[];
 extern const char kFidSsrcGroupSemantics[];
 extern const char kSimSsrcGroupSemantics[];

 struct SsrcGroup {
   SsrcGroup(const std::string& usage, const std::vector<uint32_t>& 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);
   }

   bool has_semantics(const std::string& semantics) const;

   std::string ToString() const;

   std::string semantics;  // e.g FIX, FEC, SIM.
   std::vector<uint32_t> ssrcs;  // SSRCs of this type.
 };

 struct StreamParams {
   static StreamParams CreateLegacy(uint32_t ssrc) {
     StreamParams stream;
     stream.ssrcs.push_back(ssrc);
     return stream;
   }

   bool operator==(const StreamParams& other) const {
     return (groupid == other.groupid &&
             id == other.id &&
             ssrcs == other.ssrcs &&
             ssrc_groups == other.ssrc_groups &&
             type == other.type &&
             display == other.display &&
             cname == other.cname &&
             sync_label == other.sync_label);
   }
   bool operator!=(const StreamParams &other) const {
     return !(*this == other);
   }

   uint32_t first_ssrc() const {
     if (ssrcs.empty()) {
       return 0;
     }

     return ssrcs[0];
   }
   bool has_ssrcs() const {
     return !ssrcs.empty();
   }
   bool has_ssrc(uint32_t ssrc) const {
     return std::find(ssrcs.begin(), ssrcs.end(), ssrc) != ssrcs.end();
   }
   void add_ssrc(uint32_t ssrc) { ssrcs.push_back(ssrc); }
   bool has_ssrc_groups() const {
     return !ssrc_groups.empty();
   }
   bool has_ssrc_group(const std::string& semantics) const {
     return (get_ssrc_group(semantics) != NULL);
   }
   const SsrcGroup* get_ssrc_group(const std::string& semantics) const {
     for (std::vector<SsrcGroup>::const_iterator it = ssrc_groups.begin();
          it != ssrc_groups.end(); ++it) {
       if (it->has_semantics(semantics)) {
         return &(*it);
       }
     }
     return NULL;
   }

   // Convenience function to add an FID ssrc for a primary_ssrc
   // that's already been added.
   inline bool AddFidSsrc(uint32_t primary_ssrc, uint32_t fid_ssrc) {
     return AddSecondarySsrc(kFidSsrcGroupSemantics, primary_ssrc, fid_ssrc);
   }

   // Convenience function to lookup the FID ssrc for a primary_ssrc.
   // Returns false if primary_ssrc not found or FID not defined for it.
   inline bool GetFidSsrc(uint32_t primary_ssrc, uint32_t* fid_ssrc) const {
     return GetSecondarySsrc(kFidSsrcGroupSemantics, primary_ssrc, fid_ssrc);
   }

   // Convenience to get all the SIM SSRCs if there are SIM ssrcs, or
   // the first SSRC otherwise.
   void GetPrimarySsrcs(std::vector<uint32_t>* ssrcs) const;

   // Convenience to get all the FID SSRCs for the given primary ssrcs.
   // If a given primary SSRC does not have a FID SSRC, the list of FID
   // SSRCS will be smaller than the list of primary SSRCs.
   void GetFidSsrcs(const std::vector<uint32_t>& primary_ssrcs,
                    std::vector<uint32_t>* fid_ssrcs) const;

   std::string ToString() const;

   // 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 groupid;
   // Unique per-groupid, not across all groupids
   std::string id;
   std::vector<uint32_t> 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.

  private:
   bool AddSecondarySsrc(const std::string& semantics,
                         uint32_t primary_ssrc,
                         uint32_t secondary_ssrc);
   bool GetSecondarySsrc(const std::string& semantics,
                         uint32_t primary_ssrc,
                         uint32_t* secondary_ssrc) const;
 };

 // A Stream can be selected by either groupid+id or ssrc.
 struct StreamSelector {
   explicit StreamSelector(uint32_t ssrc) : ssrc(ssrc) {}

   StreamSelector(const std::string& groupid,
                  const std::string& streamid) :
       ssrc(0),
       groupid(groupid),
       streamid(streamid) {
   }

   bool Matches(const StreamParams& stream) const {
     if (ssrc == 0) {
       return stream.groupid == groupid && stream.id == streamid;
     } else {
       return stream.has_ssrc(ssrc);
     }
   }

   uint32_t ssrc;
   std::string groupid;
   std::string streamid;
 };

 typedef std::vector<StreamParams> StreamParamsVec;

 // A collection of audio and video and data streams. Most of the
 // methods are merely for convenience. Many of these methods are keyed
 // by ssrc, which is the source identifier in the RTP spec
 // (http://tools.ietf.org/html/rfc3550).
 // TODO(pthatcher):  Add basic unit test for these.
 // See https://code.google.com/p/webrtc/issues/detail?id=4107
 struct MediaStreams {
  public:
   MediaStreams() {}
   void CopyFrom(const MediaStreams& sources);

   bool empty() const {
     return audio_.empty() && video_.empty() && data_.empty();
   }

   std::vector<StreamParams>* mutable_audio() { return &audio_; }
   std::vector<StreamParams>* mutable_video() { return &video_; }
   std::vector<StreamParams>* mutable_data() { return &data_; }
   const std::vector<StreamParams>& audio() const { return audio_; }
   const std::vector<StreamParams>& video() const { return video_; }
   const std::vector<StreamParams>& data() const { return data_; }

   // Gets a stream, returning true if found.
   bool GetAudioStream(
       const StreamSelector& selector, StreamParams* stream);
   bool GetVideoStream(
       const StreamSelector& selector, StreamParams* stream);
   bool GetDataStream(
       const StreamSelector& selector, StreamParams* stream);
   // Adds a stream.
   void AddAudioStream(const StreamParams& stream);
   void AddVideoStream(const StreamParams& stream);
   void AddDataStream(const StreamParams& stream);
   // Removes a stream, returning true if found and removed.
   bool RemoveAudioStream(const StreamSelector& selector);
   bool RemoveVideoStream(const StreamSelector& selector);
   bool RemoveDataStream(const StreamSelector& selector);

  private:
   std::vector<StreamParams> audio_;
   std::vector<StreamParams> video_;
   std::vector<StreamParams> data_;

   RTC_DISALLOW_COPY_AND_ASSIGN(MediaStreams);
 };

 // A request for a specific format of a specific stream.
 struct StaticVideoView {
   StaticVideoView(const StreamSelector& selector,
                   int width, int height, int framerate)
       : selector(selector),
         width(width),
         height(height),
         framerate(framerate),
         preference(0) {
   }

   StreamSelector selector;
   int width;
   int height;
   int framerate;
   int preference;
 };

 typedef std::vector<StaticVideoView> StaticVideoViews;

 // A request for several streams in various formats.
 struct ViewRequest {
   StaticVideoViews static_video_views;
 };

 template <class Condition>
 const StreamParams* GetStream(const StreamParamsVec& streams,
                               Condition condition) {
   StreamParamsVec::const_iterator found =
       std::find_if(streams.begin(), streams.end(), condition);
   return found == streams.end() ? nullptr : &(*found);
 }

 inline const StreamParams* GetStreamBySsrc(const StreamParamsVec& streams,
                                            uint32_t ssrc) {
   return GetStream(streams,
       [&ssrc](const StreamParams& sp) { return sp.has_ssrc(ssrc); });
 }

 inline const StreamParams* GetStreamByIds(const StreamParamsVec& streams,
                                           const std::string& groupid,
                                           const std::string& id) {
   return GetStream(streams,
       [&groupid, &id](const StreamParams& sp) {
         return sp.groupid == groupid && sp.id == id;
       });
 }

 inline const StreamParams* GetStream(const StreamParamsVec& streams,
                                      const StreamSelector& selector) {
   return GetStream(streams,
       [&selector](const StreamParams& sp) { return selector.Matches(sp); });
 }

 template <class Condition>
 bool RemoveStream(StreamParamsVec* streams, Condition condition) {
   auto iter(std::remove_if(streams->begin(), streams->end(), condition));
   if (iter == streams->end())
     return false;
   streams->erase(iter, streams->end());
   return true;
 }

 // Removes the stream from streams. Returns true if a stream is
 // found and removed.
 inline bool RemoveStream(StreamParamsVec* streams,
                   const StreamSelector& selector) {
   return RemoveStream(streams,
       [&selector](const StreamParams& sp) { return selector.Matches(sp); });
 }
 inline bool RemoveStreamBySsrc(StreamParamsVec* streams, uint32_t ssrc) {
   return RemoveStream(streams,
       [&ssrc](const StreamParams& sp) { return sp.has_ssrc(ssrc); });
 }
 inline bool RemoveStreamByIds(StreamParamsVec* streams,
                               const std::string& groupid,
                               const std::string& id) {
   return RemoveStream(streams,
       [&groupid, &id](const StreamParams& sp) {
         return sp.groupid == groupid && sp.id == id;
       });
 }

 // Checks if |sp| defines parameters for a single primary stream. There may
 // be an RTX stream associated with the primary stream. Leaving as non-static so
 // we can test this function.
 bool IsOneSsrcStream(const StreamParams& sp);

 // Checks if |sp| defines parameters for one Simulcast stream. There may be RTX
 // streams associated with the simulcast streams. Leaving as non-static so we
 // can test this function.
 bool IsSimulcastStream(const StreamParams& sp);

 }  // namespace cricket

 #endif  // TALK_MEDIA_BASE_STREAMPARAMS_H_
	/*
	* libjingle
	* Copyright 2011 Google Inc.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions are met:
	*
	* 1. Redistributions of source code must retain the above copyright notice,
	* this list of conditions and the following disclaimer.
	* 2. Redistributions in binary form must reproduce the above copyright notice,
	* 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.
	*
	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
	* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
	* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
	* EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
	* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
	* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
	* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
	* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
	* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	*/

	// 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_MEDIA_BASE_STREAMPARAMS_H_
	#define TALK_MEDIA_BASE_STREAMPARAMS_H_

	#include <algorithm>
	#include <set>
	#include <string>
	#include <vector>

	#include "webrtc/base/basictypes.h"
	#include "webrtc/base/constructormagic.h"

	namespace cricket {

	extern const char kFecSsrcGroupSemantics[];
	extern const char kFidSsrcGroupSemantics[];
	extern const char kSimSsrcGroupSemantics[];

	struct SsrcGroup {
	SsrcGroup(const std::string& usage, const std::vector<uint32_t>& 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);
	}

	bool has_semantics(const std::string& semantics) const;

	std::string ToString() const;

	std::string semantics; // e.g FIX, FEC, SIM.
	std::vector<uint32_t> ssrcs; // SSRCs of this type.
	};

	struct StreamParams {
	static StreamParams CreateLegacy(uint32_t ssrc) {
	StreamParams stream;
	stream.ssrcs.push_back(ssrc);
	return stream;
	}

	bool operator==(const StreamParams& other) const {
	return (groupid == other.groupid &&
	id == other.id &&
	ssrcs == other.ssrcs &&
	ssrc_groups == other.ssrc_groups &&
	type == other.type &&
	display == other.display &&
	cname == other.cname &&
	sync_label == other.sync_label);
	}
	bool operator!=(const StreamParams &other) const {
	return !(*this == other);
	}

	uint32_t first_ssrc() const {
	if (ssrcs.empty()) {
	return 0;
	}

	return ssrcs[0];
	}
	bool has_ssrcs() const {
	return !ssrcs.empty();
	}
	bool has_ssrc(uint32_t ssrc) const {
	return std::find(ssrcs.begin(), ssrcs.end(), ssrc) != ssrcs.end();
	}
	void add_ssrc(uint32_t ssrc) { ssrcs.push_back(ssrc); }
	bool has_ssrc_groups() const {
	return !ssrc_groups.empty();
	}
	bool has_ssrc_group(const std::string& semantics) const {
	return (get_ssrc_group(semantics) != NULL);
	}
	const SsrcGroup* get_ssrc_group(const std::string& semantics) const {
	for (std::vector<SsrcGroup>::const_iterator it = ssrc_groups.begin();
	it != ssrc_groups.end(); ++it) {
	if (it->has_semantics(semantics)) {
	return &(*it);
	}
	}
	return NULL;
	}

	// Convenience function to add an FID ssrc for a primary_ssrc
	// that's already been added.
	inline bool AddFidSsrc(uint32_t primary_ssrc, uint32_t fid_ssrc) {
	return AddSecondarySsrc(kFidSsrcGroupSemantics, primary_ssrc, fid_ssrc);
	}

	// Convenience function to lookup the FID ssrc for a primary_ssrc.
	// Returns false if primary_ssrc not found or FID not defined for it.
	inline bool GetFidSsrc(uint32_t primary_ssrc, uint32_t* fid_ssrc) const {
	return GetSecondarySsrc(kFidSsrcGroupSemantics, primary_ssrc, fid_ssrc);
	}

	// Convenience to get all the SIM SSRCs if there are SIM ssrcs, or
	// the first SSRC otherwise.
	void GetPrimarySsrcs(std::vector<uint32_t>* ssrcs) const;

	// Convenience to get all the FID SSRCs for the given primary ssrcs.
	// If a given primary SSRC does not have a FID SSRC, the list of FID
	// SSRCS will be smaller than the list of primary SSRCs.
	void GetFidSsrcs(const std::vector<uint32_t>& primary_ssrcs,
	std::vector<uint32_t>* fid_ssrcs) const;

	std::string ToString() const;

	// 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 groupid;
	// Unique per-groupid, not across all groupids
	std::string id;
	std::vector<uint32_t> 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.

	private:
	bool AddSecondarySsrc(const std::string& semantics,
	uint32_t primary_ssrc,
	uint32_t secondary_ssrc);
	bool GetSecondarySsrc(const std::string& semantics,
	uint32_t primary_ssrc,
	uint32_t* secondary_ssrc) const;
	};

	// A Stream can be selected by either groupid+id or ssrc.
	struct StreamSelector {
	explicit StreamSelector(uint32_t ssrc) : ssrc(ssrc) {}

	StreamSelector(const std::string& groupid,
	const std::string& streamid) :
	ssrc(0),
	groupid(groupid),
	streamid(streamid) {
	}

	bool Matches(const StreamParams& stream) const {
	if (ssrc == 0) {
	return stream.groupid == groupid && stream.id == streamid;
	} else {
	return stream.has_ssrc(ssrc);
	}
	}

	uint32_t ssrc;
	std::string groupid;
	std::string streamid;
	};

	typedef std::vector<StreamParams> StreamParamsVec;

	// A collection of audio and video and data streams. Most of the
	// methods are merely for convenience. Many of these methods are keyed
	// by ssrc, which is the source identifier in the RTP spec
	// (http://tools.ietf.org/html/rfc3550).
	// TODO(pthatcher): Add basic unit test for these.
	// See https://code.google.com/p/webrtc/issues/detail?id=4107
	struct MediaStreams {
	public:
	MediaStreams() {}
	void CopyFrom(const MediaStreams& sources);

	bool empty() const {
	return audio_.empty() && video_.empty() && data_.empty();
	}

	std::vector<StreamParams>* mutable_audio() { return &audio_; }
	std::vector<StreamParams>* mutable_video() { return &video_; }
	std::vector<StreamParams>* mutable_data() { return &data_; }
	const std::vector<StreamParams>& audio() const { return audio_; }
	const std::vector<StreamParams>& video() const { return video_; }
	const std::vector<StreamParams>& data() const { return data_; }

	// Gets a stream, returning true if found.
	bool GetAudioStream(
	const StreamSelector& selector, StreamParams* stream);
	bool GetVideoStream(
	const StreamSelector& selector, StreamParams* stream);
	bool GetDataStream(
	const StreamSelector& selector, StreamParams* stream);
	// Adds a stream.
	void AddAudioStream(const StreamParams& stream);
	void AddVideoStream(const StreamParams& stream);
	void AddDataStream(const StreamParams& stream);
	// Removes a stream, returning true if found and removed.
	bool RemoveAudioStream(const StreamSelector& selector);
	bool RemoveVideoStream(const StreamSelector& selector);
	bool RemoveDataStream(const StreamSelector& selector);

	private:
	std::vector<StreamParams> audio_;
	std::vector<StreamParams> video_;
	std::vector<StreamParams> data_;

	RTC_DISALLOW_COPY_AND_ASSIGN(MediaStreams);
	};

	// A request for a specific format of a specific stream.
	struct StaticVideoView {
	StaticVideoView(const StreamSelector& selector,
	int width, int height, int framerate)
	: selector(selector),
	width(width),
	height(height),
	framerate(framerate),
	preference(0) {
	}

	StreamSelector selector;
	int width;
	int height;
	int framerate;
	int preference;
	};

	typedef std::vector<StaticVideoView> StaticVideoViews;

	// A request for several streams in various formats.
	struct ViewRequest {
	StaticVideoViews static_video_views;
	};

	template <class Condition>
	const StreamParams* GetStream(const StreamParamsVec& streams,
	Condition condition) {
	StreamParamsVec::const_iterator found =
	std::find_if(streams.begin(), streams.end(), condition);
	return found == streams.end() ? nullptr : &(*found);
	}

	inline const StreamParams* GetStreamBySsrc(const StreamParamsVec& streams,
	uint32_t ssrc) {
	return GetStream(streams,
	[&ssrc](const StreamParams& sp) { return sp.has_ssrc(ssrc); });
	}

	inline const StreamParams* GetStreamByIds(const StreamParamsVec& streams,
	const std::string& groupid,
	const std::string& id) {
	return GetStream(streams,
	[&groupid, &id](const StreamParams& sp) {
	return sp.groupid == groupid && sp.id == id;
	});
	}

	inline const StreamParams* GetStream(const StreamParamsVec& streams,
	const StreamSelector& selector) {
	return GetStream(streams,
	[&selector](const StreamParams& sp) { return selector.Matches(sp); });
	}

	template <class Condition>
	bool RemoveStream(StreamParamsVec* streams, Condition condition) {
	auto iter(std::remove_if(streams->begin(), streams->end(), condition));
	if (iter == streams->end())
	return false;
	streams->erase(iter, streams->end());
	return true;
	}

	// Removes the stream from streams. Returns true if a stream is
	// found and removed.
	inline bool RemoveStream(StreamParamsVec* streams,
	const StreamSelector& selector) {
	return RemoveStream(streams,
	[&selector](const StreamParams& sp) { return selector.Matches(sp); });
	}
	inline bool RemoveStreamBySsrc(StreamParamsVec* streams, uint32_t ssrc) {
	return RemoveStream(streams,
	[&ssrc](const StreamParams& sp) { return sp.has_ssrc(ssrc); });
	}
	inline bool RemoveStreamByIds(StreamParamsVec* streams,
	const std::string& groupid,
	const std::string& id) {
	return RemoveStream(streams,
	[&groupid, &id](const StreamParams& sp) {
	return sp.groupid == groupid && sp.id == id;
	});
	}

	// Checks if \|sp\| defines parameters for a single primary stream. There may
	// be an RTX stream associated with the primary stream. Leaving as non-static so
	// we can test this function.
	bool IsOneSsrcStream(const StreamParams& sp);

	// Checks if \|sp\| defines parameters for one Simulcast stream. There may be RTX
	// streams associated with the simulcast streams. Leaving as non-static so we
	// can test this function.
	bool IsSimulcastStream(const StreamParams& sp);

	} // namespace cricket

	#endif // TALK_MEDIA_BASE_STREAMPARAMS_H_