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 // CurrentSpeakerMonitor monitors the audio levels for a session and determines 29 // which participant is currently speaking. 30 31 #ifndef TALK_SESSION_MEDIA_CURRENTSPEAKERMONITOR_H_ 32 #define TALK_SESSION_MEDIA_CURRENTSPEAKERMONITOR_H_ 33 34 #include <map> 35 36 #include "talk/base/basictypes.h" 37 #include "talk/base/sigslot.h" 38 39 namespace cricket { 40 41 class BaseSession; 42 class Call; 43 class Session; 44 struct AudioInfo; 45 struct MediaStreams; 46 47 // Note that the call's audio monitor must be started before this is started. 48 // It's recommended that the audio monitor be started with a 100 ms period. 49 class CurrentSpeakerMonitor : public sigslot::has_slots<> { 50 public: 51 CurrentSpeakerMonitor(Call* call, BaseSession* session); 52 ~CurrentSpeakerMonitor(); 53 54 BaseSession* session() const { return session_; } 55 56 void Start(); 57 void Stop(); 58 59 // Used by tests. Note that the actual minimum time between switches 60 // enforced by the monitor will be the given value plus or minus the 61 // resolution of the system clock. 62 void set_min_time_between_switches(uint32 min_time_between_switches); 63 64 // This is fired when the current speaker changes, and provides his audio 65 // SSRC. This only fires after the audio monitor on the underlying Call has 66 // been started. 67 sigslot::signal2<CurrentSpeakerMonitor*, uint32> SignalUpdate; 68 69 private: 70 void OnAudioMonitor(Call* call, const AudioInfo& info); 71 void OnMediaStreamsUpdate(Call* call, 72 Session* session, 73 const MediaStreams& added, 74 const MediaStreams& removed); 75 76 // These are states that a participant will pass through so that we gradually 77 // recognize that they have started and stopped speaking. This avoids 78 // "twitchiness". 79 enum SpeakingState { 80 SS_NOT_SPEAKING, 81 SS_MIGHT_BE_SPEAKING, 82 SS_SPEAKING, 83 SS_WAS_SPEAKING_RECENTLY1, 84 SS_WAS_SPEAKING_RECENTLY2 85 }; 86 87 bool started_; 88 Call* call_; 89 BaseSession* session_; 90 std::map<uint32, SpeakingState> ssrc_to_speaking_state_map_; 91 uint32 current_speaker_ssrc_; 92 // To prevent overswitching, switching is disabled for some time after a 93 // switch is made. This gives us the earliest time a switch is permitted. 94 uint32 earliest_permitted_switch_time_; 95 uint32 min_time_between_switches_; 96 }; 97 98 } 99 100 #endif // TALK_SESSION_MEDIA_CURRENTSPEAKERMONITOR_H_ 101