trunk/talk git-svn-id: http://webrtc.googlecode.com/svn/trunk@4318 4adac7df-926f-26a2-2b94-8c16560cd09d
		
			
				
	
	
		
			209 lines
		
	
	
		
			7.4 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			209 lines
		
	
	
		
			7.4 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
/*
 | 
						|
 * 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.
 | 
						|
 */
 | 
						|
 | 
						|
#include "talk/session/media/currentspeakermonitor.h"
 | 
						|
 | 
						|
#include "talk/base/logging.h"
 | 
						|
#include "talk/session/media/call.h"
 | 
						|
 | 
						|
namespace cricket {
 | 
						|
 | 
						|
namespace {
 | 
						|
const int kMaxAudioLevel = 9;
 | 
						|
// To avoid overswitching, we disable switching for a period of time after a
 | 
						|
// switch is done.
 | 
						|
const int kDefaultMinTimeBetweenSwitches = 1000;
 | 
						|
}
 | 
						|
 | 
						|
CurrentSpeakerMonitor::CurrentSpeakerMonitor(Call* call, BaseSession* session)
 | 
						|
    : started_(false),
 | 
						|
      call_(call),
 | 
						|
      session_(session),
 | 
						|
      current_speaker_ssrc_(0),
 | 
						|
      earliest_permitted_switch_time_(0),
 | 
						|
      min_time_between_switches_(kDefaultMinTimeBetweenSwitches) {
 | 
						|
}
 | 
						|
 | 
						|
CurrentSpeakerMonitor::~CurrentSpeakerMonitor() {
 | 
						|
  Stop();
 | 
						|
}
 | 
						|
 | 
						|
void CurrentSpeakerMonitor::Start() {
 | 
						|
  if (!started_) {
 | 
						|
    call_->SignalAudioMonitor.connect(
 | 
						|
        this, &CurrentSpeakerMonitor::OnAudioMonitor);
 | 
						|
    call_->SignalMediaStreamsUpdate.connect(
 | 
						|
        this, &CurrentSpeakerMonitor::OnMediaStreamsUpdate);
 | 
						|
 | 
						|
    started_ = true;
 | 
						|
  }
 | 
						|
}
 | 
						|
 | 
						|
void CurrentSpeakerMonitor::Stop() {
 | 
						|
  if (started_) {
 | 
						|
    call_->SignalAudioMonitor.disconnect(this);
 | 
						|
    call_->SignalMediaStreamsUpdate.disconnect(this);
 | 
						|
 | 
						|
    started_ = false;
 | 
						|
    ssrc_to_speaking_state_map_.clear();
 | 
						|
    current_speaker_ssrc_ = 0;
 | 
						|
    earliest_permitted_switch_time_ = 0;
 | 
						|
  }
 | 
						|
}
 | 
						|
 | 
						|
void CurrentSpeakerMonitor::set_min_time_between_switches(
 | 
						|
    uint32 min_time_between_switches) {
 | 
						|
  min_time_between_switches_ = min_time_between_switches;
 | 
						|
}
 | 
						|
 | 
						|
void CurrentSpeakerMonitor::OnAudioMonitor(Call* call, const AudioInfo& info) {
 | 
						|
  std::map<uint32, int> active_ssrc_to_level_map;
 | 
						|
  cricket::AudioInfo::StreamList::const_iterator stream_list_it;
 | 
						|
  for (stream_list_it = info.active_streams.begin();
 | 
						|
       stream_list_it != info.active_streams.end(); ++stream_list_it) {
 | 
						|
    uint32 ssrc = stream_list_it->first;
 | 
						|
    active_ssrc_to_level_map[ssrc] = stream_list_it->second;
 | 
						|
 | 
						|
    // It's possible we haven't yet added this source to our map.  If so,
 | 
						|
    // add it now with a "not speaking" state.
 | 
						|
    if (ssrc_to_speaking_state_map_.find(ssrc) ==
 | 
						|
        ssrc_to_speaking_state_map_.end()) {
 | 
						|
      ssrc_to_speaking_state_map_[ssrc] = SS_NOT_SPEAKING;
 | 
						|
    }
 | 
						|
  }
 | 
						|
 | 
						|
  int max_level = 0;
 | 
						|
  uint32 loudest_speaker_ssrc = 0;
 | 
						|
 | 
						|
  // Update the speaking states of all participants based on the new audio
 | 
						|
  // level information.  Also retain loudest speaker.
 | 
						|
  std::map<uint32, SpeakingState>::iterator state_it;
 | 
						|
  for (state_it = ssrc_to_speaking_state_map_.begin();
 | 
						|
       state_it != ssrc_to_speaking_state_map_.end(); ++state_it) {
 | 
						|
    bool is_previous_speaker = current_speaker_ssrc_ == state_it->first;
 | 
						|
 | 
						|
    // This uses a state machine in order to gradually identify
 | 
						|
    // members as having started or stopped speaking. Matches the
 | 
						|
    // algorithm used by the hangouts js code.
 | 
						|
 | 
						|
    std::map<uint32, int>::const_iterator level_it =
 | 
						|
        active_ssrc_to_level_map.find(state_it->first);
 | 
						|
    // Note that the stream map only contains streams with non-zero audio
 | 
						|
    // levels.
 | 
						|
    int level = (level_it != active_ssrc_to_level_map.end()) ?
 | 
						|
        level_it->second : 0;
 | 
						|
    switch (state_it->second) {
 | 
						|
      case SS_NOT_SPEAKING:
 | 
						|
        if (level > 0) {
 | 
						|
          // Reset level because we don't think they're really speaking.
 | 
						|
          level = 0;
 | 
						|
          state_it->second = SS_MIGHT_BE_SPEAKING;
 | 
						|
        } else {
 | 
						|
          // State unchanged.
 | 
						|
        }
 | 
						|
        break;
 | 
						|
      case SS_MIGHT_BE_SPEAKING:
 | 
						|
        if (level > 0) {
 | 
						|
          state_it->second = SS_SPEAKING;
 | 
						|
        } else {
 | 
						|
          state_it->second = SS_NOT_SPEAKING;
 | 
						|
        }
 | 
						|
        break;
 | 
						|
      case SS_SPEAKING:
 | 
						|
        if (level > 0) {
 | 
						|
          // State unchanged.
 | 
						|
        } else {
 | 
						|
          state_it->second = SS_WAS_SPEAKING_RECENTLY1;
 | 
						|
          if (is_previous_speaker) {
 | 
						|
            // Assume this is an inter-word silence and assign him the highest
 | 
						|
            // volume.
 | 
						|
            level = kMaxAudioLevel;
 | 
						|
          }
 | 
						|
        }
 | 
						|
        break;
 | 
						|
      case SS_WAS_SPEAKING_RECENTLY1:
 | 
						|
        if (level > 0) {
 | 
						|
          state_it->second = SS_SPEAKING;
 | 
						|
        } else {
 | 
						|
          state_it->second = SS_WAS_SPEAKING_RECENTLY2;
 | 
						|
          if (is_previous_speaker) {
 | 
						|
            // Assume this is an inter-word silence and assign him the highest
 | 
						|
            // volume.
 | 
						|
            level = kMaxAudioLevel;
 | 
						|
          }
 | 
						|
        }
 | 
						|
        break;
 | 
						|
      case SS_WAS_SPEAKING_RECENTLY2:
 | 
						|
        if (level > 0) {
 | 
						|
          state_it->second = SS_SPEAKING;
 | 
						|
        } else {
 | 
						|
          state_it->second = SS_NOT_SPEAKING;
 | 
						|
        }
 | 
						|
        break;
 | 
						|
    }
 | 
						|
 | 
						|
    if (level > max_level) {
 | 
						|
      loudest_speaker_ssrc = state_it->first;
 | 
						|
      max_level = level;
 | 
						|
    } else if (level > 0 && level == max_level && is_previous_speaker) {
 | 
						|
      // Favor continuity of loudest speakers if audio levels are equal.
 | 
						|
      loudest_speaker_ssrc = state_it->first;
 | 
						|
    }
 | 
						|
  }
 | 
						|
 | 
						|
  // We avoid over-switching by disabling switching for a period of time after
 | 
						|
  // a switch is done.
 | 
						|
  uint32 now = talk_base::Time();
 | 
						|
  if (earliest_permitted_switch_time_ <= now &&
 | 
						|
      current_speaker_ssrc_ != loudest_speaker_ssrc) {
 | 
						|
    current_speaker_ssrc_ = loudest_speaker_ssrc;
 | 
						|
    LOG(LS_INFO) << "Current speaker changed to " << current_speaker_ssrc_;
 | 
						|
    earliest_permitted_switch_time_ = now + min_time_between_switches_;
 | 
						|
    SignalUpdate(this, current_speaker_ssrc_);
 | 
						|
  }
 | 
						|
}
 | 
						|
 | 
						|
void CurrentSpeakerMonitor::OnMediaStreamsUpdate(Call* call,
 | 
						|
                                                 Session* session,
 | 
						|
                                                 const MediaStreams& added,
 | 
						|
                                                 const MediaStreams& removed) {
 | 
						|
  if (call == call_ && session == session_) {
 | 
						|
    // Update the speaking state map based on added and removed streams.
 | 
						|
    for (std::vector<cricket::StreamParams>::const_iterator
 | 
						|
           it = removed.video().begin(); it != removed.video().end(); ++it) {
 | 
						|
      ssrc_to_speaking_state_map_.erase(it->first_ssrc());
 | 
						|
    }
 | 
						|
 | 
						|
    for (std::vector<cricket::StreamParams>::const_iterator
 | 
						|
           it = added.video().begin(); it != added.video().end(); ++it) {
 | 
						|
      ssrc_to_speaking_state_map_[it->first_ssrc()] = SS_NOT_SPEAKING;
 | 
						|
    }
 | 
						|
  }
 | 
						|
}
 | 
						|
 | 
						|
}  // namespace cricket
 |