pc/currentspeakermonitor.cc - src/webrtc - Git at Google

 /*
  *  Copyright 2011 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */

 #include "webrtc/pc/currentspeakermonitor.h"

 #include <vector>

 #include "webrtc/media/base/streamparams.h"
 #include "webrtc/pc/audiomonitor.h"
 #include "webrtc/rtc_base/logging.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(
     AudioSourceContext* audio_source_context)
     : started_(false),
       audio_source_context_(audio_source_context),
       current_speaker_ssrc_(0),
       earliest_permitted_switch_time_(0),
       min_time_between_switches_(kDefaultMinTimeBetweenSwitches) {}

 CurrentSpeakerMonitor::~CurrentSpeakerMonitor() {
   Stop();
 }

 void CurrentSpeakerMonitor::Start() {
   if (!started_) {
     audio_source_context_->SignalAudioMonitor.connect(
         this, &CurrentSpeakerMonitor::OnAudioMonitor);
     audio_source_context_->SignalMediaStreamsUpdate.connect(
         this, &CurrentSpeakerMonitor::OnMediaStreamsUpdate);
     audio_source_context_->SignalMediaStreamsReset.connect(
         this, &CurrentSpeakerMonitor::OnMediaStreamsReset);

     started_ = true;
   }
 }

 void CurrentSpeakerMonitor::Stop() {
   if (started_) {
     audio_source_context_->SignalAudioMonitor.disconnect(this);
     audio_source_context_->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(
     int min_time_between_switches) {
   min_time_between_switches_ = min_time_between_switches;
 }

 void CurrentSpeakerMonitor::OnAudioMonitor(
     AudioSourceContext* audio_source_context, const AudioInfo& info) {
   std::map<uint32_t, 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_t 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_t 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_t, 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_t, 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.
   int64_t now = rtc::TimeMillis();
   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(
     AudioSourceContext* audio_source_context,
     const MediaStreams& added,
     const MediaStreams& removed) {
   if (audio_source_context == audio_source_context_) {
     // Update the speaking state map based on added and removed streams.
     for (std::vector<cricket::StreamParams>::const_iterator
            it = removed.audio().begin(); it != removed.audio().end(); ++it) {
       ssrc_to_speaking_state_map_.erase(it->first_ssrc());
     }

     for (std::vector<cricket::StreamParams>::const_iterator
            it = added.audio().begin(); it != added.audio().end(); ++it) {
       ssrc_to_speaking_state_map_[it->first_ssrc()] = SS_NOT_SPEAKING;
     }
   }
 }

 void CurrentSpeakerMonitor::OnMediaStreamsReset(
     AudioSourceContext* audio_source_context) {
   if (audio_source_context == audio_source_context_) {
     ssrc_to_speaking_state_map_.clear();
   }
 }

 }  // namespace cricket
	/*
	* Copyright 2011 The WebRTC project authors. All Rights Reserved.
	*
	* Use of this source code is governed by a BSD-style license
	* that can be found in the LICENSE file in the root of the source
	* tree. An additional intellectual property rights grant can be found
	* in the file PATENTS. All contributing project authors may
	* be found in the AUTHORS file in the root of the source tree.
	*/

	#include "webrtc/pc/currentspeakermonitor.h"

	#include <vector>

	#include "webrtc/media/base/streamparams.h"
	#include "webrtc/pc/audiomonitor.h"
	#include "webrtc/rtc_base/logging.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(
	AudioSourceContext* audio_source_context)
	: started_(false),
	audio_source_context_(audio_source_context),
	current_speaker_ssrc_(0),
	earliest_permitted_switch_time_(0),
	min_time_between_switches_(kDefaultMinTimeBetweenSwitches) {}

	CurrentSpeakerMonitor::~CurrentSpeakerMonitor() {
	Stop();
	}

	void CurrentSpeakerMonitor::Start() {
	if (!started_) {
	audio_source_context_->SignalAudioMonitor.connect(
	this, &CurrentSpeakerMonitor::OnAudioMonitor);
	audio_source_context_->SignalMediaStreamsUpdate.connect(
	this, &CurrentSpeakerMonitor::OnMediaStreamsUpdate);
	audio_source_context_->SignalMediaStreamsReset.connect(
	this, &CurrentSpeakerMonitor::OnMediaStreamsReset);

	started_ = true;
	}
	}

	void CurrentSpeakerMonitor::Stop() {
	if (started_) {
	audio_source_context_->SignalAudioMonitor.disconnect(this);
	audio_source_context_->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(
	int min_time_between_switches) {
	min_time_between_switches_ = min_time_between_switches;
	}

	void CurrentSpeakerMonitor::OnAudioMonitor(
	AudioSourceContext* audio_source_context, const AudioInfo& info) {
	std::map<uint32_t, 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_t 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_t 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_t, 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_t, 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.
	int64_t now = rtc::TimeMillis();
	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(
	AudioSourceContext* audio_source_context,
	const MediaStreams& added,
	const MediaStreams& removed) {
	if (audio_source_context == audio_source_context_) {
	// Update the speaking state map based on added and removed streams.
	for (std::vector<cricket::StreamParams>::const_iterator
	it = removed.audio().begin(); it != removed.audio().end(); ++it) {
	ssrc_to_speaking_state_map_.erase(it->first_ssrc());
	}

	for (std::vector<cricket::StreamParams>::const_iterator
	it = added.audio().begin(); it != added.audio().end(); ++it) {
	ssrc_to_speaking_state_map_[it->first_ssrc()] = SS_NOT_SPEAKING;
	}
	}
	}

	void CurrentSpeakerMonitor::OnMediaStreamsReset(
	AudioSourceContext* audio_source_context) {
	if (audio_source_context == audio_source_context_) {
	ssrc_to_speaking_state_map_.clear();
	}
	}

	} // namespace cricket