Revert of Rewrote UpdateToMix in the audio mixer.

webrtc/modules/audio_mixer/source/new_audio_conference_mixer_impl.cc

Index: webrtc/modules/audio_mixer/source/new_audio_conference_mixer_impl.cc
diff --git a/webrtc/modules/audio_mixer/source/new_audio_conference_mixer_impl.cc b/webrtc/modules/audio_mixer/source/new_audio_conference_mixer_impl.cc
index 861fb14b581da2ec03f9e4dbf089d1300ba57b2e..c1a49f221bcaf815158e1e58a5fc4fa66f1a89fb 100644
--- a/webrtc/modules/audio_mixer/source/new_audio_conference_mixer_impl.cc
+++ b/webrtc/modules/audio_mixer/source/new_audio_conference_mixer_impl.cc
@@ -11,7 +11,6 @@
 #include "webrtc/modules/audio_mixer/source/new_audio_conference_mixer_impl.h"
 
 #include <algorithm>
-#include <functional>
 
 #include "webrtc/modules/audio_conference_mixer/source/audio_frame_manipulator.h"
 #include "webrtc/modules/audio_mixer/include/audio_mixer_defines.h"
@@ -23,43 +22,15 @@
 namespace webrtc {
 namespace {
 
-class SourceFrame {
- public:
-  SourceFrame(MixerAudioSource* p,
-                      AudioFrame* a,
-                      bool m,
-                      bool was_mixed_before)
-      : audio_source_(p),
-        audio_frame_(a),
-        muted_(m),
-        was_mixed_before_(was_mixed_before) {
-    if (!muted_) {
-      energy_ = CalculateEnergy(*a);
-    }
-  }
-
-  // a.shouldMixBefore(b) is used to select mixer participants.
-  bool shouldMixBefore(const SourceFrame& other) const {
-    if (muted_ != other.muted_) {
-      return other.muted_;
-    }
-
-    auto our_activity = audio_frame_->vad_activity_;
-    auto other_activity = other.audio_frame_->vad_activity_;
-
-    if (our_activity != other_activity) {
-      return our_activity == AudioFrame::kVadActive;
-    }
-
-    return energy_ > other.energy_;
-  }
-
-  MixerAudioSource* audio_source_;
-  AudioFrame* audio_frame_;
-  bool muted_;
-  uint32_t energy_;
-  bool was_mixed_before_;
+struct AudioSourceWithFrame {
+  AudioSourceWithFrame(MixerAudioSource* p, AudioFrame* a, bool m)
+      : audio_source(p), audio_frame(a), muted(m) {}
+  MixerAudioSource* audio_source;
+  AudioFrame* audio_frame;
+  bool muted;
 };
+
+typedef std::list<AudioSourceWithFrame*> AudioSourceWithFrameList;
 
 // Mix |frame| into |mixed_frame|, with saturation protection and upmixing.
 // These effects are applied to |frame| itself prior to mixing. Assumes that
@@ -196,6 +167,7 @@
   size_t remainingAudioSourcesAllowedToMix = kMaximumAmountOfMixedAudioSources;
   RTC_DCHECK(thread_checker_.CalledOnValidThread());
   AudioFrameList mixList;
+  AudioFrameList rampOutList;
   AudioFrameList additionalFramesList;
   std::map<int, MixerAudioSource*> mixedAudioSourcesMap;
   {
@@ -242,17 +214,20 @@
       }
     }
 
-    mixList = UpdateToMix(remainingAudioSourcesAllowedToMix);
-    remainingAudioSourcesAllowedToMix -= mixList.size();
+    UpdateToMix(&mixList, &rampOutList, &mixedAudioSourcesMap,
+                &remainingAudioSourcesAllowedToMix);
+
     GetAdditionalAudio(&additionalFramesList);
+    UpdateMixedStatus(mixedAudioSourcesMap);
   }
 
   // TODO(aleloi): it might be better to decide the number of channels
   //                with an API instead of dynamically.
 
   // Find the max channels over all mixing lists.
-  const size_t num_mixed_channels =
-      std::max(MaxNumChannels(&mixList), MaxNumChannels(&additionalFramesList));
+  const size_t num_mixed_channels = std::max(
+      MaxNumChannels(&mixList), std::max(MaxNumChannels(&additionalFramesList),
+                                         MaxNumChannels(&rampOutList)));
 
   audio_frame_for_mixing->UpdateFrame(
       -1, _timeStamp, NULL, 0, _outputFrequency, AudioFrame::kNormalSpeech,
@@ -270,6 +245,7 @@
   {
     CriticalSectionScoped cs(_crit.get());
     MixAnonomouslyFromList(audio_frame_for_mixing, additionalFramesList);
+    MixAnonomouslyFromList(audio_frame_for_mixing, rampOutList);
 
     if (audio_frame_for_mixing->samples_per_channel_ == 0) {
       // Nothing was mixed, set the audio samples to silence.
@@ -280,6 +256,10 @@
       LimitMixedAudio(audio_frame_for_mixing);
     }
   }
+
+  ClearAudioFrameList(&mixList);
+  ClearAudioFrameList(&rampOutList);
+  ClearAudioFrameList(&additionalFramesList);
   return;
 }
 
@@ -446,62 +426,177 @@
   return highestFreq;
 }
 
-AudioFrameList NewAudioConferenceMixerImpl::UpdateToMix(
-    size_t maxAudioFrameCounter) const {
-  AudioFrameList result;
-  std::vector<SourceFrame> audioSourceMixingDataList;
-
-  // Get audio source audio and put it in the struct vector.
-  for (MixerAudioSource* audio_source : audio_source_list_) {
-    auto audio_frame_with_info = audio_source->GetAudioFrameWithMuted(
-        _id, static_cast<int>(_outputFrequency));
-
-    auto audio_frame_info = audio_frame_with_info.audio_frame_info;
-    AudioFrame* audio_source_audio_frame = audio_frame_with_info.audio_frame;
-
-    if (audio_frame_info == MixerAudioSource::AudioFrameInfo::kError) {
+void NewAudioConferenceMixerImpl::UpdateToMix(
+    AudioFrameList* mixList,
+    AudioFrameList* rampOutList,
+    std::map<int, MixerAudioSource*>* mixAudioSourceList,
+    size_t* maxAudioFrameCounter) const {
+  WEBRTC_TRACE(kTraceStream, kTraceAudioMixerServer, _id,
+               "UpdateToMix(mixList,rampOutList,mixAudioSourceList,%d)",
+               *maxAudioFrameCounter);
+  const size_t mixListStartSize = mixList->size();
+  AudioFrameList activeList;
+  // Struct needed by the passive lists to keep track of which AudioFrame
+  // belongs to which MixerAudioSource.
+  AudioSourceWithFrameList passiveWasNotMixedList;
+  AudioSourceWithFrameList passiveWasMixedList;
+  for (MixerAudioSourceList::const_iterator audio_source =
+           audio_source_list_.begin();
+       audio_source != audio_source_list_.end(); ++audio_source) {
+    // Stop keeping track of passive audioSources if there are already
+    // enough audio sources available (they wont be mixed anyway).
+    bool mustAddToPassiveList =
+        (*maxAudioFrameCounter >
+         (activeList.size() + passiveWasMixedList.size() +
+          passiveWasNotMixedList.size()));
+
+    bool wasMixed = false;
+    wasMixed = (*audio_source)->_mixHistory->WasMixed();
+
+    auto audio_frame_with_info =
+        (*audio_source)->GetAudioFrameWithMuted(_id, _outputFrequency);
+    auto ret = audio_frame_with_info.audio_frame_info;
+    AudioFrame* audio_frame = audio_frame_with_info.audio_frame;
+    if (ret == MixerAudioSource::AudioFrameInfo::kError) {
+      continue;
+    }
+    const bool muted = (ret == MixerAudioSource::AudioFrameInfo::kMuted);
+    if (audio_source_list_.size() != 1) {
+      // TODO(wu): Issue 3390, add support for multiple audio sources case.
+      audio_frame->ntp_time_ms_ = -1;
+    }
+
+    // TODO(aleloi): this assert triggers in some test cases where SRTP is
+    // used which prevents NetEQ from making a VAD. Temporarily disable this
+    // assert until the problem is fixed on a higher level.
+    // RTC_DCHECK_NE(audio_frame->vad_activity_, AudioFrame::kVadUnknown);
+    if (audio_frame->vad_activity_ == AudioFrame::kVadUnknown) {
       WEBRTC_TRACE(kTraceWarning, kTraceAudioMixerServer, _id,
-                   "failed to GetAudioFrameWithMuted() from participant");
-      continue;
-    }
-    audioSourceMixingDataList.emplace_back(
-        audio_source, audio_source_audio_frame,
-        audio_frame_info == MixerAudioSource::AudioFrameInfo::kMuted,
-        audio_source->_mixHistory->WasMixed());
-  }
-
-  // Sort frames by sorting function.
-  std::sort(audioSourceMixingDataList.begin(), audioSourceMixingDataList.end(),
-            std::mem_fn(&SourceFrame::shouldMixBefore));
-
-  // Go through list in order and put things in mixList.
-  for (SourceFrame& p : audioSourceMixingDataList) {
-    // Filter muted.
-    if (p.muted_) {
-      p.audio_source_->_mixHistory->SetIsMixed(false);
-      continue;
-    }
-
-    // Add frame to result vector for mixing.
-    bool is_mixed = false;
-    if (maxAudioFrameCounter > 0) {
-      --maxAudioFrameCounter;
-      if (!p.was_mixed_before_) {
-        RampIn(*p.audio_frame_);
+                   "invalid VAD state from audio source");
+    }
+
+    if (audio_frame->vad_activity_ == AudioFrame::kVadActive) {
+      if (!wasMixed && !muted) {
+        RampIn(*audio_frame);
       }
-      result.emplace_back(p.audio_frame_, false);
-      is_mixed = true;
-    }
-
-    // Ramp out unmuted.
-    if (p.was_mixed_before_ && !is_mixed) {
-      RampOut(*p.audio_frame_);
-      result.emplace_back(p.audio_frame_, false);
-    }
-
-    p.audio_source_->_mixHistory->SetIsMixed(is_mixed);
-  }
-  return result;
+
+      if (activeList.size() >= *maxAudioFrameCounter) {
+        // There are already more active audio sources than should be
+        // mixed. Only keep the ones with the highest energy.
+        AudioFrameList::iterator replaceItem;
+        uint32_t lowestEnergy = muted ? 0 : CalculateEnergy(*audio_frame);
+
+        bool found_replace_item = false;
+        for (AudioFrameList::iterator iter = activeList.begin();
+             iter != activeList.end(); ++iter) {
+          const uint32_t energy = muted ? 0 : CalculateEnergy(*iter->frame);
+          if (energy < lowestEnergy) {
+            replaceItem = iter;
+            lowestEnergy = energy;
+            found_replace_item = true;
+          }
+        }
+        if (found_replace_item) {
+          RTC_DCHECK(!muted);  // Cannot replace with a muted frame.
+          FrameAndMuteInfo replaceFrame = *replaceItem;
+
+          bool replaceWasMixed = false;
+          std::map<int, MixerAudioSource*>::const_iterator it =
+              mixAudioSourceList->find(replaceFrame.frame->id_);
+
+          // When a frame is pushed to |activeList| it is also pushed
+          // to mixAudioSourceList with the frame's id. This means
+          // that the Find call above should never fail.
+          RTC_DCHECK(it != mixAudioSourceList->end());
+          replaceWasMixed = it->second->_mixHistory->WasMixed();
+
+          mixAudioSourceList->erase(replaceFrame.frame->id_);
+          activeList.erase(replaceItem);
+
+          activeList.push_front(FrameAndMuteInfo(audio_frame, muted));
+          (*mixAudioSourceList)[audio_frame->id_] = *audio_source;
+          RTC_DCHECK_LE(mixAudioSourceList->size(),
+                        static_cast<size_t>(kMaximumAmountOfMixedAudioSources));
+
+          if (replaceWasMixed) {
+            if (!replaceFrame.muted) {
+              RampOut(*replaceFrame.frame);
+            }
+            rampOutList->push_back(replaceFrame);
+            RTC_DCHECK_LE(
+                rampOutList->size(),
+                static_cast<size_t>(kMaximumAmountOfMixedAudioSources));
+          }
+        } else {
+          if (wasMixed) {
+            if (!muted) {
+              RampOut(*audio_frame);
+            }
+            rampOutList->push_back(FrameAndMuteInfo(audio_frame, muted));
+            RTC_DCHECK_LE(
+                rampOutList->size(),
+                static_cast<size_t>(kMaximumAmountOfMixedAudioSources));
+          }
+        }
+      } else {
+        activeList.push_front(FrameAndMuteInfo(audio_frame, muted));
+        (*mixAudioSourceList)[audio_frame->id_] = *audio_source;
+        RTC_DCHECK_LE(mixAudioSourceList->size(),
+                      static_cast<size_t>(kMaximumAmountOfMixedAudioSources));
+      }
+    } else {
+      if (wasMixed) {
+        AudioSourceWithFrame* part_struct =
+            new AudioSourceWithFrame(*audio_source, audio_frame, muted);
+        passiveWasMixedList.push_back(part_struct);
+      } else if (mustAddToPassiveList) {
+        if (!muted) {
+          RampIn(*audio_frame);
+        }
+        AudioSourceWithFrame* part_struct =
+            new AudioSourceWithFrame(*audio_source, audio_frame, muted);
+        passiveWasNotMixedList.push_back(part_struct);
+      }
+    }
+  }
+  RTC_DCHECK_LE(activeList.size(), *maxAudioFrameCounter);
+  // At this point it is known which audio sources should be mixed. Transfer
+  // this information to this functions output parameters.
+  for (AudioFrameList::const_iterator iter = activeList.begin();
+       iter != activeList.end(); ++iter) {
+    mixList->push_back(*iter);
+  }
+  activeList.clear();
+  // Always mix a constant number of AudioFrames. If there aren't enough
+  // active audio sources mix passive ones. Starting with those that was mixed
+  // last iteration.
+  for (AudioSourceWithFrameList::const_iterator iter =
+           passiveWasMixedList.begin();
+       iter != passiveWasMixedList.end(); ++iter) {
+    if (mixList->size() < *maxAudioFrameCounter + mixListStartSize) {
+      mixList->push_back(
+          FrameAndMuteInfo((*iter)->audio_frame, (*iter)->muted));
+      (*mixAudioSourceList)[(*iter)->audio_frame->id_] = (*iter)->audio_source;
+      RTC_DCHECK_LE(mixAudioSourceList->size(),
+                    static_cast<size_t>(kMaximumAmountOfMixedAudioSources));
+    }
+    delete *iter;
+  }
+  // And finally the ones that have not been mixed for a while.
+  for (AudioSourceWithFrameList::const_iterator iter =
+           passiveWasNotMixedList.begin();
+       iter != passiveWasNotMixedList.end(); ++iter) {
+    if (mixList->size() < *maxAudioFrameCounter + mixListStartSize) {
+      mixList->push_back(
+          FrameAndMuteInfo((*iter)->audio_frame, (*iter)->muted));
+      (*mixAudioSourceList)[(*iter)->audio_frame->id_] = (*iter)->audio_source;
+      RTC_DCHECK_LE(mixAudioSourceList->size(),
+                    static_cast<size_t>(kMaximumAmountOfMixedAudioSources));
+    }
+    delete *iter;
+  }
+  RTC_DCHECK_GE(*maxAudioFrameCounter + mixListStartSize, mixList->size());
+  *maxAudioFrameCounter += mixListStartSize - mixList->size();
 }
 
 void NewAudioConferenceMixerImpl::GetAdditionalAudio(
@@ -538,6 +633,38 @@
   }
 }
 
+void NewAudioConferenceMixerImpl::UpdateMixedStatus(
+    const std::map<int, MixerAudioSource*>& mixedAudioSourcesMap) const {
+  WEBRTC_TRACE(kTraceStream, kTraceAudioMixerServer, _id,
+               "UpdateMixedStatus(mixedAudioSourcesMap)");
+  RTC_DCHECK_LE(mixedAudioSourcesMap.size(),
+                static_cast<size_t>(kMaximumAmountOfMixedAudioSources));
+
+  // Loop through all audio_sources. If they are in the mix map they
+  // were mixed.
+  for (MixerAudioSourceList::const_iterator audio_source =
+           audio_source_list_.begin();
+       audio_source != audio_source_list_.end(); ++audio_source) {
+    bool isMixed = false;
+    for (std::map<int, MixerAudioSource*>::const_iterator it =
+             mixedAudioSourcesMap.begin();
+         it != mixedAudioSourcesMap.end(); ++it) {
+      if (it->second == *audio_source) {
+        isMixed = true;
+        break;
+      }
+    }
+    (*audio_source)->_mixHistory->SetIsMixed(isMixed);
+  }
+}
+
+void NewAudioConferenceMixerImpl::ClearAudioFrameList(
+    AudioFrameList* audioFrameList) const {
+  WEBRTC_TRACE(kTraceStream, kTraceAudioMixerServer, _id,
+               "ClearAudioFrameList(audioFrameList)");
+  audioFrameList->clear();
+}
+
 bool NewAudioConferenceMixerImpl::IsAudioSourceInList(
     const MixerAudioSource& audio_source,
     const MixerAudioSourceList& audioSourceList) const {