Revert of Removing webrtc::AudioFrame::energy_. (patchset #2 id:20001 of https://codereview.webrtc.org/1589953002/ )

Reason for revert:
The change breaks google3 tests for buzz/mediaengines/sae/audio_mixer.

Original issue's description:
> Remove webrtc::AudioFrame::energy_.
>
> BUG=webrtc:3315
>
> Committed: https://crrev.com/bacae81a1d91ae7b2a4bde37a66ab70513449989
> Cr-Commit-Position: refs/heads/master@{#11372}

TBR=kjellander@webrtc.org,henrik.lundin@webrtc.org,tommi@webrtc.org,minyue@webrtc.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=webrtc:3315

Review URL: https://codereview.webrtc.org/1634143002

Cr-Commit-Position: refs/heads/master@{#11377}

webrtc/modules/audio_conference_mixer/source/audio_conference_mixer_impl.cc

@@ -583,16 +583,17 @@ void AudioConferenceMixerImpl::UpdateToMix(
                 // There are already more active participants than should be
                 // mixed. Only keep the ones with the highest energy.
                 AudioFrameList::iterator replaceItem;
-                uint32_t lowestEnergy = CalculateEnergy(*audioFrame);
+                CalculateEnergy(*audioFrame);
+                uint32_t lowestEnergy = audioFrame->energy_;
 
                 bool found_replace_item = false;
                 for (AudioFrameList::iterator iter = activeList.begin();
                      iter != activeList.end();
                      ++iter) {
-                    const uint32_t energy = CalculateEnergy(**iter);
-                    if(energy < lowestEnergy) {
+                    CalculateEnergy(**iter);
+                    if((*iter)->energy_ < lowestEnergy) {
                         replaceItem = iter;
-                        lowestEnergy = energy;
+                        lowestEnergy = (*iter)->energy_;
                         found_replace_item = true;
                     }
                 }
@@ -782,6 +783,18 @@ void AudioConferenceMixerImpl::ClearAudioFrameList(
     audioFrameList->clear();
 }
 
+void AudioConferenceMixerImpl::UpdateVADPositiveParticipants(
+    AudioFrameList* mixList) const {
+    WEBRTC_TRACE(kTraceStream, kTraceAudioMixerServer, _id,
+                 "UpdateVADPositiveParticipants(mixList)");
+
+    for (AudioFrameList::const_iterator iter = mixList->begin();
+         iter != mixList->end();
+         ++iter) {
+        CalculateEnergy(**iter);
+    }
+}
+
 bool AudioConferenceMixerImpl::IsParticipantInList(
     const MixerParticipant& participant,
     const MixerParticipantList& participantList) const {

webrtc/modules/audio_conference_mixer/source/audio_conference_mixer_impl.h

@@ -116,6 +116,10 @@ private:
     // Clears audioFrameList and reclaims all memory associated with it.
     void ClearAudioFrameList(AudioFrameList* audioFrameList) const;
 
+    // Update the list of MixerParticipants who have a positive VAD. mixList
+    // should be a list of AudioFrames
+    void UpdateVADPositiveParticipants(AudioFrameList* mixList) const;
+
     // This function returns true if it finds the MixerParticipant in the
     // specified list of MixerParticipants.
     bool IsParticipantInList(const MixerParticipant& participant,

webrtc/modules/audio_conference_mixer/source/audio_frame_manipulator.cc

@@ -39,16 +39,16 @@ const size_t rampSize = sizeof(rampArray)/sizeof(rampArray[0]);
 }  // namespace
 
 namespace webrtc {
-uint32_t CalculateEnergy(const AudioFrame& audioFrame)
+void CalculateEnergy(AudioFrame& audioFrame)
 {
-    uint32_t energy = 0;
+    audioFrame.energy_ = 0;
     for(size_t position = 0; position < audioFrame.samples_per_channel_;
         position++)
     {
         // TODO(andrew): this can easily overflow.
-        energy += audioFrame.data_[position] * audioFrame.data_[position];
+        audioFrame.energy_ += audioFrame.data_[position] *
+                              audioFrame.data_[position];
     }
-    return energy;
 }
 
 void RampIn(AudioFrame& audioFrame)

webrtc/modules/audio_conference_mixer/source/audio_frame_manipulator.h

@@ -11,13 +11,11 @@
 #ifndef WEBRTC_MODULES_AUDIO_CONFERENCE_MIXER_SOURCE_AUDIO_FRAME_MANIPULATOR_H_
 #define WEBRTC_MODULES_AUDIO_CONFERENCE_MIXER_SOURCE_AUDIO_FRAME_MANIPULATOR_H_
 
-#include "webrtc/typedefs.h"
-
 namespace webrtc {
 class AudioFrame;
 
 // Updates the audioFrame's energy (based on its samples).
-uint32_t CalculateEnergy(const AudioFrame& audioFrame);
+void CalculateEnergy(AudioFrame& audioFrame);
 
 // Apply linear step function that ramps in/out the audio samples in audioFrame
 void RampIn(AudioFrame& audioFrame);

webrtc/modules/include/module_common_types.h

@@ -508,7 +508,7 @@ class AudioFrame {
   void UpdateFrame(int id, uint32_t timestamp, const int16_t* data,
                    size_t samples_per_channel, int sample_rate_hz,
                    SpeechType speech_type, VADActivity vad_activity,
-                   size_t num_channels = 1);
+                   size_t num_channels = 1, uint32_t energy = -1);
 
   AudioFrame& Append(const AudioFrame& rhs);
 
@@ -535,6 +535,11 @@ class AudioFrame {
   size_t num_channels_;
   SpeechType speech_type_;
   VADActivity vad_activity_;
+  // Note that there is no guarantee that |energy_| is correct. Any user of this
+  // member must verify that the value is correct.
+  // TODO(henrike) Remove |energy_|.
+  // See https://code.google.com/p/webrtc/issues/detail?id=3315.
+  uint32_t energy_;
   bool interleaved_;
 
  private:
@@ -558,6 +563,7 @@ inline void AudioFrame::Reset() {
   num_channels_ = 0;
   speech_type_ = kUndefined;
   vad_activity_ = kVadUnknown;
+  energy_ = 0xffffffff;
   interleaved_ = true;
 }
 
@@ -568,7 +574,8 @@ inline void AudioFrame::UpdateFrame(int id,
                                     int sample_rate_hz,
                                     SpeechType speech_type,
                                     VADActivity vad_activity,
-                                    size_t num_channels) {
+                                    size_t num_channels,
+                                    uint32_t energy) {
   id_ = id;
   timestamp_ = timestamp;
   samples_per_channel_ = samples_per_channel;
@@ -576,6 +583,7 @@ inline void AudioFrame::UpdateFrame(int id,
   speech_type_ = speech_type;
   vad_activity_ = vad_activity;
   num_channels_ = num_channels;
+  energy_ = energy;
 
   const size_t length = samples_per_channel * num_channels;
   assert(length <= kMaxDataSizeSamples);
@@ -598,6 +606,7 @@ inline void AudioFrame::CopyFrom(const AudioFrame& src) {
   speech_type_ = src.speech_type_;
   vad_activity_ = src.vad_activity_;
   num_channels_ = src.num_channels_;
+  energy_ = src.energy_;
   interleaved_ = src.interleaved_;
 
   const size_t length = samples_per_channel_ * num_channels_;
@@ -692,6 +701,7 @@ inline AudioFrame& AudioFrame::operator+=(const AudioFrame& rhs) {
       data_[i] = ClampToInt16(wrap_guard);
     }
   }
+  energy_ = 0xffffffff;
   return *this;
 }
 
@@ -715,6 +725,7 @@ inline AudioFrame& AudioFrame::operator-=(const AudioFrame& rhs) {
         static_cast<int32_t>(data_[i]) - static_cast<int32_t>(rhs.data_[i]);
     data_[i] = ClampToInt16(wrap_guard);
   }
+  energy_ = 0xffffffff;
   return *this;
 }