Bug 1662805 - Replace instantaneous audibility decisions for MediaStream and regular playback with the AudibilityMonitor. r=pehrsons

Depends on D89634

Differential Revision: https://phabricator.services.mozilla.com/D89635

dom/media/MediaData.cpp

@@ -35,14 +35,6 @@ using media::TimeUnit;
 const char* AudioData::sTypeName = "audio";
 const char* VideoData::sTypeName = "video";
 
-bool IsDataLoudnessHearable(const AudioDataValue aData) {
-  // We can transfer the digital value to dBFS via following formula. According
-  // to American SMPTE standard, 0 dBu equals -20 dBFS. In theory 0 dBu is still
-  // hearable, so we choose a smaller value as our threshold. If the loudness
-  // is under this threshold, it might not be hearable.
-  return 20.0f * std::log10(AudioSampleToFloat(aData)) > -100;
-}
-
 AudioData::AudioData(int64_t aOffset, const media::TimeUnit& aTime,
                      AlignedAudioBuffer&& aData, uint32_t aChannels,
                      uint32_t aRate, uint32_t aChannelMap)
@@ -143,23 +135,6 @@ size_t AudioData::SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const {
   return size;
 }
 
-bool AudioData::IsAudible() const {
-  if (!mAudioData) {
-    return false;
-  }
-
-  const AudioDataValue* data = GetAdjustedData();
-
-  for (uint32_t frame = 0; frame < mFrames; ++frame) {
-    for (uint32_t channel = 0; channel < mChannels; ++channel) {
-      if (IsDataLoudnessHearable(data[frame * mChannels + channel])) {
-        return true;
-      }
-    }
-  }
-  return false;
-}
-
 AlignedAudioBuffer AudioData::MoveableData() {
   // Trim buffer according to trimming mask.
   mAudioData.PopFront(mDataOffset);

dom/media/MediaData.h

@@ -375,10 +375,6 @@ class AudioData : public MediaData {
   // If mAudioBuffer is null, creates it from mAudioData.
   void EnsureAudioBuffer();
 
-  // To check whether mAudioData has audible signal, it's used to distinguish
-  // the audiable data and silent data.
-  bool IsAudible() const;
-
   // Return true if the adjusted time is valid. Caller should handle error when
   // the result is invalid.
   bool AdjustForStartTime(const media::TimeUnit& aStartTime) override;

dom/media/mediasink/AudioSink.cpp

@@ -68,6 +68,7 @@ AudioSink::AudioSink(AbstractThread* aThread,
       mFramesParsed(0),
       mOutputRate(DecideAudioPlaybackSampleRate(aInfo)),
       mOutputChannels(DecideAudioPlaybackChannels(aInfo)),
+      mAudibilityMonitor(mOutputRate, 2.0),
       mAudioQueue(aAudioQueue)
   { }
 
@@ -316,7 +317,9 @@ void AudioSink::Errored() {
 void AudioSink::CheckIsAudible(const AudioData* aData) {
   MOZ_ASSERT(aData);
 
-  bool isAudible = aData->IsAudible();
+  mAudibilityMonitor.ProcessAudioData(aData);
+  bool isAudible = mAudibilityMonitor.RecentlyAudible();
+
   if (isAudible != mIsAudioDataAudible) {
     mIsAudioDataAudible = isAudible;
     mAudibleEvent.Notify(mIsAudioDataAudible);

dom/media/mediasink/AudioSink.h

@@ -7,6 +7,7 @@
 #define AudioSink_h__
 
 #include "AudioStream.h"
+#include "AudibilityMonitor.h"
 #include "MediaEventSource.h"
 #include "MediaInfo.h"
 #include "MediaQueue.h"
@@ -161,10 +162,8 @@ class AudioSink : private AudioStream::DataSource {
   // Never modifed after construction.
   uint32_t mOutputRate;
   uint32_t mOutputChannels;
-
-  // True when audio is producing audible sound, false when audio is silent.
+  AudibilityMonitor mAudibilityMonitor;
   bool mIsAudioDataAudible;
-
   MediaEventProducer<bool> mAudibleEvent;
 
   MediaQueue<AudioData>& mAudioQueue;

dom/media/mediasink/DecodedStream.cpp

@@ -420,6 +420,7 @@ nsresult DecodedStream::Start(const TimeUnit& aStartTime,
   mPlaying = true;
   mPrincipalHandle.Connect(mCanonicalOutputPrincipal);
   mWatchManager.Watch(mPlaying, &DecodedStream::PlayingChanged);
+  mAudibilityMonitor.emplace(AudibilityMonitor(mInfo.mAudio.mRate, 2.0f));
   ConnectListener();
 
   class R : public Runnable {
@@ -517,6 +518,7 @@ void DecodedStream::Stop() {
 
   mPrincipalHandle.DisconnectIfConnected();
   mWatchManager.Unwatch(mPlaying, &DecodedStream::PlayingChanged);
+  mAudibilityMonitor.reset();
 }
 
 bool DecodedStream::IsStarted() const {
@@ -674,7 +676,9 @@ void DecodedStream::SendAudio(double aVolume,
 void DecodedStream::CheckIsDataAudible(const AudioData* aData) {
   MOZ_ASSERT(aData);
 
-  bool isAudible = aData->IsAudible();
+  mAudibilityMonitor->ProcessAudioData(aData);
+  bool isAudible = mAudibilityMonitor->RecentlyAudible();
+
   if (isAudible != mIsAudioDataAudible) {
     mIsAudioDataAudible = isAudible;
     mAudibleEvent.Notify(mIsAudioDataAudible);

dom/media/mediasink/DecodedStream.h

@@ -111,6 +111,7 @@ class DecodedStream : public MediaSink {
   MediaInfo mInfo;
   // True when stream is producing audible sound, false when stream is silent.
   bool mIsAudioDataAudible = false;
+  Maybe<AudibilityMonitor> mAudibilityMonitor;
   MediaEventProducer<bool> mAudibleEvent;
 
   MediaQueue<AudioData>& mAudioQueue;