Bug 1576836 - Let audio elements end when a MediaStream becomes inaudible. r=jib

Depends on D43628

Differential Revision: https://phabricator.services.mozilla.com/D43629

--HG--
extra : moz-landing-system : lando

dom/html/HTMLMediaElement.cpp

@@ -4720,10 +4720,8 @@ class HTMLMediaElement::MediaStreamTrackListener
     mElement->NotifyMediaStreamTrackRemoved(aTrack);
   }
 
-  void NotifyActive() override {
-    if (!mElement) {
-      return;
-    }
+  void OnActive() {
+    MOZ_ASSERT(mElement);
 
     // mediacapture-main says:
     // Note that once ended equals true the HTMLVideoElement will not play media
@@ -4756,20 +4754,70 @@ class HTMLMediaElement::MediaStreamTrackListener
     mElement->DoLoad();
   }
 
-  void NotifyInactive() override {
+  void NotifyActive() override {
     if (!mElement) {
       return;
     }
+
+    if (!mElement->IsVideo()) {
+      // Audio elements use NotifyAudible().
+      return;
+    }
+
+    OnActive();
+  }
+
+  void NotifyAudible() override {
+    if (!mElement) {
+      return;
+    }
+
+    if (mElement->IsVideo()) {
+      // Video elements use NotifyActive().
+      return;
+    }
+
+    OnActive();
+  }
+
+  void OnInactive() {
+    MOZ_ASSERT(mElement);
+
     if (mElement->IsPlaybackEnded()) {
       return;
     }
     LOG(LogLevel::Debug, ("%p, mSrcStream %p became inactive", mElement.get(),
                           mElement->mSrcStream.get()));
-    MOZ_ASSERT(!mElement->mSrcStream->Active());
     mElement->PlaybackEnded();
     mElement->UpdateReadyStateInternal();
   }
 
+  void NotifyInactive() override {
+    if (!mElement) {
+      return;
+    }
+
+    if (!mElement->IsVideo()) {
+      // Audio elements use NotifyInaudible().
+      return;
+    }
+
+    OnInactive();
+  }
+
+  void NotifyInaudible() override {
+    if (!mElement) {
+      return;
+    }
+
+    if (mElement->IsVideo()) {
+      // Video elements use NotifyInactive().
+      return;
+    }
+
+    OnInactive();
+  }
+
  protected:
   const WeakPtr<HTMLMediaElement> mElement;
 };

dom/media/DOMMediaStream.cpp

@@ -57,6 +57,18 @@ static bool ContainsLiveTracks(
   return false;
 }
 
+static bool ContainsLiveAudioTracks(
+    const nsTArray<RefPtr<MediaStreamTrack>>& aTracks) {
+  for (const auto& track : aTracks) {
+    if (track->AsAudioStreamTrack() &&
+        track->ReadyState() == MediaStreamTrackState::Live) {
+      return true;
+    }
+  }
+
+  return false;
+}
+
 class DOMMediaStream::PlaybackTrackListener : public MediaStreamTrackConsumer {
  public:
   explicit PlaybackTrackListener(DOMMediaStream* aStream) : mStream(aStream) {}
@@ -420,6 +432,24 @@ void DOMMediaStream::NotifyInactive() {
   }
 }
 
+void DOMMediaStream::NotifyAudible() {
+  LOG(LogLevel::Info, ("DOMMediaStream %p NotifyAudible(). ", this));
+
+  MOZ_ASSERT(mAudible);
+  for (int32_t i = mTrackListeners.Length() - 1; i >= 0; --i) {
+    mTrackListeners[i]->NotifyAudible();
+  }
+}
+
+void DOMMediaStream::NotifyInaudible() {
+  LOG(LogLevel::Info, ("DOMMediaStream %p NotifyInaudible(). ", this));
+
+  MOZ_ASSERT(!mAudible);
+  for (int32_t i = mTrackListeners.Length() - 1; i >= 0; --i) {
+    mTrackListeners[i]->NotifyInaudible();
+  }
+}
+
 void DOMMediaStream::RegisterTrackListener(TrackListener* aListener) {
   MOZ_ASSERT(NS_IsMainThread());
 
@@ -454,14 +484,20 @@ void DOMMediaStream::NotifyTrackAdded(const RefPtr<MediaStreamTrack>& aTrack) {
     mTrackListeners[i]->NotifyTrackAdded(aTrack);
   }
 
-  if (mActive) {
-    return;
+  if (!mActive) {
+    // Check if we became active.
+    if (ContainsLiveTracks(mTracks)) {
+      mActive = true;
+      NotifyActive();
+    }
   }
 
-  // Check if we became active.
-  if (ContainsLiveTracks(mTracks)) {
-    mActive = true;
-    NotifyActive();
+  if (!mAudible) {
+    // Check if we became audible.
+    if (ContainsLiveAudioTracks(mTracks)) {
+      mAudible = true;
+      NotifyAudible();
+    }
   }
 }
 
@@ -491,6 +527,14 @@ void DOMMediaStream::NotifyTrackRemoved(
     return;
   }
 
+  if (mAudible) {
+    // Check if we became inaudible.
+    if (!ContainsLiveAudioTracks(mTracks)) {
+      mAudible = false;
+      NotifyInaudible();
+    }
+  }
+
   // Check if we became inactive.
   if (!ContainsLiveTracks(mTracks)) {
     mActive = false;

dom/media/DOMMediaStream.h

@@ -91,6 +91,16 @@ class DOMMediaStream : public DOMEventTargetHelper,
      * Called when the DOMMediaStream has become inactive.
      */
     virtual void NotifyInactive(){};
+
+    /**
+     * Called when the DOMMediaStream has become audible.
+     */
+    virtual void NotifyAudible(){};
+
+    /**
+     * Called when the DOMMediaStream has become inaudible.
+     */
+    virtual void NotifyInaudible(){};
   };
 
   explicit DOMMediaStream(nsPIDOMWindowInner* aWindow);
@@ -196,6 +206,12 @@ class DOMMediaStream : public DOMEventTargetHelper,
   // Dispatches NotifyInactive() to all registered track listeners.
   void NotifyInactive();
 
+  // Dispatches NotifyAudible() to all registered track listeners.
+  void NotifyAudible();
+
+  // Dispatches NotifyInaudible() to all registered track listeners.
+  void NotifyInaudible();
+
   // Dispatches NotifyTrackAdded() to all registered track listeners.
   void NotifyTrackAdded(const RefPtr<MediaStreamTrack>& aTrack);
 
@@ -227,6 +243,9 @@ class DOMMediaStream : public DOMEventTargetHelper,
   // True if this stream has live tracks.
   bool mActive;
 
+  // True if this stream has live audio tracks.
+  bool mAudible;
+
   // For compatibility with mozCaptureStream, we in some cases do not go
   // inactive until the MediaDecoder lets us. (Remove this in Bug 1302379)
   bool mFinishedOnInactive;