Bug 1156472 - Part 6 - Connect HTMLMediaElement and AudioContext to the capture stream when capturing is needed. r=roc

dom/html/HTMLMediaElement.cpp

@@ -2030,6 +2030,7 @@ HTMLMediaElement::HTMLMediaElement(already_AddRefed<mozilla::dom::NodeInfo>& aNo
     mAllowCasting(false),
     mIsCasting(false),
     mAudioCaptured(false),
+    mAudioCapturedByWindow(false),
     mPlayingBeforeSeek(false),
     mPlayingThroughTheAudioChannelBeforeSeek(false),
     mPausedForInactiveDocumentOrChannel(false),
@@ -2097,6 +2098,11 @@ HTMLMediaElement::~HTMLMediaElement()
     EndSrcMediaStreamPlayback();
   }
 
+  if (mCaptureStreamPort) {
+    mCaptureStreamPort->Destroy();
+    mCaptureStreamPort = nullptr;
+  }
+
   NS_ASSERTION(MediaElementTableCount(this, mLoadingSrc) == 0,
     "Destroyed media element should no longer be in element table");
 
@@ -4475,8 +4481,7 @@ void HTMLMediaElement::UpdateAudioChannelPlayingState()
      (!mPaused &&
       (HasAttr(kNameSpaceID_None, nsGkAtoms::loop) ||
        (mReadyState >= nsIDOMHTMLMediaElement::HAVE_CURRENT_DATA &&
-        !IsPlaybackEnded() &&
+        !IsPlaybackEnded()) ||
-        (!mSrcStream || HasAudio())) ||
        mPlayingThroughTheAudioChannelBeforeSeek));
   if (playingThroughTheAudioChannel != mPlayingThroughTheAudioChannel) {
     mPlayingThroughTheAudioChannel = playingThroughTheAudioChannel;
@@ -4681,9 +4686,31 @@ HTMLMediaElement::GetTopLevelPrincipal()
 NS_IMETHODIMP HTMLMediaElement::WindowAudioCaptureChanged()
 {
    MOZ_ASSERT(mAudioChannelAgent);
-  DebugOnly<bool> captured = OwnerDoc()->GetInnerWindow()->GetAudioCaptured();
 
-  // Something is going to happen here!!
+  if (!OwnerDoc()->GetInnerWindow()) {
+    return NS_OK;
+  }
+  bool captured = OwnerDoc()->GetInnerWindow()->GetAudioCaptured();
+
+  if (captured != mAudioCapturedByWindow) {
+    if (captured) {
+      mAudioCapturedByWindow = true;
+      nsCOMPtr<nsPIDOMWindow> window =
+        do_QueryInterface(OwnerDoc()->GetParentObject());
+      uint64_t id = window->WindowID();
+      MediaStreamGraph* msg = MediaStreamGraph::GetInstance();
+
+      if (!mPlaybackStream) {
+        nsRefPtr<DOMMediaStream> stream = CaptureStreamInternal(false, msg);
+        mCaptureStreamPort = msg->ConnectToCaptureStream(id, stream->GetStream());
+      } else {
+        mCaptureStreamPort = msg->ConnectToCaptureStream(id, mPlaybackStream->GetStream());
+      }
+    } else {
+      // TODO: uncapture
+    }
+  }
+
    return NS_OK;
 }
 

dom/html/HTMLMediaElement.h

@@ -1074,6 +1074,9 @@ protected:
   // Holds a reference to a MediaInputPort connecting mSrcStream to mPlaybackStream.
   nsRefPtr<MediaInputPort> mPlaybackStreamInputPort;
 
+  // Holds a reference to the stream connecting this stream to the capture sink.
+  nsRefPtr<MediaInputPort> mCaptureStreamPort;
+
   // Holds a reference to a stream with mSrcStream as input but intended for
   // playback. Used so we don't block playback of other video elements
   // playing the same mSrcStream.
@@ -1283,6 +1286,9 @@ protected:
   // True if the sound is being captured.
   bool mAudioCaptured;
 
+  // True if the sound is being captured by the window.
+  bool mAudioCapturedByWindow;
+
   // If TRUE then the media element was actively playing before the currently
   // in progress seeking. If FALSE then the media element is either not seeking
   // or was not actively playing before the current seek. Used to decide whether

dom/media/webaudio/AudioDestinationNode.cpp

@@ -313,12 +313,9 @@ AudioDestinationNode::AudioDestinationNode(AudioContext* aContext,
                                            bool aIsOffline,
                                            AudioChannel aChannel,
                                            uint32_t aNumberOfChannels,
-                                           uint32_t aLength,
+                                           uint32_t aLength, float aSampleRate)
-                                           float aSampleRate)
+  : AudioNode(aContext, aIsOffline ? aNumberOfChannels : 2,
-  : AudioNode(aContext,
+              ChannelCountMode::Explicit, ChannelInterpretation::Speakers)
-              aIsOffline ? aNumberOfChannels : 2,
-              ChannelCountMode::Explicit,
-              ChannelInterpretation::Speakers)
   , mFramesToProduce(aLength)
   , mAudioChannel(AudioChannel::Normal)
   , mIsOffline(aIsOffline)
@@ -326,6 +323,7 @@ AudioDestinationNode::AudioDestinationNode(AudioContext* aContext,
   , mExtraCurrentTime(0)
   , mExtraCurrentTimeSinceLastStartedBlocking(0)
   , mExtraCurrentTimeUpdatedSinceLastStableState(false)
+  , mCaptured(false)
 {
   bool startWithAudioDriver = true;
   MediaStreamGraph* graph = aIsOffline ?
@@ -510,13 +508,25 @@ AudioDestinationNode::WindowAudioCaptureChanged()
 {
   MOZ_ASSERT(mAudioChannelAgent);
 
-  if (!mStream) {
+  if (!mStream || Context()->IsOffline()) {
     return NS_OK;
   }
 
-  DebugOnly<bool> captured = GetOwner()->GetAudioCaptured();
+  bool captured = GetOwner()->GetAudioCaptured();
+
+  if (captured != mCaptured) {
+    if (captured) {
+      nsCOMPtr<nsPIDOMWindow> window = Context()->GetParentObject();
+      uint64_t id = window->WindowID();
+      mCaptureStreamPort =
+        mStream->Graph()->ConnectToCaptureStream(id, mStream);
+    } else {
+      mCaptureStreamPort->Disconnect();
+      mCaptureStreamPort->Destroy();
+    }
+    mCaptured = captured;
+  }
 
-  // XXXtodopadenot actually capture
   return NS_OK;
 }
 
@@ -699,6 +709,7 @@ AudioDestinationNode::InputMuted(bool aMuted)
     return;
   }
 
+  WindowAudioCaptureChanged();
   WindowVolumeChanged(volume, muted);
 }
 

dom/media/webaudio/AudioDestinationNode.h

@@ -99,6 +99,7 @@ private:
   uint32_t mFramesToProduce;
 
   nsCOMPtr<nsIAudioChannelAgent> mAudioChannelAgent;
+  nsRefPtr<MediaInputPort> mCaptureStreamPort;
 
   nsRefPtr<Promise> mOfflineRenderingPromise;
 
@@ -111,6 +112,7 @@ private:
   double mExtraCurrentTime;
   double mExtraCurrentTimeSinceLastStartedBlocking;
   bool mExtraCurrentTimeUpdatedSinceLastStableState;
+  bool mCaptured;
 };
 
 } // namespace dom