From f7bb3fd5bd5332e983e241b6da4644ec1f360c2e Mon Sep 17 00:00:00 2001
From: Paul Adenot <paul@paul.cx>
Date: Fri, 24 Jul 2015 14:28:17 +0200
Subject: [PATCH] Bug 1156472 - Part 7 - Allow to un-capture an
 HTMLMediaElement.  r=pehrsons,jwwang

---
 dom/html/HTMLMediaElement.cpp          | 18 +++++++++++++++-
 dom/media/DecodedStream.cpp            |  8 +++++++
 dom/media/DecodedStream.h              |  1 +
 dom/media/MediaDecoder.cpp             |  7 +++++++
 dom/media/MediaDecoder.h               |  2 ++
 dom/media/MediaDecoderStateMachine.cpp | 29 ++++++++++++++++++++++++++
 dom/media/MediaDecoderStateMachine.h   |  3 +++
 7 files changed, 67 insertions(+), 1 deletion(-)

diff --git a/dom/html/HTMLMediaElement.cpp b/dom/html/HTMLMediaElement.cpp
index 790103de8c1d..aa5738059be0 100644
--- a/dom/html/HTMLMediaElement.cpp
+++ b/dom/html/HTMLMediaElement.cpp
@@ -4708,7 +4708,23 @@ NS_IMETHODIMP HTMLMediaElement::WindowAudioCaptureChanged()
         mCaptureStreamPort = msg->ConnectToCaptureStream(id, mPlaybackStream->GetStream());
       }
     } else {
-      // TODO: uncapture
+      mAudioCapturedByWindow = false;
+      if (mDecoder) {
+        ProcessedMediaStream* ps =
+          mCaptureStreamPort->GetSource()->AsProcessedStream();
+        MOZ_ASSERT(ps);
+
+        for (uint32_t i = 0; i < mOutputStreams.Length(); i++) {
+          if (mOutputStreams[i].mStream->GetStream() == ps) {
+            mOutputStreams.RemoveElementAt(i);
+            break;
+          }
+        }
+
+        mDecoder->RemoveOutputStream(ps);
+      }
+      mCaptureStreamPort->Destroy();
+      mCaptureStreamPort = nullptr;
     }
   }
 
diff --git a/dom/media/DecodedStream.cpp b/dom/media/DecodedStream.cpp
index dcc950228f72..913f68203e21 100644
--- a/dom/media/DecodedStream.cpp
+++ b/dom/media/DecodedStream.cpp
@@ -289,6 +289,14 @@ DecodedStream::OutputStreams()
   return mOutputStreams;
 }
 
+bool
+DecodedStream::HasConsumers() const
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  ReentrantMonitorAutoEnter mon(GetReentrantMonitor());
+  return mOutputStreams.IsEmpty();
+}
+
 ReentrantMonitor&
 DecodedStream::GetReentrantMonitor() const
 {
diff --git a/dom/media/DecodedStream.h b/dom/media/DecodedStream.h
index 8b25b95c9f7d..ebad8330c865 100644
--- a/dom/media/DecodedStream.h
+++ b/dom/media/DecodedStream.h
@@ -114,6 +114,7 @@ public:
   int64_t AudioEndTime() const;
   int64_t GetPosition() const;
   bool IsFinished() const;
+  bool HasConsumers() const;
 
   // Return true if stream is finished.
   bool SendData(double aVolume, bool aIsSameOrigin);
diff --git a/dom/media/MediaDecoder.cpp b/dom/media/MediaDecoder.cpp
index 59f7e5fcc59b..3f0cdadc6a19 100644
--- a/dom/media/MediaDecoder.cpp
+++ b/dom/media/MediaDecoder.cpp
@@ -326,6 +326,13 @@ void MediaDecoder::AddOutputStream(ProcessedMediaStream* aStream,
   mDecoderStateMachine->AddOutputStream(aStream, aFinishWhenEnded);
 }
 
+void MediaDecoder::RemoveOutputStream(MediaStream* aStream)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(mDecoderStateMachine, "Must be called after Load().");
+  mDecoderStateMachine->RemoveOutputStream(aStream);
+}
+
 double MediaDecoder::GetDuration()
 {
   MOZ_ASSERT(NS_IsMainThread());
diff --git a/dom/media/MediaDecoder.h b/dom/media/MediaDecoder.h
index c2a01bb07465..d216bf9c7666 100644
--- a/dom/media/MediaDecoder.h
+++ b/dom/media/MediaDecoder.h
@@ -399,6 +399,8 @@ public:
   // The stream is initially blocked. The decoder is responsible for unblocking
   // it while it is playing back.
   virtual void AddOutputStream(ProcessedMediaStream* aStream, bool aFinishWhenEnded);
+  // Remove an output stream added with AddOutputStream.
+  virtual void RemoveOutputStream(MediaStream* aStream);
 
   // Return the duration of the video in seconds.
   virtual double GetDuration();
diff --git a/dom/media/MediaDecoderStateMachine.cpp b/dom/media/MediaDecoderStateMachine.cpp
index 08929dd14976..ac546d835cf4 100644
--- a/dom/media/MediaDecoderStateMachine.cpp
+++ b/dom/media/MediaDecoderStateMachine.cpp
@@ -3140,6 +3140,25 @@ void MediaDecoderStateMachine::DispatchAudioCaptured()
   OwnerThread()->Dispatch(r.forget());
 }
 
+void MediaDecoderStateMachine::DispatchAudioUncaptured()
+{
+  nsRefPtr<MediaDecoderStateMachine> self = this;
+  nsCOMPtr<nsIRunnable> r = NS_NewRunnableFunction([self] () -> void
+  {
+    MOZ_ASSERT(self->OnTaskQueue());
+    ReentrantMonitorAutoEnter mon(self->mDecoder->GetReentrantMonitor());
+    if (self->mAudioCaptured) {
+      // Start again the audio sink
+      self->mAudioCaptured = false;
+      if (self->IsPlaying()) {
+        self->StartAudioThread();
+      }
+      self->ScheduleStateMachine();
+    }
+  });
+  OwnerThread()->Dispatch(r.forget());
+}
+
 void MediaDecoderStateMachine::AddOutputStream(ProcessedMediaStream* aStream,
                                                bool aFinishWhenEnded)
 {
@@ -3149,6 +3168,16 @@ void MediaDecoderStateMachine::AddOutputStream(ProcessedMediaStream* aStream,
   DispatchAudioCaptured();
 }
 
+void MediaDecoderStateMachine::RemoveOutputStream(MediaStream* aStream)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  DECODER_LOG("RemoveOutputStream=%p!", aStream);
+  mDecodedStream->Remove(aStream);
+  if (!mDecodedStream->HasConsumers()) {
+    DispatchAudioUncaptured();
+  }
+}
+
 } // namespace mozilla
 
 // avoid redefined macro in unified build
diff --git a/dom/media/MediaDecoderStateMachine.h b/dom/media/MediaDecoderStateMachine.h
index ac5bc525ad2e..f6d5cfa98015 100644
--- a/dom/media/MediaDecoderStateMachine.h
+++ b/dom/media/MediaDecoderStateMachine.h
@@ -148,6 +148,8 @@ public:
   };
 
   void AddOutputStream(ProcessedMediaStream* aStream, bool aFinishWhenEnded);
+  // Remove an output stream added with AddOutputStream.
+  void RemoveOutputStream(MediaStream* aStream);
 
   // Set/Unset dormant state.
   void SetDormant(bool aDormant);
@@ -159,6 +161,7 @@ private:
   void InitializationTask();
 
   void DispatchAudioCaptured();
+  void DispatchAudioUncaptured();
 
   void Shutdown();
 public: