Bug 855990 - Part 4: Send the buffer seen by AnalyserNodeEngine to AnalyserNode; r=padenot

--HG--
extra : rebase_source : be0b1c8197c1e8582d9dda31a74484901c665b79

content/media/webaudio/AnalyserNode.cpp

@@ -8,6 +8,7 @@
 #include "mozilla/dom/AnalyserNodeBinding.h"
 #include "AudioNodeEngine.h"
 #include "AudioNodeStream.h"
+#include "mozilla/Mutex.h"
 
 namespace mozilla {
 namespace dom {
@@ -17,13 +18,58 @@ NS_IMPL_ISUPPORTS_INHERITED0(AnalyserNode, AudioNode)
 class AnalyserNodeEngine : public AudioNodeEngine
 {
 public:
+  explicit AnalyserNodeEngine(AnalyserNode& aNode)
+    : mMutex("AnalyserNodeEngine")
+    , mNode(&aNode)
+  {
+    MOZ_ASSERT(NS_IsMainThread());
+  }
+
+  void DisconnectFromNode()
+  {
+    MutexAutoLock lock(mMutex);
+    mNode = nullptr;
+  }
+
   virtual void ProduceAudioBlock(AudioNodeStream* aStream,
                                  const AudioChunk& aInput,
                                  AudioChunk* aOutput,
                                  bool* aFinished)
   {
     *aOutput = aInput;
+
+    class TransferBuffer : public nsRunnable
+    {
+    public:
+      TransferBuffer(AnalyserNode* aNode,
+                     const AudioChunk& aChunk)
+        : mNode(aNode)
+        , mChunk(aChunk)
+      {
+      }
+
+      NS_IMETHOD Run()
+      {
+        mNode->AppendChunk(mChunk);
+        return NS_OK;
+      }
+
+    private:
+      AnalyserNode* mNode;
+      AudioChunk mChunk;
+    };
+
+    MutexAutoLock lock(mMutex);
+    if (mNode &&
+        aInput.mChannelData.Length() > 0) {
+      nsRefPtr<TransferBuffer> transfer = new TransferBuffer(mNode, aInput);
+      NS_DispatchToMainThread(transfer);
+    }
   }
+
+private:
+  Mutex mMutex;
+  AnalyserNode* mNode; // weak pointer, cleared by AnalyserNode::DestroyMediaStream
 };
 
 AnalyserNode::AnalyserNode(AudioContext* aContext)
@@ -32,9 +78,11 @@ AnalyserNode::AnalyserNode(AudioContext* aContext)
   , mMinDecibels(-100.)
   , mMaxDecibels(-30.)
   , mSmoothingTimeConstant(.8)
+  , mWriteIndex(0)
 {
-  mStream = aContext->Graph()->CreateAudioNodeStream(new AnalyserNodeEngine(),
+  mStream = aContext->Graph()->CreateAudioNodeStream(new AnalyserNodeEngine(*this),
                                                      MediaStreamGraph::INTERNAL_STREAM);
+  AllocateBuffer();
 }
 
 AnalyserNode::~AnalyserNode()
@@ -57,7 +105,10 @@ AnalyserNode::SetFftSize(uint32_t aValue, ErrorResult& aRv)
     aRv.Throw(NS_ERROR_DOM_INDEX_SIZE_ERR);
     return;
   }
-  mFFTSize = aValue;
+  if (mFFTSize != aValue) {
+    mFFTSize = aValue;
+    AllocateBuffer();
+  }
 }
 
 void
@@ -105,6 +156,57 @@ AnalyserNode::GetByteTimeDomainData(Uint8Array& aArray)
 {
 }
 
+void
+AnalyserNode::DestroyMediaStream()
+{
+  if (mStream) {
+    AudioNodeStream* ns = static_cast<AudioNodeStream*>(mStream.get());
+    AnalyserNodeEngine* engine = static_cast<AnalyserNodeEngine*>(ns->Engine());
+    engine->DisconnectFromNode();
+  }
+  AudioNode::DestroyMediaStream();
+}
+
+bool
+AnalyserNode::AllocateBuffer()
+{
+  bool result = true;
+  if (mBuffer.Length() != mFFTSize) {
+    result = mBuffer.SetLength(mFFTSize);
+    if (result) {
+      memset(mBuffer.Elements(), 0, sizeof(float) * mFFTSize);
+      mWriteIndex = 0;
+    }
+  }
+  return result;
+}
+
+void
+AnalyserNode::AppendChunk(const AudioChunk& aChunk)
+{
+  const uint32_t bufferSize = mBuffer.Length();
+  const uint32_t channelCount = aChunk.mChannelData.Length();
+  const uint32_t chunkCount = aChunk.mDuration;
+  MOZ_ASSERT((bufferSize & (bufferSize - 1)) == 0); // Must be a power of two!
+  MOZ_ASSERT(channelCount > 0);
+  MOZ_ASSERT(chunkCount == WEBAUDIO_BLOCK_SIZE);
+
+  memcpy(mBuffer.Elements() + mWriteIndex, aChunk.mChannelData[0], sizeof(float) * chunkCount);
+  for (uint32_t i = 1; i < channelCount; ++i) {
+    AudioBlockAddChannelWithScale(static_cast<const float*>(aChunk.mChannelData[i]), 1.0f,
+                                  mBuffer.Elements() + mWriteIndex);
+  }
+  if (channelCount > 1) {
+    AudioBlockInPlaceScale(mBuffer.Elements() + mWriteIndex, 1,
+                           1.0f / aChunk.mChannelData.Length());
+  }
+  mWriteIndex += chunkCount;
+  MOZ_ASSERT(mWriteIndex <= bufferSize);
+  if (mWriteIndex >= bufferSize) {
+    mWriteIndex = 0;
+  }
+}
+
 }
 }
 

content/media/webaudio/AnalyserNode.h

@@ -29,6 +29,8 @@ public:
     return true;
   }
 
+  virtual void DestroyMediaStream() MOZ_OVERRIDE;
+
   void GetFloatFrequencyData(Float32Array& aArray);
   void GetByteFrequencyData(Uint8Array& aArray);
   void GetByteTimeDomainData(Uint8Array& aArray);
@@ -57,11 +59,18 @@ public:
   }
   void SetSmoothingTimeConstant(double aValue, ErrorResult& aRv);
 
+private:
+  friend class AnalyserNodeEngine;
+  void AppendChunk(const AudioChunk& aChunk);
+  bool AllocateBuffer();
+
 private:
   uint32_t mFFTSize;
   double mMinDecibels;
   double mMaxDecibels;
   double mSmoothingTimeConstant;
+  uint32_t mWriteIndex;
+  FallibleTArray<float> mBuffer;
 };
 
 }