Bug 804387. Part 8: Create AudioNodeEngine and AudioNodeStream. r=jesup

Modifies MediaStreamGraph to always advance its time by a multiple of
WEBAUDIO_BLOCK_SIZE.

--HG--
extra : rebase_source : 99524b09edd4ac0e1bc6607f2ba14925bc2f11c2

content/media/AudioNodeEngine.cpp

@@ -0,0 +1,71 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "AudioNodeEngine.h"
+
+namespace mozilla {
+
+void
+AllocateAudioBlock(uint32_t aChannelCount, AudioChunk* aChunk)
+{
+  // XXX for SIMD purposes we should do something here to make sure the
+  // channel buffers are 16-byte aligned.
+  nsRefPtr<SharedBuffer> buffer =
+    SharedBuffer::Create(WEBAUDIO_BLOCK_SIZE*aChannelCount*sizeof(float));
+  aChunk->mDuration = WEBAUDIO_BLOCK_SIZE;
+  aChunk->mChannelData.SetLength(aChannelCount);
+  float* data = static_cast<float*>(buffer->Data());
+  for (uint32_t i = 0; i < aChannelCount; ++i) {
+    aChunk->mChannelData[i] = data + i*WEBAUDIO_BLOCK_SIZE;
+  }
+  aChunk->mBuffer = buffer.forget();
+  aChunk->mVolume = 1.0f;
+  aChunk->mBufferFormat = AUDIO_FORMAT_FLOAT32;
+}
+
+void
+WriteZeroesToAudioBlock(AudioChunk* aChunk, uint32_t aStart, uint32_t aLength)
+{
+  MOZ_ASSERT(aStart + aLength <= WEBAUDIO_BLOCK_SIZE);
+  if (aLength == 0)
+    return;
+  for (uint32_t i = 0; i < aChunk->mChannelData.Length(); ++i) {
+    memset(static_cast<float*>(const_cast<void*>(aChunk->mChannelData[i])) + aStart,
+           0, aLength*sizeof(float));
+  }
+}
+
+void
+AudioBlockAddChannelWithScale(const float aInput[WEBAUDIO_BLOCK_SIZE],
+                              float aScale,
+                              float aOutput[WEBAUDIO_BLOCK_SIZE])
+{
+  if (aScale == 1.0f) {
+    for (uint32_t i = 0; i < WEBAUDIO_BLOCK_SIZE; ++i) {
+      aOutput[i] += aInput[i];
+    }
+  } else {
+    for (uint32_t i = 0; i < WEBAUDIO_BLOCK_SIZE; ++i) {
+      aOutput[i] += aInput[i]*aScale;
+    }
+  }
+}
+
+void
+AudioBlockCopyChannelWithScale(const float aInput[WEBAUDIO_BLOCK_SIZE],
+                               float aScale,
+                               float aOutput[WEBAUDIO_BLOCK_SIZE])
+{
+  if (aScale == 1.0f) {
+    memcpy(aOutput, aInput, WEBAUDIO_BLOCK_SIZE*sizeof(float));
+  } else {
+    for (uint32_t i = 0; i < WEBAUDIO_BLOCK_SIZE; ++i) {
+      aOutput[i] = aInput[i]*aScale;
+    }
+  }
+}
+
+}

content/media/AudioNodeEngine.h

@@ -0,0 +1,149 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+#ifndef MOZILLA_AUDIONODEENGINE_H_
+#define MOZILLA_AUDIONODEENGINE_H_
+
+#include "AudioSegment.h"
+
+namespace mozilla {
+
+class AudioNodeStream;
+
+// We ensure that the graph advances in steps that are multiples of the Web
+// Audio block size
+const uint32_t WEBAUDIO_BLOCK_SIZE_BITS = 7;
+const uint32_t WEBAUDIO_BLOCK_SIZE = 1 << WEBAUDIO_BLOCK_SIZE_BITS;
+
+/**
+ * This class holds onto a set of immutable channel buffers. The storage
+ * for the buffers must be malloced, but the buffer pointers and the malloc
+ * pointers can be different (e.g. if the buffers are contained inside
+ * some malloced object).
+ */
+class ThreadSharedFloatArrayBufferList : public ThreadSharedObject {
+public:
+  /**
+   * Construct with null data.
+   */
+  ThreadSharedFloatArrayBufferList(uint32_t aCount)
+  {
+    mContents.SetLength(aCount);
+  }
+
+  struct Storage {
+    Storage()
+    {
+      mDataToFree = nullptr;
+      mSampleData = nullptr;
+    }
+    ~Storage() { free(mDataToFree); }
+    void* mDataToFree;
+    const float* mSampleData;
+  };
+
+  /**
+   * This can be called on any thread.
+   */
+  uint32_t GetChannels() const { return mContents.Length(); }
+  /**
+   * This can be called on any thread.
+   */
+  const float* GetData(uint32_t aIndex) const { return mContents[aIndex].mSampleData; }
+
+  /**
+   * Call this only during initialization, before the object is handed to
+   * any other thread.
+   */
+  void SetData(uint32_t aIndex, void* aDataToFree, const float* aData)
+  {
+    Storage* s = &mContents[aIndex];
+    free(s->mDataToFree);
+    s->mDataToFree = aDataToFree;
+    s->mSampleData = aData;
+  }
+
+  /**
+   * Put this object into an error state where there are no channels.
+   */
+  void Clear() { mContents.Clear(); }
+
+private:
+  AutoFallibleTArray<Storage,2> mContents;
+};
+
+/**
+ * Allocates an AudioChunk with fresh buffers of WEBAUDIO_BLOCK_SIZE float samples.
+ * AudioChunk::mChannelData's entries can be cast to float* for writing.
+ */
+void AllocateAudioBlock(uint32_t aChannelCount, AudioChunk* aChunk);
+
+/**
+ * aChunk must have been allocated by AllocateAudioBlock.
+ */
+void WriteZeroesToAudioBlock(AudioChunk* aChunk, uint32_t aStart, uint32_t aLength);
+
+/**
+ * Pointwise multiply-add operation. aScale == 1.0f should be optimized.
+ */
+void AudioBlockAddChannelWithScale(const float aInput[WEBAUDIO_BLOCK_SIZE],
+                                   float aScale,
+                                   float aOutput[WEBAUDIO_BLOCK_SIZE]);
+
+/**
+ * Pointwise copy-scaled operation. aScale == 1.0f should be optimized.
+ */
+void AudioBlockCopyChannelWithScale(const float aInput[WEBAUDIO_BLOCK_SIZE],
+                                    float aScale,
+                                    float aOutput[WEBAUDIO_BLOCK_SIZE]);
+
+/**
+ * All methods of this class and its subclasses are called on the
+ * MediaStreamGraph thread.
+ */
+class AudioNodeEngine {
+public:
+  AudioNodeEngine() {}
+  virtual ~AudioNodeEngine() {}
+
+  virtual void SetStreamTimeParameter(uint32_t aIndex, TrackTicks aParam)
+  {
+    NS_ERROR("Invalid SetStreamTimeParameter index");
+  }
+  virtual void SetDoubleParameter(uint32_t aIndex, double aParam)
+  {
+    NS_ERROR("Invalid SetDoubleParameter index");
+  }
+  virtual void SetInt32Parameter(uint32_t aIndex, int32_t aParam)
+  {
+    NS_ERROR("Invalid SetInt32Parameter index");
+  }
+  virtual void SetBuffer(already_AddRefed<ThreadSharedFloatArrayBufferList> aBuffer)
+  {
+    NS_ERROR("SetBuffer called on engine that doesn't support it");
+  }
+
+  /**
+   * Produce the next block of audio samples, given input samples aInput
+   * (the mixed data for input 0).
+   * By default, simply returns the mixed input.
+   * aInput is guaranteed to have float sample format (if it has samples at all)
+   * and to have been resampled to IdealAudioRate(), and to have exactly
+   * WEBAUDIO_BLOCK_SIZE samples.
+   * *aFinished is set to false by the caller. If the callee sets it to true,
+   * we'll finish the stream and not call this again.
+   */
+  virtual void ProduceAudioBlock(AudioNodeStream* aStream,
+                                 const AudioChunk& aInput,
+                                 AudioChunk* aOutput,
+                                 bool* aFinished)
+  {
+    *aOutput = aInput;
+  }
+};
+
+}
+
+#endif /* MOZILLA_AUDIONODEENGINE_H_ */

content/media/AudioNodeStream.cpp

@@ -0,0 +1,270 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-*/
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "AudioNodeStream.h"
+
+#include "MediaStreamGraphImpl.h"
+#include "AudioNodeEngine.h"
+
+using namespace mozilla::dom;
+
+namespace mozilla {
+
+/**
+ * An AudioNodeStream produces a single audio track with ID
+ * AUDIO_NODE_STREAM_TRACK_ID. This track has rate IdealAudioRate().
+ * Each chunk in the track is a single block of WEBAUDIO_BLOCK_SIZE samples.
+ */
+static const int AUDIO_NODE_STREAM_TRACK_ID = 1;
+
+AudioNodeStream::~AudioNodeStream()
+{
+}
+
+void
+AudioNodeStream::SetStreamTimeParameter(uint32_t aIndex, MediaStream* aRelativeToStream,
+                                        double aStreamTime)
+{
+  class Message : public ControlMessage {
+  public:
+    Message(AudioNodeStream* aStream, uint32_t aIndex, MediaStream* aRelativeToStream,
+            double aStreamTime)
+      : ControlMessage(aStream), mStreamTime(aStreamTime),
+        mRelativeToStream(aRelativeToStream), mIndex(aIndex) {}
+    virtual void Run()
+    {
+      static_cast<AudioNodeStream*>(mStream)->
+          SetStreamTimeParameterImpl(mIndex, mRelativeToStream, mStreamTime);
+    }
+    double mStreamTime;
+    MediaStream* mRelativeToStream;
+    uint32_t mIndex;
+  };
+
+  MOZ_ASSERT(this);
+  GraphImpl()->AppendMessage(new Message(this, aIndex, aRelativeToStream, aStreamTime));
+}
+
+void
+AudioNodeStream::SetStreamTimeParameterImpl(uint32_t aIndex, MediaStream* aRelativeToStream,
+                                            double aStreamTime)
+{
+  StreamTime streamTime = std::max<MediaTime>(0, SecondsToMediaTime(aStreamTime));
+  GraphTime graphTime = aRelativeToStream->StreamTimeToGraphTime(streamTime);
+  StreamTime thisStreamTime = GraphTimeToStreamTimeOptimistic(graphTime);
+  TrackTicks ticks = TimeToTicksRoundDown(IdealAudioRate(), thisStreamTime);
+  mEngine->SetStreamTimeParameter(aIndex, ticks);
+}
+
+void
+AudioNodeStream::SetDoubleParameter(uint32_t aIndex, double aValue)
+{
+  class Message : public ControlMessage {
+  public:
+    Message(AudioNodeStream* aStream, uint32_t aIndex, double aValue)
+      : ControlMessage(aStream), mValue(aValue), mIndex(aIndex) {}
+    virtual void Run()
+    {
+      static_cast<AudioNodeStream*>(mStream)->Engine()->
+          SetDoubleParameter(mIndex, mValue);
+    }
+    double mValue;
+    uint32_t mIndex;
+  };
+
+  MOZ_ASSERT(this);
+  GraphImpl()->AppendMessage(new Message(this, aIndex, aValue));
+}
+
+void
+AudioNodeStream::SetInt32Parameter(uint32_t aIndex, int32_t aValue)
+{
+  class Message : public ControlMessage {
+  public:
+    Message(AudioNodeStream* aStream, uint32_t aIndex, int32_t aValue)
+      : ControlMessage(aStream), mValue(aValue), mIndex(aIndex) {}
+    virtual void Run()
+    {
+      static_cast<AudioNodeStream*>(mStream)->Engine()->
+          SetInt32Parameter(mIndex, mValue);
+    }
+    int32_t mValue;
+    uint32_t mIndex;
+  };
+
+  MOZ_ASSERT(this);
+  GraphImpl()->AppendMessage(new Message(this, aIndex, aValue));
+}
+
+void
+AudioNodeStream::SetBuffer(already_AddRefed<ThreadSharedFloatArrayBufferList> aBuffer)
+{
+  class Message : public ControlMessage {
+  public:
+    Message(AudioNodeStream* aStream,
+            already_AddRefed<ThreadSharedFloatArrayBufferList> aBuffer)
+      : ControlMessage(aStream), mBuffer(aBuffer) {}
+    virtual void Run()
+    {
+      static_cast<AudioNodeStream*>(mStream)->Engine()->
+          SetBuffer(mBuffer.forget());
+    }
+    nsRefPtr<ThreadSharedFloatArrayBufferList> mBuffer;
+  };
+
+  MOZ_ASSERT(this);
+  GraphImpl()->AppendMessage(new Message(this, aBuffer));
+}
+
+StreamBuffer::Track*
+AudioNodeStream::EnsureTrack()
+{
+  StreamBuffer::Track* track = mBuffer.FindTrack(AUDIO_NODE_STREAM_TRACK_ID);
+  if (!track) {
+    nsAutoPtr<MediaSegment> segment(new AudioSegment());
+    for (uint32_t j = 0; j < mListeners.Length(); ++j) {
+      MediaStreamListener* l = mListeners[j];
+      l->NotifyQueuedTrackChanges(Graph(), AUDIO_NODE_STREAM_TRACK_ID, IdealAudioRate(), 0,
+                                  MediaStreamListener::TRACK_EVENT_CREATED,
+                                  *segment);
+    }
+    track = &mBuffer.AddTrack(AUDIO_NODE_STREAM_TRACK_ID, IdealAudioRate(), 0, segment.forget());
+  }
+  return track;
+}
+
+AudioChunk*
+AudioNodeStream::ObtainInputBlock(AudioChunk* aTmpChunk)
+{
+  uint32_t inputCount = mInputs.Length();
+  uint32_t outputChannelCount = 0;
+  nsAutoTArray<AudioChunk*,250> inputChunks;
+  for (uint32_t i = 0; i < inputCount; ++i) {
+    MediaStream* s = mInputs[i]->GetSource();
+    AudioNodeStream* a = s->AsAudioNodeStream();
+    MOZ_ASSERT(a);
+    if (a->IsFinishedOnGraphThread()) {
+      continue;
+    }
+    AudioChunk* chunk = a->mLastChunk;
+    // XXX when we implement DelayNode, this will no longer be true and we'll
+    // need to treat a null chunk (when the DelayNode hasn't had a chance
+    // to produce data yet) as silence here.
+    MOZ_ASSERT(chunk);
+    if (chunk->IsNull()) {
+      continue;
+    }
+
+    inputChunks.AppendElement(chunk);
+    outputChannelCount =
+      GetAudioChannelsSuperset(outputChannelCount, chunk->mChannelData.Length());
+  }
+
+  uint32_t inputChunkCount = inputChunks.Length();
+  if (inputChunkCount == 0) {
+    aTmpChunk->SetNull(WEBAUDIO_BLOCK_SIZE);
+    return aTmpChunk;
+  }
+
+  if (inputChunkCount == 1) {
+    return inputChunks[0];
+  }
+
+  AllocateAudioBlock(outputChannelCount, aTmpChunk);
+
+  for (uint32_t i = 0; i < inputChunkCount; ++i) {
+    AudioChunk* chunk = inputChunks[i];
+    nsAutoTArray<const void*,GUESS_AUDIO_CHANNELS> channels;
+    channels.AppendElements(chunk->mChannelData);
+    if (channels.Length() < outputChannelCount) {
+      AudioChannelsUpMix(&channels, outputChannelCount, nullptr);
+      NS_ASSERTION(outputChannelCount == channels.Length(),
+                   "We called GetAudioChannelsSuperset to avoid this");
+    }
+
+    for (uint32_t c = 0; c < channels.Length(); ++c) {
+      const float* inputData = static_cast<const float*>(channels[c]);
+      float* outputData = static_cast<float*>(const_cast<void*>(aTmpChunk->mChannelData[c]));
+      if (inputData) {
+        if (i == 0) {
+          AudioBlockCopyChannelWithScale(inputData, chunk->mVolume, outputData);
+        } else {
+          AudioBlockAddChannelWithScale(inputData, chunk->mVolume, outputData);
+        }
+      } else {
+        if (i == 0) {
+          memset(outputData, 0, WEBAUDIO_BLOCK_SIZE*sizeof(float));
+        }
+      }
+    }
+  }
+
+  return aTmpChunk;
+}
+
+// The MediaStreamGraph guarantees that this is actually one block, for
+// AudioNodeStreams.
+void
+AudioNodeStream::ProduceOutput(GraphTime aFrom, GraphTime aTo)
+{
+  StreamBuffer::Track* track = EnsureTrack();
+
+  AudioChunk outputChunk;
+  AudioSegment* segment = track->Get<AudioSegment>();
+
+  if (mInCycle) {
+    // XXX DelayNode not supported yet so just produce silence
+    outputChunk.SetNull(WEBAUDIO_BLOCK_SIZE);
+  } else {
+    AudioChunk tmpChunk;
+    AudioChunk* inputChunk = ObtainInputBlock(&tmpChunk);
+    bool finished = false;
+    mEngine->ProduceAudioBlock(this, *inputChunk, &outputChunk, &finished);
+    if (finished) {
+      FinishOutput();
+    }
+  }
+
+  mLastChunk = segment->AppendAndConsumeChunk(&outputChunk);
+
+  for (uint32_t j = 0; j < mListeners.Length(); ++j) {
+    MediaStreamListener* l = mListeners[j];
+    AudioChunk copyChunk = *mLastChunk;
+    AudioSegment tmpSegment;
+    tmpSegment.AppendAndConsumeChunk(&copyChunk);
+    l->NotifyQueuedTrackChanges(Graph(), AUDIO_NODE_STREAM_TRACK_ID,
+                                IdealAudioRate(), segment->GetDuration(), 0,
+                                tmpSegment);
+  }
+}
+
+TrackTicks
+AudioNodeStream::GetCurrentPosition()
+{
+  return EnsureTrack()->Get<AudioSegment>()->GetDuration();
+}
+
+void
+AudioNodeStream::FinishOutput()
+{
+  if (IsFinishedOnGraphThread()) {
+    return;
+  }
+
+  StreamBuffer::Track* track = EnsureTrack();
+  track->SetEnded();
+  FinishOnGraphThread();
+
+  for (uint32_t j = 0; j < mListeners.Length(); ++j) {
+    MediaStreamListener* l = mListeners[j];
+    AudioSegment emptySegment;
+    l->NotifyQueuedTrackChanges(Graph(), AUDIO_NODE_STREAM_TRACK_ID,
+                                IdealAudioRate(),
+                                track->GetSegment()->GetDuration(),
+                                MediaStreamListener::TRACK_EVENT_ENDED, emptySegment);
+  }
+}
+
+}

content/media/AudioNodeStream.h

@@ -0,0 +1,82 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-*/
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef MOZILLA_AUDIONODESTREAM_H_
+#define MOZILLA_AUDIONODESTREAM_H_
+
+#include "MediaStreamGraph.h"
+#include "AudioChannelFormat.h"
+#include "AudioNodeEngine.h"
+
+#ifdef PR_LOGGING
+#define LOG(type, msg) PR_LOG(gMediaStreamGraphLog, type, msg)
+#else
+#define LOG(type, msg)
+#endif
+
+namespace mozilla {
+
+class ThreadSharedFloatArrayBufferList;
+
+/**
+ * An AudioNodeStream produces one audio track with ID AUDIO_TRACK.
+ * The start time of the AudioTrack is aligned to the start time of the
+ * AudioContext's destination node stream, plus some multiple of BLOCK_SIZE
+ * samples.
+ *
+ * An AudioNodeStream has an AudioNodeEngine plugged into it that does the
+ * actual audio processing. AudioNodeStream contains the glue code that
+ * integrates audio processing with the MediaStreamGraph.
+ */
+class AudioNodeStream : public ProcessedMediaStream {
+public:
+  enum { AUDIO_TRACK = 1 };
+
+  /**
+   * Transfers ownership of aEngine to the new AudioNodeStream.
+   */
+  explicit AudioNodeStream(AudioNodeEngine* aEngine)
+    : ProcessedMediaStream(nullptr), mEngine(aEngine), mLastChunk(nullptr)
+  {
+  }
+  ~AudioNodeStream();
+
+  // Control API
+  /**
+   * Sets a parameter that's a time relative to some stream's played time.
+   * This time is converted to a time relative to this stream when it's set.
+   */
+  void SetStreamTimeParameter(uint32_t aIndex, MediaStream* aRelativeToStream,
+                              double aStreamTime);
+  void SetDoubleParameter(uint32_t aIndex, double aValue);
+  void SetInt32Parameter(uint32_t aIndex, int32_t aValue);
+  void SetBuffer(already_AddRefed<ThreadSharedFloatArrayBufferList> aBuffer);
+
+  virtual AudioNodeStream* AsAudioNodeStream() { return this; }
+
+  // Graph thread only
+  void SetStreamTimeParameterImpl(uint32_t aIndex, MediaStream* aRelativeToStream,
+                                  double aStreamTime);
+  virtual void ProduceOutput(GraphTime aFrom, GraphTime aTo);
+  TrackTicks GetCurrentPosition();
+
+  // Any thread
+  AudioNodeEngine* Engine() { return mEngine; }
+
+protected:
+  void FinishOutput();
+
+  StreamBuffer::Track* EnsureTrack();
+  AudioChunk* ObtainInputBlock(AudioChunk* aTmpChunk);
+
+  // The engine that will generate output for this node.
+  nsAutoPtr<AudioNodeEngine> mEngine;
+  // The last block produced by this node.
+  AudioChunk* mLastChunk;
+};
+
+}
+
+#endif /* MOZILLA_AUDIONODESTREAM_H_ */

content/media/AudioSegment.cpp

@@ -89,7 +89,6 @@ AudioSegment::ApplyVolume(float aVolume)
 }
 
 static const int AUDIO_PROCESSING_FRAMES = 640; /* > 10ms of 48KHz audio */
-static const int GUESS_AUDIO_CHANNELS = 2;
 static const uint8_t gZeroChannel[MAX_AUDIO_SAMPLE_SIZE*AUDIO_PROCESSING_FRAMES] = {0};
 
 void

content/media/AudioSegment.h

@@ -15,6 +15,11 @@ namespace mozilla {
 
 class AudioStream;
 
+/**
+ * For auto-arrays etc, guess this as the common number of channels.
+ */
+const int GUESS_AUDIO_CHANNELS = 2;
+
 /**
  * An AudioChunk represents a multi-channel buffer of audio samples.
  * It references an underlying ThreadSharedObject which manages the lifetime

content/media/Makefile.in

@@ -19,6 +19,8 @@ endif # !_MSC_VER
 EXPORTS = \
   AbstractMediaDecoder.h \
   AudioChannelFormat.h \
+  AudioNodeEngine.h \
+  AudioNodeStream.h \
   AudioSampleFormat.h \
   AudioSegment.h \
   BufferMediaResource.h \
@@ -46,6 +48,8 @@ EXPORTS = \
 
 CPPSRCS = \
   AudioChannelFormat.cpp \
+  AudioNodeEngine.cpp \
+  AudioNodeStream.cpp \
   AudioSegment.cpp \
   DecoderTraits.cpp \
   FileBlockCache.cpp \

content/media/MediaStreamGraph.cpp

@@ -19,6 +19,8 @@
 #include "TrackUnionStream.h"
 #include "ImageContainer.h"
 #include "AudioChannelCommon.h"
+#include "AudioNodeEngine.h"
+#include "AudioNodeStream.h"
 #include <algorithm>
 
 using namespace mozilla::layers;
@@ -874,6 +876,40 @@ MediaStreamGraphImpl::EnsureNextIterationLocked(MonitorAutoLock& aLock)
   }
 }
 
+static GraphTime
+RoundUpToAudioBlock(GraphTime aTime)
+{
+  TrackRate rate = IdealAudioRate();
+  int64_t ticksAtIdealRate = (aTime*rate) >> MEDIA_TIME_FRAC_BITS;
+  // Round up to nearest block boundary
+  int64_t blocksAtIdealRate =
+    (ticksAtIdealRate + (WEBAUDIO_BLOCK_SIZE - 1)) >>
+    WEBAUDIO_BLOCK_SIZE_BITS;
+  // Round up to nearest MediaTime unit
+  return
+    ((((blocksAtIdealRate + 1)*WEBAUDIO_BLOCK_SIZE) << MEDIA_TIME_FRAC_BITS)
+     + rate - 1)/rate;
+}
+
+void
+MediaStreamGraphImpl::ProduceDataForStreamsBlockByBlock(uint32_t aStreamIndex,
+                                                        GraphTime aFrom,
+                                                        GraphTime aTo)
+{
+  GraphTime t = aFrom;
+  while (t < aTo) {
+    GraphTime next = RoundUpToAudioBlock(t + 1);
+    for (uint32_t i = aStreamIndex; i < mStreams.Length(); ++i) {
+      ProcessedMediaStream* ps = mStreams[i]->AsProcessedStream();
+      if (ps) {
+        ps->ProduceOutput(t, next);
+      }
+    }
+    t = next;
+  }
+  NS_ASSERTION(t == aTo, "Something went wrong with rounding to block boundaries");
+}
+
 void
 MediaStreamGraphImpl::RunThread()
 {
@@ -905,9 +941,8 @@ MediaStreamGraphImpl::RunThread()
 
     UpdateStreamOrder();
 
-    int32_t writeAudioUpTo = AUDIO_TARGET_MS;
     GraphTime endBlockingDecisions =
-      mCurrentTime + MillisecondsToMediaTime(writeAudioUpTo);
+      RoundUpToAudioBlock(mCurrentTime + MillisecondsToMediaTime(AUDIO_TARGET_MS));
     bool ensureNextIteration = false;
 
     // Grab pending stream input.
@@ -926,15 +961,27 @@ MediaStreamGraphImpl::RunThread()
     // Play stream contents.
     uint32_t audioStreamsActive = 0;
     bool allBlockedForever = true;
+    // True when we've done ProduceOutput for all processed streams.
+    bool doneAllProducing = false;
     // Figure out what each stream wants to do
     for (uint32_t i = 0; i < mStreams.Length(); ++i) {
       MediaStream* stream = mStreams[i];
-      ProcessedMediaStream* ps = stream->AsProcessedStream();
-      if (ps && !ps->mFinished) {
-        ps->ProduceOutput(prevComputedTime, mStateComputedTime);
-        NS_ASSERTION(stream->mBuffer.GetEnd() >=
-                     GraphTimeToStreamTime(stream, mStateComputedTime),
-                     "Stream did not produce enough data");
+      if (!doneAllProducing && !stream->IsFinishedOnGraphThread()) {
+        ProcessedMediaStream* ps = stream->AsProcessedStream();
+        if (ps) {
+          AudioNodeStream* n = stream->AsAudioNodeStream();
+          if (n) {
+            // Since an AudioNodeStream is present, go ahead and
+            // produce audio block by block for all the rest of the streams.
+            ProduceDataForStreamsBlockByBlock(i, prevComputedTime, mStateComputedTime);
+            doneAllProducing = true;
+          } else {
+            ps->ProduceOutput(prevComputedTime, mStateComputedTime);
+            NS_ASSERTION(stream->mBuffer.GetEnd() >=
+                         GraphTimeToStreamTime(stream, mStateComputedTime),
+                       "Stream did not produce enough data");
+          }
+        }
       }
       NotifyHasCurrentData(stream);
       CreateOrDestroyAudioStreams(prevComputedTime, stream);
@@ -1896,4 +1943,13 @@ MediaStreamGraph::CreateTrackUnionStream(nsDOMMediaStream* aWrapper)
   return stream;
 }
 
+AudioNodeStream*
+MediaStreamGraph::CreateAudioNodeStream(AudioNodeEngine* aEngine)
+{
+  AudioNodeStream* stream = new AudioNodeStream(aEngine);
+  NS_ADDREF(stream);
+  static_cast<MediaStreamGraphImpl*>(this)->AppendMessage(new CreateMessage(stream));
+  return stream;
+}
+
 }

content/media/MediaStreamGraph.h

@@ -189,6 +189,9 @@ class MediaStreamGraphImpl;
 class SourceMediaStream;
 class ProcessedMediaStream;
 class MediaInputPort;
+class AudioNodeStream;
+class AudioNodeEngine;
+struct AudioChunk;
 
 /**
  * A stream of synchronized audio and video data. All (not blocked) streams
@@ -345,6 +348,7 @@ public:
 
   virtual SourceMediaStream* AsSourceStream() { return nullptr; }
   virtual ProcessedMediaStream* AsProcessedStream() { return nullptr; }
+  virtual AudioNodeStream* AsAudioNodeStream() { return nullptr; }
 
   // media graph thread only
   void Init();
@@ -819,12 +823,20 @@ protected:
   bool mInCycle;
 };
 
+// Returns ideal audio rate for processing
+inline TrackRate IdealAudioRate() { return 48000; }
+
 /**
  * Initially, at least, we will have a singleton MediaStreamGraph per
  * process.
  */
 class MediaStreamGraph {
 public:
+  // We ensure that the graph current time advances in multiples of
+  // IdealAudioBlockSize()/IdealAudioRate(). A stream that never blocks
+  // and has a track with the ideal audio rate will produce audio in
+  // multiples of the block size.
+
   // Main thread only
   static MediaStreamGraph* GetInstance();
   // Control API.
@@ -848,6 +860,11 @@ public:
    * particular tracks of each input stream.
    */
   ProcessedMediaStream* CreateTrackUnionStream(nsDOMMediaStream* aWrapper);
+  /**
+   * Create a stream that will process audio for an AudioNode.
+   * Takes ownership of aEngine.
+   */
+  AudioNodeStream* CreateAudioNodeStream(AudioNodeEngine* aEngine);
   /**
    * Returns the number of graph updates sent. This can be used to track
    * whether a given update has been processed by the graph thread and reflected

content/media/MediaStreamGraphImpl.h

@@ -249,6 +249,19 @@ public:
   void RecomputeBlockingAt(const nsTArray<MediaStream*>& aStreams,
                            GraphTime aTime, GraphTime aEndBlockingDecisions,
                            GraphTime* aEnd);
+  /**
+   * Produce data for all streams >= aStreamIndex for the given time interval.
+   * Advances block by block, each iteration producing data for all streams
+   * for a single block.
+   * This is needed if there are WebAudio delay nodes, whose output for a block
+   * may depend on the output of any other node (including itself) for the
+   * previous block. This is probably also more performant due to better memory
+   * locality.
+   * This is called whenever we have an AudioNodeStream in the graph.
+   */
+  void ProduceDataForStreamsBlockByBlock(uint32_t aStreamIndex,
+                                         GraphTime aFrom,
+                                         GraphTime aTo);
   /**
    * Returns true if aStream will underrun at aTime for its own playback.
    * aEndBlockingDecisions is when we plan to stop making blocking decisions.