1 files changed, 723 insertions, 0 deletions

diff --git a/dom/media/webaudio/AudioNodeTrack.cpp b/dom/media/webaudio/AudioNodeTrack.cpp
new file mode 100644
index 0000000000..7444c76822
--- /dev/null
+++ b/dom/media/webaudio/AudioNodeTrack.cpp
@@ -0,0 +1,723 @@
+/* -*- 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 "AudioNodeTrack.h"
+
+#include "MediaTrackGraphImpl.h"
+#include "MediaTrackListener.h"
+#include "AudioNodeEngine.h"
+#include "ThreeDPoint.h"
+#include "Tracing.h"
+#include "AudioChannelFormat.h"
+#include "AudioParamTimeline.h"
+#include "AudioContext.h"
+#include "nsMathUtils.h"
+#include "AlignmentUtils.h"
+#include "blink/Reverb.h"
+
+using namespace mozilla::dom;
+
+namespace mozilla {
+
+/**
+ * An AudioNodeTrack produces a single audio track with ID
+ * AUDIO_TRACK. This track has rate AudioContext::sIdealAudioRate
+ * for regular audio contexts, and the rate requested by the web content
+ * for offline audio contexts.
+ * Each chunk in the track is a single block of WEBAUDIO_BLOCK_SIZE samples.
+ * Note: This must be a different value than MEDIA_STREAM_DEST_TRACK_ID
+ */
+
+AudioNodeTrack::AudioNodeTrack(AudioNodeEngine* aEngine, Flags aFlags,
+                               TrackRate aSampleRate)
+    : ProcessedMediaTrack(
+          aSampleRate, MediaSegment::AUDIO,
+          (aFlags & EXTERNAL_OUTPUT) ? new AudioSegment() : nullptr),
+      mEngine(aEngine),
+      mFlags(aFlags),
+      mNumberOfInputChannels(2),
+      mIsActive(aEngine->IsActive()),
+      mMarkAsEndedAfterThisBlock(false),
+      mAudioParamTrack(false),
+      mPassThrough(false) {
+  MOZ_ASSERT(NS_IsMainThread());
+  mSuspendedCount = !(mIsActive || mFlags & EXTERNAL_OUTPUT);
+  mChannelCountMode = ChannelCountMode::Max;
+  mChannelInterpretation = ChannelInterpretation::Speakers;
+  mLastChunks.SetLength(std::max(uint16_t(1), mEngine->OutputCount()));
+  MOZ_COUNT_CTOR(AudioNodeTrack);
+}
+
+AudioNodeTrack::~AudioNodeTrack() {
+  MOZ_ASSERT(mActiveInputCount == 0);
+  MOZ_COUNT_DTOR(AudioNodeTrack);
+}
+
+void AudioNodeTrack::OnGraphThreadDone() { mEngine->OnGraphThreadDone(); }
+
+void AudioNodeTrack::DestroyImpl() {
+  // These are graph thread objects, so clean up on graph thread.
+  mInputChunks.Clear();
+  mLastChunks.Clear();
+
+  ProcessedMediaTrack::DestroyImpl();
+}
+
+/* static */
+already_AddRefed<AudioNodeTrack> AudioNodeTrack::Create(
+    AudioContext* aCtx, AudioNodeEngine* aEngine, Flags aFlags,
+    MediaTrackGraph* aGraph) {
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_RELEASE_ASSERT(aGraph);
+
+  // MediaRecorders use an AudioNodeTrack, but no AudioNode
+  AudioNode* node = aEngine->NodeMainThread();
+
+  RefPtr<AudioNodeTrack> track =
+      new AudioNodeTrack(aEngine, aFlags, aGraph->GraphRate());
+  if (node) {
+    track->SetChannelMixingParametersImpl(node->ChannelCount(),
+                                          node->ChannelCountModeValue(),
+                                          node->ChannelInterpretationValue());
+  }
+  // All realtime tracks are initially suspended.
+  // ApplyAudioContextOperation() is used to start tracks so that a new track
+  // will not be started before the existing tracks, which may be awaiting an
+  // AudioCallbackDriver to resume.
+  bool isRealtime = !aCtx->IsOffline();
+  track->mSuspendedCount += isRealtime;
+  aGraph->AddTrack(track);
+  if (isRealtime && !aCtx->ShouldSuspendNewTrack()) {
+    nsTArray<RefPtr<mozilla::MediaTrack>> tracks;
+    tracks.AppendElement(track);
+    aGraph->ApplyAudioContextOperation(aCtx->DestinationTrack(),
+                                       std::move(tracks),
+                                       AudioContextOperation::Resume);
+  }
+  return track.forget();
+}
+
+size_t AudioNodeTrack::SizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const {
+  size_t amount = 0;
+
+  // Not reported:
+  // - mEngine
+
+  amount += ProcessedMediaTrack::SizeOfExcludingThis(aMallocSizeOf);
+  amount += mLastChunks.ShallowSizeOfExcludingThis(aMallocSizeOf);
+  for (size_t i = 0; i < mLastChunks.Length(); i++) {
+    // NB: This is currently unshared only as there are instances of
+    //     double reporting in DMD otherwise.
+    amount += mLastChunks[i].SizeOfExcludingThisIfUnshared(aMallocSizeOf);
+  }
+
+  return amount;
+}
+
+size_t AudioNodeTrack::SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const {
+  return aMallocSizeOf(this) + SizeOfExcludingThis(aMallocSizeOf);
+}
+
+void AudioNodeTrack::SizeOfAudioNodesIncludingThis(
+    MallocSizeOf aMallocSizeOf, AudioNodeSizes& aUsage) const {
+  // Explicitly separate out the track memory.
+  aUsage.mTrack = SizeOfIncludingThis(aMallocSizeOf);
+
+  if (mEngine) {
+    // This will fill out the rest of |aUsage|.
+    mEngine->SizeOfIncludingThis(aMallocSizeOf, aUsage);
+  }
+}
+
+void AudioNodeTrack::SetTrackTimeParameter(uint32_t aIndex,
+                                           AudioContext* aContext,
+                                           double aTrackTime) {
+  class Message final : public ControlMessage {
+   public:
+    Message(AudioNodeTrack* aTrack, uint32_t aIndex,
+            MediaTrack* aRelativeToTrack, double aTrackTime)
+        : ControlMessage(aTrack),
+          mTrackTime(aTrackTime),
+          mRelativeToTrack(aRelativeToTrack),
+          mIndex(aIndex) {}
+    void Run() override {
+      TRACE("AudioNodeTrack::SetTrackTimeParameterImpl");
+      static_cast<AudioNodeTrack*>(mTrack)->SetTrackTimeParameterImpl(
+          mIndex, mRelativeToTrack, mTrackTime);
+    }
+    double mTrackTime;
+    MediaTrack* MOZ_UNSAFE_REF(
+        "ControlMessages are processed in order.  This \
+destination track is not yet destroyed.  Its (future) destroy message will be \
+processed after this message.") mRelativeToTrack;
+    uint32_t mIndex;
+  };
+
+  GraphImpl()->AppendMessage(MakeUnique<Message>(
+      this, aIndex, aContext->DestinationTrack(), aTrackTime));
+}
+
+void AudioNodeTrack::SetTrackTimeParameterImpl(uint32_t aIndex,
+                                               MediaTrack* aRelativeToTrack,
+                                               double aTrackTime) {
+  TrackTime ticks = aRelativeToTrack->SecondsToNearestTrackTime(aTrackTime);
+  mEngine->SetTrackTimeParameter(aIndex, ticks);
+}
+
+void AudioNodeTrack::SetDoubleParameter(uint32_t aIndex, double aValue) {
+  class Message final : public ControlMessage {
+   public:
+    Message(AudioNodeTrack* aTrack, uint32_t aIndex, double aValue)
+        : ControlMessage(aTrack), mValue(aValue), mIndex(aIndex) {}
+    void Run() override {
+      TRACE("AudioNodeTrack::SetDoubleParameter");
+      static_cast<AudioNodeTrack*>(mTrack)->Engine()->SetDoubleParameter(
+          mIndex, mValue);
+    }
+    double mValue;
+    uint32_t mIndex;
+  };
+
+  GraphImpl()->AppendMessage(MakeUnique<Message>(this, aIndex, aValue));
+}
+
+void AudioNodeTrack::SetInt32Parameter(uint32_t aIndex, int32_t aValue) {
+  class Message final : public ControlMessage {
+   public:
+    Message(AudioNodeTrack* aTrack, uint32_t aIndex, int32_t aValue)
+        : ControlMessage(aTrack), mValue(aValue), mIndex(aIndex) {}
+    void Run() override {
+      TRACE("AudioNodeTrack::SetInt32Parameter");
+      static_cast<AudioNodeTrack*>(mTrack)->Engine()->SetInt32Parameter(mIndex,
+                                                                        mValue);
+    }
+    int32_t mValue;
+    uint32_t mIndex;
+  };
+
+  GraphImpl()->AppendMessage(MakeUnique<Message>(this, aIndex, aValue));
+}
+
+void AudioNodeTrack::SendTimelineEvent(uint32_t aIndex,
+                                       const AudioTimelineEvent& aEvent) {
+  class Message final : public ControlMessage {
+   public:
+    Message(AudioNodeTrack* aTrack, uint32_t aIndex,
+            const AudioTimelineEvent& aEvent)
+        : ControlMessage(aTrack),
+          mEvent(aEvent),
+          mSampleRate(aTrack->mSampleRate),
+          mIndex(aIndex) {}
+    void Run() override {
+      TRACE("AudioNodeTrack::RecvTimelineEvent");
+      static_cast<AudioNodeTrack*>(mTrack)->Engine()->RecvTimelineEvent(mIndex,
+                                                                        mEvent);
+    }
+    AudioTimelineEvent mEvent;
+    TrackRate mSampleRate;
+    uint32_t mIndex;
+  };
+  GraphImpl()->AppendMessage(MakeUnique<Message>(this, aIndex, aEvent));
+}
+
+void AudioNodeTrack::SetBuffer(AudioChunk&& aBuffer) {
+  class Message final : public ControlMessage {
+   public:
+    Message(AudioNodeTrack* aTrack, AudioChunk&& aBuffer)
+        : ControlMessage(aTrack), mBuffer(aBuffer) {}
+    void Run() override {
+      TRACE("AudioNodeTrack::SetBuffer");
+      static_cast<AudioNodeTrack*>(mTrack)->Engine()->SetBuffer(
+          std::move(mBuffer));
+    }
+    AudioChunk mBuffer;
+  };
+
+  GraphImpl()->AppendMessage(MakeUnique<Message>(this, std::move(aBuffer)));
+}
+
+void AudioNodeTrack::SetReverb(WebCore::Reverb* aReverb,
+                               uint32_t aImpulseChannelCount) {
+  class Message final : public ControlMessage {
+   public:
+    Message(AudioNodeTrack* aTrack, WebCore::Reverb* aReverb,
+            uint32_t aImpulseChannelCount)
+        : ControlMessage(aTrack),
+          mReverb(aReverb),
+          mImpulseChanelCount(aImpulseChannelCount) {}
+    void Run() override {
+      TRACE("AudioNodeTrack::SetReverb");
+      static_cast<AudioNodeTrack*>(mTrack)->Engine()->SetReverb(
+          mReverb.release(), mImpulseChanelCount);
+    }
+    UniquePtr<WebCore::Reverb> mReverb;
+    uint32_t mImpulseChanelCount;
+  };
+
+  GraphImpl()->AppendMessage(
+      MakeUnique<Message>(this, aReverb, aImpulseChannelCount));
+}
+
+void AudioNodeTrack::SetRawArrayData(nsTArray<float>&& aData) {
+  class Message final : public ControlMessage {
+   public:
+    Message(AudioNodeTrack* aTrack, nsTArray<float>&& aData)
+        : ControlMessage(aTrack), mData(std::move(aData)) {}
+    void Run() override {
+      TRACE("AudioNodeTrack::SetRawArrayData");
+      static_cast<AudioNodeTrack*>(mTrack)->Engine()->SetRawArrayData(
+          std::move(mData));
+    }
+    nsTArray<float> mData;
+  };
+
+  GraphImpl()->AppendMessage(MakeUnique<Message>(this, std::move(aData)));
+}
+
+void AudioNodeTrack::SetChannelMixingParameters(
+    uint32_t aNumberOfChannels, ChannelCountMode aChannelCountMode,
+    ChannelInterpretation aChannelInterpretation) {
+  class Message final : public ControlMessage {
+   public:
+    Message(AudioNodeTrack* aTrack, uint32_t aNumberOfChannels,
+            ChannelCountMode aChannelCountMode,
+            ChannelInterpretation aChannelInterpretation)
+        : ControlMessage(aTrack),
+          mNumberOfChannels(aNumberOfChannels),
+          mChannelCountMode(aChannelCountMode),
+          mChannelInterpretation(aChannelInterpretation) {}
+    void Run() override {
+      TRACE("AudioNodeTrack::SetChannelMixingParameters");
+      static_cast<AudioNodeTrack*>(mTrack)->SetChannelMixingParametersImpl(
+          mNumberOfChannels, mChannelCountMode, mChannelInterpretation);
+    }
+    uint32_t mNumberOfChannels;
+    ChannelCountMode mChannelCountMode;
+    ChannelInterpretation mChannelInterpretation;
+  };
+
+  GraphImpl()->AppendMessage(MakeUnique<Message>(
+      this, aNumberOfChannels, aChannelCountMode, aChannelInterpretation));
+}
+
+void AudioNodeTrack::SetPassThrough(bool aPassThrough) {
+  class Message final : public ControlMessage {
+   public:
+    Message(AudioNodeTrack* aTrack, bool aPassThrough)
+        : ControlMessage(aTrack), mPassThrough(aPassThrough) {}
+    void Run() override {
+      TRACE("AudioNodeTrack::SetPassThrough");
+      static_cast<AudioNodeTrack*>(mTrack)->mPassThrough = mPassThrough;
+    }
+    bool mPassThrough;
+  };
+
+  GraphImpl()->AppendMessage(MakeUnique<Message>(this, aPassThrough));
+}
+
+void AudioNodeTrack::SendRunnable(already_AddRefed<nsIRunnable> aRunnable) {
+  class Message final : public ControlMessage {
+   public:
+    Message(MediaTrack* aTrack, already_AddRefed<nsIRunnable> aRunnable)
+        : ControlMessage(aTrack), mRunnable(aRunnable) {}
+    void Run() override {
+      TRACE("AudioNodeTrack::SendRunnable");
+      mRunnable->Run();
+    }
+
+   private:
+    nsCOMPtr<nsIRunnable> mRunnable;
+  };
+
+  GraphImpl()->AppendMessage(MakeUnique<Message>(this, std::move(aRunnable)));
+}
+
+void AudioNodeTrack::SetChannelMixingParametersImpl(
+    uint32_t aNumberOfChannels, ChannelCountMode aChannelCountMode,
+    ChannelInterpretation aChannelInterpretation) {
+  mNumberOfInputChannels = aNumberOfChannels;
+  mChannelCountMode = aChannelCountMode;
+  mChannelInterpretation = aChannelInterpretation;
+}
+
+uint32_t AudioNodeTrack::ComputedNumberOfChannels(uint32_t aInputChannelCount) {
+  switch (mChannelCountMode) {
+    case ChannelCountMode::Explicit:
+      // Disregard the channel count we've calculated from inputs, and just use
+      // mNumberOfInputChannels.
+      return mNumberOfInputChannels;
+    case ChannelCountMode::Clamped_max:
+      // Clamp the computed output channel count to mNumberOfInputChannels.
+      return std::min(aInputChannelCount, mNumberOfInputChannels);
+    default:
+    case ChannelCountMode::Max:
+      // Nothing to do here, just shut up the compiler warning.
+      return aInputChannelCount;
+  }
+}
+
+uint32_t AudioNodeTrack::NumberOfChannels() const {
+  MOZ_ASSERT(GraphImpl()->OnGraphThread());
+
+  return mNumberOfInputChannels;
+}
+
+class AudioNodeTrack::AdvanceAndResumeMessage final : public ControlMessage {
+ public:
+  AdvanceAndResumeMessage(AudioNodeTrack* aTrack, TrackTime aAdvance)
+      : ControlMessage(aTrack), mAdvance(aAdvance) {}
+  void Run() override {
+    TRACE("AudioNodeTrack::AdvanceAndResumeMessage");
+    auto ns = static_cast<AudioNodeTrack*>(mTrack);
+    ns->mStartTime -= mAdvance;
+    ns->mSegment->AppendNullData(mAdvance);
+    ns->DecrementSuspendCount();
+  }
+
+ private:
+  TrackTime mAdvance;
+};
+
+void AudioNodeTrack::AdvanceAndResume(TrackTime aAdvance) {
+  mMainThreadCurrentTime += aAdvance;
+  GraphImpl()->AppendMessage(
+      MakeUnique<AdvanceAndResumeMessage>(this, aAdvance));
+}
+
+void AudioNodeTrack::ObtainInputBlock(AudioBlock& aTmpChunk,
+                                      uint32_t aPortIndex) {
+  uint32_t inputCount = mInputs.Length();
+  uint32_t outputChannelCount = 1;
+  AutoTArray<const AudioBlock*, 250> inputChunks;
+  for (uint32_t i = 0; i < inputCount; ++i) {
+    if (aPortIndex != mInputs[i]->InputNumber()) {
+      // This input is connected to a different port
+      continue;
+    }
+    MediaTrack* t = mInputs[i]->GetSource();
+    AudioNodeTrack* a = static_cast<AudioNodeTrack*>(t);
+    MOZ_ASSERT(a == t->AsAudioNodeTrack());
+    if (a->IsAudioParamTrack()) {
+      continue;
+    }
+
+    const AudioBlock* chunk = &a->mLastChunks[mInputs[i]->OutputNumber()];
+    MOZ_ASSERT(chunk);
+    if (chunk->IsNull() || chunk->mChannelData.IsEmpty()) {
+      continue;
+    }
+
+    inputChunks.AppendElement(chunk);
+    outputChannelCount =
+        GetAudioChannelsSuperset(outputChannelCount, chunk->ChannelCount());
+  }
+
+  outputChannelCount = ComputedNumberOfChannels(outputChannelCount);
+
+  uint32_t inputChunkCount = inputChunks.Length();
+  if (inputChunkCount == 0 ||
+      (inputChunkCount == 1 && inputChunks[0]->ChannelCount() == 0)) {
+    aTmpChunk.SetNull(WEBAUDIO_BLOCK_SIZE);
+    return;
+  }
+
+  if (inputChunkCount == 1 &&
+      inputChunks[0]->ChannelCount() == outputChannelCount) {
+    aTmpChunk = *inputChunks[0];
+    return;
+  }
+
+  if (outputChannelCount == 0) {
+    aTmpChunk.SetNull(WEBAUDIO_BLOCK_SIZE);
+    return;
+  }
+
+  aTmpChunk.AllocateChannels(outputChannelCount);
+  DownmixBufferType downmixBuffer;
+  ASSERT_ALIGNED16(downmixBuffer.Elements());
+
+  for (uint32_t i = 0; i < inputChunkCount; ++i) {
+    AccumulateInputChunk(i, *inputChunks[i], &aTmpChunk, &downmixBuffer);
+  }
+}
+
+void AudioNodeTrack::AccumulateInputChunk(uint32_t aInputIndex,
+                                          const AudioBlock& aChunk,
+                                          AudioBlock* aBlock,
+                                          DownmixBufferType* aDownmixBuffer) {
+  AutoTArray<const float*, GUESS_AUDIO_CHANNELS> channels;
+  UpMixDownMixChunk(&aChunk, aBlock->ChannelCount(), channels, *aDownmixBuffer);
+
+  for (uint32_t c = 0; c < channels.Length(); ++c) {
+    const float* inputData = static_cast<const float*>(channels[c]);
+    float* outputData = aBlock->ChannelFloatsForWrite(c);
+    if (inputData) {
+      if (aInputIndex == 0) {
+        AudioBlockCopyChannelWithScale(inputData, aChunk.mVolume, outputData);
+      } else {
+        AudioBlockAddChannelWithScale(inputData, aChunk.mVolume, outputData);
+      }
+    } else {
+      if (aInputIndex == 0) {
+        PodZero(outputData, WEBAUDIO_BLOCK_SIZE);
+      }
+    }
+  }
+}
+
+void AudioNodeTrack::UpMixDownMixChunk(const AudioBlock* aChunk,
+                                       uint32_t aOutputChannelCount,
+                                       nsTArray<const float*>& aOutputChannels,
+                                       DownmixBufferType& aDownmixBuffer) {
+  for (uint32_t i = 0; i < aChunk->ChannelCount(); i++) {
+    aOutputChannels.AppendElement(
+        static_cast<const float*>(aChunk->mChannelData[i]));
+  }
+  if (aOutputChannels.Length() < aOutputChannelCount) {
+    if (mChannelInterpretation == ChannelInterpretation::Speakers) {
+      AudioChannelsUpMix<float>(&aOutputChannels, aOutputChannelCount, nullptr);
+      NS_ASSERTION(aOutputChannelCount == aOutputChannels.Length(),
+                   "We called GetAudioChannelsSuperset to avoid this");
+    } else {
+      // Fill up the remaining aOutputChannels by zeros
+      for (uint32_t j = aOutputChannels.Length(); j < aOutputChannelCount;
+           ++j) {
+        aOutputChannels.AppendElement(nullptr);
+      }
+    }
+  } else if (aOutputChannels.Length() > aOutputChannelCount) {
+    if (mChannelInterpretation == ChannelInterpretation::Speakers) {
+      AutoTArray<float*, GUESS_AUDIO_CHANNELS> outputChannels;
+      outputChannels.SetLength(aOutputChannelCount);
+      aDownmixBuffer.SetLength(aOutputChannelCount * WEBAUDIO_BLOCK_SIZE);
+      for (uint32_t j = 0; j < aOutputChannelCount; ++j) {
+        outputChannels[j] = &aDownmixBuffer[j * WEBAUDIO_BLOCK_SIZE];
+      }
+
+      AudioChannelsDownMix(aOutputChannels, outputChannels.Elements(),
+                           aOutputChannelCount, WEBAUDIO_BLOCK_SIZE);
+
+      aOutputChannels.SetLength(aOutputChannelCount);
+      for (uint32_t j = 0; j < aOutputChannels.Length(); ++j) {
+        aOutputChannels[j] = outputChannels[j];
+      }
+    } else {
+      // Drop the remaining aOutputChannels
+      aOutputChannels.RemoveLastElements(aOutputChannels.Length() -
+                                         aOutputChannelCount);
+    }
+  }
+}
+
+// The MediaTrackGraph guarantees that this is actually one block, for
+// AudioNodeTracks.
+void AudioNodeTrack::ProcessInput(GraphTime aFrom, GraphTime aTo,
+                                  uint32_t aFlags) {
+  uint16_t outputCount = mLastChunks.Length();
+  MOZ_ASSERT(outputCount == std::max(uint16_t(1), mEngine->OutputCount()));
+
+  if (!mIsActive) {
+    // mLastChunks are already null.
+#ifdef DEBUG
+    for (const auto& chunk : mLastChunks) {
+      MOZ_ASSERT(chunk.IsNull());
+    }
+#endif
+  } else if (InMutedCycle()) {
+    mInputChunks.Clear();
+    for (uint16_t i = 0; i < outputCount; ++i) {
+      mLastChunks[i].SetNull(WEBAUDIO_BLOCK_SIZE);
+    }
+  } else {
+    // We need to generate at least one input
+    uint16_t maxInputs = std::max(uint16_t(1), mEngine->InputCount());
+    mInputChunks.SetLength(maxInputs);
+    for (uint16_t i = 0; i < maxInputs; ++i) {
+      ObtainInputBlock(mInputChunks[i], i);
+    }
+    bool finished = false;
+    if (mPassThrough) {
+      MOZ_ASSERT(outputCount == 1,
+                 "For now, we only support nodes that have one output port");
+      mLastChunks[0] = mInputChunks[0];
+    } else {
+      if (maxInputs <= 1 && outputCount <= 1) {
+        mEngine->ProcessBlock(this, aFrom, mInputChunks[0], &mLastChunks[0],
+                              &finished);
+      } else {
+        mEngine->ProcessBlocksOnPorts(
+            this, aFrom, Span(mInputChunks.Elements(), mEngine->InputCount()),
+            Span(mLastChunks.Elements(), mEngine->OutputCount()), &finished);
+      }
+    }
+    for (uint16_t i = 0; i < outputCount; ++i) {
+      NS_ASSERTION(mLastChunks[i].GetDuration() == WEBAUDIO_BLOCK_SIZE,
+                   "Invalid WebAudio chunk size");
+    }
+    if (finished) {
+      mMarkAsEndedAfterThisBlock = true;
+      if (mIsActive) {
+        ScheduleCheckForInactive();
+      }
+    }
+
+    if (mDisabledMode != DisabledTrackMode::ENABLED) {
+      for (uint32_t i = 0; i < outputCount; ++i) {
+        mLastChunks[i].SetNull(WEBAUDIO_BLOCK_SIZE);
+      }
+    }
+  }
+
+  if (!mEnded) {
+    // Don't output anything while finished
+    if (mFlags & EXTERNAL_OUTPUT) {
+      AdvanceOutputSegment();
+    }
+    if (mMarkAsEndedAfterThisBlock && (aFlags & ALLOW_END)) {
+      // This track was ended the last time that we looked at it, and all
+      // of the depending tracks have ended their output as well, so now
+      // it's time to mark this track as ended.
+      mEnded = true;
+    }
+  }
+}
+
+void AudioNodeTrack::ProduceOutputBeforeInput(GraphTime aFrom) {
+  MOZ_ASSERT(mEngine->AsDelayNodeEngine());
+  MOZ_ASSERT(mEngine->OutputCount() == 1,
+             "DelayNodeEngine output count should be 1");
+  MOZ_ASSERT(!InMutedCycle(), "DelayNodes should break cycles");
+  MOZ_ASSERT(mLastChunks.Length() == 1);
+
+  if (!mIsActive) {
+    mLastChunks[0].SetNull(WEBAUDIO_BLOCK_SIZE);
+  } else {
+    mEngine->ProduceBlockBeforeInput(this, aFrom, &mLastChunks[0]);
+    NS_ASSERTION(mLastChunks[0].GetDuration() == WEBAUDIO_BLOCK_SIZE,
+                 "Invalid WebAudio chunk size");
+    if (mDisabledMode != DisabledTrackMode::ENABLED) {
+      mLastChunks[0].SetNull(WEBAUDIO_BLOCK_SIZE);
+    }
+  }
+}
+
+void AudioNodeTrack::AdvanceOutputSegment() {
+  AudioSegment* segment = GetData<AudioSegment>();
+
+  AudioChunk copyChunk = *mLastChunks[0].AsMutableChunk();
+  AudioSegment tmpSegment;
+  tmpSegment.AppendAndConsumeChunk(std::move(copyChunk));
+
+  for (const auto& l : mTrackListeners) {
+    // Notify MediaTrackListeners.
+    l->NotifyQueuedChanges(Graph(), segment->GetDuration(), tmpSegment);
+  }
+
+  if (mLastChunks[0].IsNull()) {
+    segment->AppendNullData(tmpSegment.GetDuration());
+  } else {
+    segment->AppendFrom(&tmpSegment);
+  }
+}
+
+void AudioNodeTrack::AddInput(MediaInputPort* aPort) {
+  ProcessedMediaTrack::AddInput(aPort);
+  AudioNodeTrack* ns = aPort->GetSource()->AsAudioNodeTrack();
+  // Tracks that are not AudioNodeTracks are considered active.
+  if (!ns || (ns->mIsActive && !ns->IsAudioParamTrack())) {
+    IncrementActiveInputCount();
+  }
+}
+void AudioNodeTrack::RemoveInput(MediaInputPort* aPort) {
+  ProcessedMediaTrack::RemoveInput(aPort);
+  AudioNodeTrack* ns = aPort->GetSource()->AsAudioNodeTrack();
+  // Tracks that are not AudioNodeTracks are considered active.
+  if (!ns || (ns->mIsActive && !ns->IsAudioParamTrack())) {
+    DecrementActiveInputCount();
+  }
+}
+
+void AudioNodeTrack::SetActive() {
+  if (mIsActive || mMarkAsEndedAfterThisBlock) {
+    return;
+  }
+
+  mIsActive = true;
+  if (!(mFlags & EXTERNAL_OUTPUT)) {
+    DecrementSuspendCount();
+  }
+  if (IsAudioParamTrack()) {
+    // Consumers merely influence track order.
+    // They do not read from the track.
+    return;
+  }
+
+  for (const auto& consumer : mConsumers) {
+    AudioNodeTrack* ns = consumer->GetDestination()->AsAudioNodeTrack();
+    if (ns) {
+      ns->IncrementActiveInputCount();
+    }
+  }
+}
+
+class AudioNodeTrack::CheckForInactiveMessage final : public ControlMessage {
+ public:
+  explicit CheckForInactiveMessage(AudioNodeTrack* aTrack)
+      : ControlMessage(aTrack) {}
+  void Run() override {
+    TRACE("AudioNodeTrack::CheckForInactive");
+    auto ns = static_cast<AudioNodeTrack*>(mTrack);
+    ns->CheckForInactive();
+  }
+};
+
+void AudioNodeTrack::ScheduleCheckForInactive() {
+  if (mActiveInputCount > 0 && !mMarkAsEndedAfterThisBlock) {
+    return;
+  }
+
+  auto message = MakeUnique<CheckForInactiveMessage>(this);
+  GraphImpl()->RunMessageAfterProcessing(std::move(message));
+}
+
+void AudioNodeTrack::CheckForInactive() {
+  if (((mActiveInputCount > 0 || mEngine->IsActive()) &&
+       !mMarkAsEndedAfterThisBlock) ||
+      !mIsActive) {
+    return;
+  }
+
+  mIsActive = false;
+  mInputChunks.Clear();  // not required for foreseeable future
+  for (auto& chunk : mLastChunks) {
+    chunk.SetNull(WEBAUDIO_BLOCK_SIZE);
+  }
+  if (!(mFlags & EXTERNAL_OUTPUT)) {
+    IncrementSuspendCount();
+  }
+  if (IsAudioParamTrack()) {
+    return;
+  }
+
+  for (const auto& consumer : mConsumers) {
+    AudioNodeTrack* ns = consumer->GetDestination()->AsAudioNodeTrack();
+    if (ns) {
+      ns->DecrementActiveInputCount();
+    }
+  }
+}
+
+void AudioNodeTrack::IncrementActiveInputCount() {
+  ++mActiveInputCount;
+  SetActive();
+}
+
+void AudioNodeTrack::DecrementActiveInputCount() {
+  MOZ_ASSERT(mActiveInputCount > 0);
+  --mActiveInputCount;
+  CheckForInactive();
+}
+
+}  // namespace mozilla