content/media/webaudio/AudioNodeStream.h
author Karl Tomlinson <karlt+@karlt.net>
Tue, 21 Oct 2014 13:54:24 +1300
changeset 211660 3adf28ba35795442df08404b97c750ef621c095e
parent 200502 23f8315ecd6a431033e37299a42288af684e67f2
permissions -rw-r--r--
bug 1083038 be more careful about conversion of seconds to floating point ticks r=padenot Audio TrackTicks now match StreamTime so it is no longer necessary to use double seconds to convert from StreamTime to TrackTicks. Instead leave the fractional time in units of ticks/StreamTime, so that the fractional offset is calculated from the quantity that is rounded.

/* -*- 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 "mozilla/dom/AudioNodeBinding.h"
#include "AudioSegment.h"

namespace mozilla {

namespace dom {
struct ThreeDPoint;
class AudioParamTimeline;
class AudioContext;
}

class ThreadSharedFloatArrayBufferList;
class AudioNodeEngine;

/**
 * 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 {
  typedef dom::ChannelCountMode ChannelCountMode;
  typedef dom::ChannelInterpretation ChannelInterpretation;

public:
  typedef mozilla::dom::AudioContext AudioContext;

  enum { AUDIO_TRACK = 1 };

  typedef nsAutoTArray<AudioChunk, 1> OutputChunks;

  /**
   * Transfers ownership of aEngine to the new AudioNodeStream.
   */
  AudioNodeStream(AudioNodeEngine* aEngine,
                  MediaStreamGraph::AudioNodeStreamKind aKind,
                  TrackRate aSampleRate)
    : ProcessedMediaStream(nullptr),
      mEngine(aEngine),
      mSampleRate(aSampleRate),
      mKind(aKind),
      mNumberOfInputChannels(2),
      mMarkAsFinishedAfterThisBlock(false),
      mAudioParamStream(false),
      mPassThrough(false)
  {
    MOZ_ASSERT(NS_IsMainThread());
    mChannelCountMode = ChannelCountMode::Max;
    mChannelInterpretation = ChannelInterpretation::Speakers;
    // AudioNodes are always producing data
    mHasCurrentData = true;
    MOZ_COUNT_CTOR(AudioNodeStream);
  }

protected:
  ~AudioNodeStream();

public:
  // 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, AudioContext* aContext,
                              double aStreamTime);
  void SetDoubleParameter(uint32_t aIndex, double aValue);
  void SetInt32Parameter(uint32_t aIndex, int32_t aValue);
  void SetTimelineParameter(uint32_t aIndex, const dom::AudioParamTimeline& aValue);
  void SetThreeDPointParameter(uint32_t aIndex, const dom::ThreeDPoint& aValue);
  void SetBuffer(already_AddRefed<ThreadSharedFloatArrayBufferList>&& aBuffer);
  // This consumes the contents of aData.  aData will be emptied after this returns.
  void SetRawArrayData(nsTArray<float>& aData);
  void SetChannelMixingParameters(uint32_t aNumberOfChannels,
                                  ChannelCountMode aChannelCountMoe,
                                  ChannelInterpretation aChannelInterpretation);
  void SetPassThrough(bool aPassThrough);
  ChannelInterpretation GetChannelInterpretation()
  {
    return mChannelInterpretation;
  }

  void SetAudioParamHelperStream()
  {
    MOZ_ASSERT(!mAudioParamStream, "Can only do this once");
    mAudioParamStream = true;
  }

  virtual AudioNodeStream* AsAudioNodeStream() MOZ_OVERRIDE { return this; }

  // Graph thread only
  void SetStreamTimeParameterImpl(uint32_t aIndex, MediaStream* aRelativeToStream,
                                  double aStreamTime);
  void SetChannelMixingParametersImpl(uint32_t aNumberOfChannels,
                                      ChannelCountMode aChannelCountMoe,
                                      ChannelInterpretation aChannelInterpretation);
  virtual void ProcessInput(GraphTime aFrom, GraphTime aTo, uint32_t aFlags) MOZ_OVERRIDE;
  /**
   * Produce the next block of output, before input is provided.
   * ProcessInput() will be called later, and it then should not change
   * the output.  This is used only for DelayNodeEngine in a feedback loop.
   */
  void ProduceOutputBeforeInput(GraphTime aFrom);
  TrackTicks GetCurrentPosition();
  bool IsAudioParamStream() const
  {
    return mAudioParamStream;
  }

  const OutputChunks& LastChunks() const
  {
    return mLastChunks;
  }
  virtual bool MainThreadNeedsUpdates() const MOZ_OVERRIDE
  {
    // Only source and external streams need updates on the main thread.
    return (mKind == MediaStreamGraph::SOURCE_STREAM && mFinished) ||
           mKind == MediaStreamGraph::EXTERNAL_STREAM;
  }
  virtual bool IsIntrinsicallyConsumed() const MOZ_OVERRIDE
  {
    return true;
  }

  // Any thread
  AudioNodeEngine* Engine() { return mEngine; }
  TrackRate SampleRate() const { return mSampleRate; }

  /**
   * Convert a time in seconds on the destination stream to ticks
   * on this stream, including fractional position between ticks.
   */
  double FractionalTicksFromDestinationTime(AudioNodeStream* aDestination,
                                            double aSeconds);
  /**
   * Convert a time in seconds on the destination stream to nearest TrackTicks
   * on this stream.
   */
  TrackTicks TicksFromDestinationTime(MediaStream* aDestination,
                                      double aSeconds);
  /**
   * Get the destination stream time in seconds corresponding to a position on
   * this stream.
   */
  double DestinationTimeFromTicks(AudioNodeStream* aDestination,
                                  TrackTicks aPosition);

  size_t SizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const MOZ_OVERRIDE;
  size_t SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const MOZ_OVERRIDE;

  void SizeOfAudioNodesIncludingThis(MallocSizeOf aMallocSizeOf,
                                     AudioNodeSizes& aUsage) const;

protected:
  void AdvanceOutputSegment();
  void FinishOutput();
  void AccumulateInputChunk(uint32_t aInputIndex, const AudioChunk& aChunk,
                            AudioChunk* aBlock,
                            nsTArray<float>* aDownmixBuffer);
  void UpMixDownMixChunk(const AudioChunk* aChunk, uint32_t aOutputChannelCount,
                         nsTArray<const void*>& aOutputChannels,
                         nsTArray<float>& aDownmixBuffer);

  uint32_t ComputedNumberOfChannels(uint32_t aInputChannelCount);
  void ObtainInputBlock(AudioChunk& aTmpChunk, uint32_t aPortIndex);

  // The engine that will generate output for this node.
  nsAutoPtr<AudioNodeEngine> mEngine;
  // The last block produced by this node.
  OutputChunks mLastChunks;
  // The stream's sampling rate
  const TrackRate mSampleRate;
  // Whether this is an internal or external stream
  MediaStreamGraph::AudioNodeStreamKind mKind;
  // The number of input channels that this stream requires. 0 means don't care.
  uint32_t mNumberOfInputChannels;
  // The mixing modes
  ChannelCountMode mChannelCountMode;
  ChannelInterpretation mChannelInterpretation;
  // Whether the stream should be marked as finished as soon
  // as the current time range has been computed block by block.
  bool mMarkAsFinishedAfterThisBlock;
  // Whether the stream is an AudioParamHelper stream.
  bool mAudioParamStream;
  // Whether the stream just passes its input through.
  bool mPassThrough;
};

}

#endif /* MOZILLA_AUDIONODESTREAM_H_ */