gecko-dev/dom/media/webaudio/AudioNodeStream.h

/* -*- 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 "nsAutoPtr.h"
#include "AlignedTArray.h"
#include "AudioBlock.h"
#include "AudioSegment.h"

namespace mozilla {

namespace dom {
struct ThreeDPoint;
struct AudioTimelineEvent;
class AudioContext;
} // namespace dom

class ThreadSharedFloatArrayBufferList;
class AudioNodeEngine;

typedef AlignedAutoTArray<float, GUESS_AUDIO_CHANNELS*WEBAUDIO_BLOCK_SIZE, 16> DownmixBufferType;

/**
 * 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 AutoTArray<AudioBlock, 1> OutputChunks;

  // Flags re main thread updates and stream output.
  typedef unsigned Flags;
  enum : Flags {
    NO_STREAM_FLAGS = 0U,
    NEED_MAIN_THREAD_FINISHED = 1U << 0,
    NEED_MAIN_THREAD_CURRENT_TIME = 1U << 1,
    // Internal AudioNodeStreams can only pass their output to another
    // AudioNode, whereas external AudioNodeStreams can pass their output
    // to other ProcessedMediaStreams or hardware audio output.
    EXTERNAL_OUTPUT = 1U << 2,
  };
  /**
   * Create a stream that will process audio for an AudioNode.
   * Takes ownership of aEngine.
   * aGraph is required and equals the graph of aCtx in most cases. An exception
   * is AudioDestinationNode where the context's graph hasn't been set up yet.
   */
  static already_AddRefed<AudioNodeStream>
  Create(AudioContext* aCtx, AudioNodeEngine* aEngine, Flags aKind,
         MediaStreamGraph* aGraph);

protected:
  /**
   * Transfers ownership of aEngine to the new AudioNodeStream.
   */
  AudioNodeStream(AudioNodeEngine* aEngine,
                  Flags aFlags,
                  TrackRate aSampleRate);

  ~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 SetThreeDPointParameter(uint32_t aIndex, const dom::ThreeDPoint& aValue);
  void SetBuffer(already_AddRefed<ThreadSharedFloatArrayBufferList>&& aBuffer);
  // This sends a single event to the timeline on the MSG thread side.
  void SendTimelineEvent(uint32_t aIndex, const dom::AudioTimelineEvent& aEvent);
  // 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;
  }

  /*
   * Resume stream after updating its concept of current time by aAdvance.
   * Main thread.  Used only from AudioDestinationNode when resuming a stream
   * suspended to save running the MediaStreamGraph when there are no other
   * nodes in the AudioContext.
   */
  void AdvanceAndResume(StreamTime aAdvance);

  AudioNodeStream* AsAudioNodeStream() override { return this; }
  void AddInput(MediaInputPort* aPort) override;
  void RemoveInput(MediaInputPort* aPort) override;

  // Graph thread only
  void SetStreamTimeParameterImpl(uint32_t aIndex, MediaStream* aRelativeToStream,
                                  double aStreamTime);
  void SetChannelMixingParametersImpl(uint32_t aNumberOfChannels,
                                      ChannelCountMode aChannelCountMoe,
                                      ChannelInterpretation aChannelInterpretation);
  void ProcessInput(GraphTime aFrom, GraphTime aTo, uint32_t aFlags) 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);
  bool IsAudioParamStream() const
  {
    return mAudioParamStream;
  }

  const OutputChunks& LastChunks() const
  {
    return mLastChunks;
  }
  bool MainThreadNeedsUpdates() const override
  {
    return ((mFlags & NEED_MAIN_THREAD_FINISHED) && mFinished) ||
      (mFlags & NEED_MAIN_THREAD_CURRENT_TIME);
  }

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

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

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

  /*
   * SetActive() is called when either an active input is added or the engine
   * for a source node transitions from inactive to active.  This is not
   * called from engines for processing nodes because they only become active
   * when there are active input streams, in which case this stream is already
   * active.
   */
  void SetActive();
  /*
   * ScheduleCheckForInactive() is called during stream processing when the
   * engine transitions from active to inactive, or the stream finishes.  It
   * schedules a call to CheckForInactive() after stream processing.
   */
  void ScheduleCheckForInactive();

protected:
  class AdvanceAndResumeMessage;
  class CheckForInactiveMessage;

  void DestroyImpl() override;

  /*
   * CheckForInactive() is called when the engine transitions from active to
   * inactive, or an active input is removed, or the stream finishes.  If the
   * stream is now inactive, then mInputChunks will be cleared and mLastChunks
   * will be set to null.  ProcessBlock() will not be called on the engine
   * again until SetActive() is called.
   */
  void CheckForInactive();

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

  uint32_t ComputedNumberOfChannels(uint32_t aInputChannelCount);
  void ObtainInputBlock(AudioBlock& aTmpChunk, uint32_t aPortIndex);
  void IncrementActiveInputCount();
  void DecrementActiveInputCount();

  // The engine that will generate output for this node.
  nsAutoPtr<AudioNodeEngine> mEngine;
  // The mixed input blocks are kept from iteration to iteration to avoid
  // reallocating channel data arrays and any buffers for mixing.
  OutputChunks mInputChunks;
  // 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
  const Flags mFlags;
  // The number of input streams that may provide non-silent input.
  uint32_t mActiveInputCount = 0;
  // The number of input channels that this stream requires. 0 means don't care.
  uint32_t mNumberOfInputChannels;
  // The mixing modes
  ChannelCountMode mChannelCountMode;
  ChannelInterpretation mChannelInterpretation;
  // Streams are considered active if the stream has not finished and either
  // the engine is active or there are active input streams.
  bool mIsActive;
  // 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;
};

} // namespace mozilla

#endif /* MOZILLA_AUDIONODESTREAM_H_ */