author alwu <>
Fri, 11 Jan 2019 20:43:01 +0000
changeset 453532 c34e287f2f7c
parent 452368 6a89226d8c15
child 457646 a04946ac4b3c
permissions -rw-r--r--
Bug 1513733 - part2 : try to start AudioContext when media element which is as a source for web audio starts r=cpearce,karlt If media element is used as a source for AudioContext, we would try to start AudioContext which was not allowed to start when media element starts playing. Differential Revision:

/* -*- 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 */

#ifndef MediaStreamAudioSourceNode_h_
#define MediaStreamAudioSourceNode_h_

#include "AudioNode.h"
#include "DOMMediaStream.h"
#include "AudioNodeEngine.h"

namespace mozilla {

namespace dom {

class AudioContext;
struct MediaStreamAudioSourceOptions;

class MediaStreamAudioSourceNodeEngine final : public AudioNodeEngine {
  explicit MediaStreamAudioSourceNodeEngine(AudioNode* aNode)
      : AudioNodeEngine(aNode), mEnabled(false) {}

  bool IsEnabled() const { return mEnabled; }
  enum Parameters { ENABLE };
  void SetInt32Parameter(uint32_t aIndex, int32_t aValue) override {
    switch (aIndex) {
      case ENABLE:
        mEnabled = !!aValue;
        NS_ERROR("MediaStreamAudioSourceNodeEngine bad parameter index");

  bool mEnabled;

class MediaStreamAudioSourceNode
    : public AudioNode,
      public DOMMediaStream::TrackListener,
      public PrincipalChangeObserver<MediaStreamTrack> {
  static already_AddRefed<MediaStreamAudioSourceNode> Create(
      AudioContext& aContext, const MediaStreamAudioSourceOptions& aOptions,
      ErrorResult& aRv);


  static already_AddRefed<MediaStreamAudioSourceNode> Constructor(
      const GlobalObject& aGlobal, AudioContext& aAudioContext,
      const MediaStreamAudioSourceOptions& aOptions, ErrorResult& aRv) {
    return Create(aAudioContext, aOptions, aRv);

  JSObject* WrapObject(JSContext* aCx,
                       JS::Handle<JSObject*> aGivenProto) override;

  void DestroyMediaStream() override;

  uint16_t NumberOfInputs() const override { return 0; }

  const char* NodeType() const override { return "MediaStreamAudioSourceNode"; }

  virtual const char* CrossOriginErrorString() const {
    return "MediaStreamAudioSourceNodeCrossOrigin";

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

  // Attaches to aTrack so that its audio content will be used as input.
  void AttachToTrack(const RefPtr<MediaStreamTrack>& aTrack);

  // Detaches from the currently attached track if there is one.
  void DetachFromTrack();

  // Attaches to the first available audio track in aMediaStream.
  void AttachToFirstTrack(const RefPtr<DOMMediaStream>& aMediaStream);

  // From DOMMediaStream::TrackListener.
  void NotifyTrackAdded(const RefPtr<MediaStreamTrack>& aTrack) override;
  void NotifyTrackRemoved(const RefPtr<MediaStreamTrack>& aTrack) override;

  // From PrincipalChangeObserver<MediaStreamTrack>.
  void PrincipalChanged(MediaStreamTrack* aMediaStreamTrack) override;

  explicit MediaStreamAudioSourceNode(AudioContext* aContext);
  void Init(DOMMediaStream* aMediaStream, ErrorResult& aRv);
  virtual void Destroy();
  virtual ~MediaStreamAudioSourceNode();

  RefPtr<MediaInputPort> mInputPort;
  RefPtr<DOMMediaStream> mInputStream;

  // On construction we set this to the first audio track of mInputStream.
  RefPtr<MediaStreamTrack> mInputTrack;

}  // namespace dom
}  // namespace mozilla