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/* -*- 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 AudioDestinationNode_h_
#define AudioDestinationNode_h_
#include "AudioChannelService.h"
#include "AudioNode.h"
#include "AudioChannelAgent.h"
#include "mozilla/TimeStamp.h"
namespace mozilla::dom {
class AudioContext;
class WakeLock;
class AudioDestinationNode final : public AudioNode,
public nsIAudioChannelAgentCallback,
public MainThreadMediaTrackListener {
// This node type knows what MediaTrackGraph to use based on
// whether it's in offline mode.
AudioDestinationNode(AudioContext* aContext, bool aIsOffline,
uint32_t aNumberOfChannels, uint32_t aLength);
void DestroyMediaTrack() override;
JSObject* WrapObject(JSContext* aCx,
JS::Handle<JSObject*> aGivenProto) override;
uint16_t NumberOfOutputs() const final { return 0; }
uint32_t MaxChannelCount() const;
void SetChannelCount(uint32_t aChannelCount, ErrorResult& aRv) override;
void Init();
void Close();
// Returns the track or null after unlink.
AudioNodeTrack* Track();
void Mute();
void Unmute();
void Suspend();
void Resume();
void StartRendering(Promise* aPromise);
void OfflineShutdown();
void NotifyMainThreadTrackEnded() override;
void FireOfflineCompletionEvent();
const char* NodeType() const override { return "AudioDestinationNode"; }
size_t SizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const override;
size_t SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const override;
void NotifyDataAudibleStateChanged(bool aAudible);
void ResolvePromise(AudioBuffer* aRenderedBuffer);
unsigned long Length() {
return mFramesToProduce;
void NotifyAudioContextStateChanged();
virtual ~AudioDestinationNode();
// This would be created for non-offline audio context in order to receive
// tab's mute/suspend/audio capture state change and update the audible state
// to the tab.
void CreateAndStartAudioChannelAgent();
void DestroyAudioChannelAgentIfExists();
RefPtr<AudioChannelAgent> mAudioChannelAgent;
// These members are related to audio capturing. We would start capturing
// audio if we're starting capturing audio from whole window, and MUST stop
// capturing explicitly when we don't need to capture audio any more, because
// we have to release the resource we allocated before.
bool IsCapturingAudio() const;
void StartAudioCapturingTrack();
void StopAudioCapturingTrack();
RefPtr<MediaInputPort> mCaptureTrackPort;
// These members are used to determine if the destination node is actual
// audible and `mFinalAudibleState` represents the final result.
using AudibleChangedReasons = AudioChannelService::AudibleChangedReasons;
using AudibleState = AudioChannelService::AudibleState;
void UpdateFinalAudibleStateIfNeeded(AudibleChangedReasons aReason);
bool IsAudible() const;
bool mFinalAudibleState = false;
bool mIsDataAudible = false;
float mAudioChannelVolume = 1.0;
// True if the audio channel disables the track for unvisited tab, and the
// track will be enabled again when the tab gets first visited, or a user
// presses the tab play icon.
bool mAudioChannelDisabled = false;
// When the destination node is audible, we would request a wakelock to
// prevent computer from sleeping in order to keep audio playing.
void CreateAudioWakeLockIfNeeded();
void ReleaseAudioWakeLockIfExists();
RefPtr<WakeLock> mWakeLock;
SelfReference<AudioDestinationNode> mOfflineRenderingRef;
uint32_t mFramesToProduce;
RefPtr<Promise> mOfflineRenderingPromise;
bool mIsOffline;
// These varaibles are used to know how long AudioContext would become audible
// since it was created.
TimeStamp mCreatedTime;
TimeDuration mDurationBeforeFirstTimeAudible;
} // namespace mozilla::dom