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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=2 et sw=2 tw=80: */
/* 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 DOM_MEDIA_AudioInputSource_H_
#define DOM_MEDIA_AudioInputSource_H_
#include "AudioDriftCorrection.h"
#include "AudioSegment.h"
#include "CubebInputStream.h"
#include "CubebUtils.h"
#include "mozilla/ProfilerUtils.h"
#include "mozilla/RefPtr.h"
#include "mozilla/SPSCQueue.h"
#include "mozilla/SharedThreadPool.h"
namespace mozilla {
// This is an interface to operate an input-only audio stream within a
// cubeb-task thread on a specific thread. Once the class instance is created,
// all its operations must be called on the same thread.
// The audio data is periodically produced by the underlying audio stream on the
// stream's callback thread, and can be safely read by GetAudioSegment() on a
// specific thread.
class AudioInputSource : public CubebInputStream::Listener {
using Id = uint32_t;
class EventListener {
// This two events will be fired on main thread.
virtual void AudioDeviceChanged(Id aId) = 0;
enum class State { Started, Stopped, Drained, Error };
virtual void AudioStateCallback(Id aId, State aState) = 0;
EventListener() = default;
virtual ~EventListener() = default;
AudioInputSource(RefPtr<EventListener>&& aListener, Id aSourceId,
CubebUtils::AudioDeviceID aDeviceId, uint32_t aChannelCount,
bool aIsVoice, const PrincipalHandle& aPrincipalHandle,
TrackRate aSourceRate, TrackRate aTargetRate,
uint32_t aBufferMs);
// The following functions should always be called in the same thread: They
// are always run on MediaTrackGraph's graph thread.
// Starts producing audio data.
void Start();
// Stops producing audio data.
void Stop();
// Returns the AudioSegment with aDuration of data inside.
// The graph thread can change behind the scene, e.g., cubeb stream reinit due
// to default output device changed). When this happens, we need to notify
// mSPSCQueue to change its data consumer.
enum class Consumer { Same, Changed };
AudioSegment GetAudioSegment(TrackTime aDuration, Consumer aConsumer);
// CubebInputStream::Listener interface: These are used only for the
// underlying audio stream. No user should call these APIs.
// This will be fired on audio callback thread.
long DataCallback(const void* aBuffer, long aFrames) override;
// This can be fired on any thread.
void StateCallback(cubeb_state aState) override;
// This can be fired on any thread.
void DeviceChangedCallback() override;
// Any threads:
// The unique id of this source.
const Id mId;
// The id of this audio device producing the data.
const CubebUtils::AudioDeviceID mDeviceId;
// The channel count of audio data produced.
const uint32_t mChannelCount;
// The sample rate of the audio data produced.
const TrackRate mRate;
// Indicate whether the audio stream is for voice or not.
const bool mIsVoice;
// The principal of the audio data produced.
const PrincipalHandle mPrincipalHandle;
~AudioInputSource() = default;
// Underlying audio thread only.
bool CheckThreadIdChanged();
// Any thread.
const bool mSandboxed;
// Thread id of the underlying audio thread. Underlying audio thread only.
std::atomic<ProfilerThreadId> mAudioThreadId;
// Forward the underlying event from main thread.
const RefPtr<EventListener> mEventListener;
// Shared thread pool containing only one thread for cubeb operations.
// The cubeb operations: Start() and Stop() will be called on
// MediaTrackGraph's graph thread, which can be the cubeb stream's callback
// thread. Running cubeb operations within cubeb stream callback thread can
// cause the deadlock on Linux, so we dispatch those operations to the task
// thread.
const RefPtr<SharedThreadPool> mTaskThread;
// Correct the drift between the underlying audio stream and its reader.
AudioDriftCorrection mDriftCorrector;
// An input-only cubeb stream operated within mTaskThread.
UniquePtr<CubebInputStream> mStream;
// A single-producer-single-consumer lock-free queue whose data is produced by
// the audio callback thread and consumed by AudioInputSource's data reader.
SPSCQueue<AudioChunk> mSPSCQueue{30};
} // namespace mozilla
#endif // DOM_MEDIA_AudioInputSource_H_