gecko-dev/dom/media/GraphDriver.cpp

1301 строка
45 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=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 http://mozilla.org/MPL/2.0/. */
#include "GraphDriver.h"
#include "AudioNodeEngine.h"
#include "mozilla/dom/AudioContext.h"
#include "mozilla/dom/AudioDeviceInfo.h"
#include "mozilla/dom/BaseAudioContextBinding.h"
#include "mozilla/SchedulerGroup.h"
#include "mozilla/SharedThreadPool.h"
#include "mozilla/ClearOnShutdown.h"
#include "mozilla/Unused.h"
#include "mozilla/MathAlgorithms.h"
#include "CubebDeviceEnumerator.h"
#include "MediaTrackGraphImpl.h"
#include "AudioThreadRegistry.h"
#include "Tracing.h"
#ifdef MOZ_WEBRTC
# include "webrtc/MediaEngineWebRTC.h"
#endif
#ifdef XP_MACOSX
# include <sys/sysctl.h>
#endif
extern mozilla::LazyLogModule gMediaTrackGraphLog;
#ifdef LOG
# undef LOG
#endif // LOG
#define LOG(type, msg) MOZ_LOG(gMediaTrackGraphLog, type, msg)
namespace mozilla {
GraphDriver::GraphDriver(GraphInterface* aGraphInterface,
GraphDriver* aPreviousDriver, uint32_t aSampleRate)
: mGraphInterface(aGraphInterface),
mSampleRate(aSampleRate),
mPreviousDriver(aPreviousDriver) {}
void GraphDriver::SetState(GraphTime aIterationStart, GraphTime aIterationEnd,
GraphTime aStateComputedTime) {
MOZ_ASSERT(InIteration() || !ThreadRunning());
mIterationStart = aIterationStart;
mIterationEnd = aIterationEnd;
mStateComputedTime = aStateComputedTime;
}
#ifdef DEBUG
bool GraphDriver::InIteration() {
return OnThread() || Graph()->InDriverIteration(this);
}
#endif
GraphDriver* GraphDriver::PreviousDriver() {
MOZ_ASSERT(InIteration() || !ThreadRunning());
return mPreviousDriver;
}
void GraphDriver::SetPreviousDriver(GraphDriver* aPreviousDriver) {
MOZ_ASSERT(InIteration() || !ThreadRunning());
mPreviousDriver = aPreviousDriver;
}
ThreadedDriver::ThreadedDriver(GraphInterface* aGraphInterface,
GraphDriver* aPreviousDriver,
uint32_t aSampleRate)
: GraphDriver(aGraphInterface, aPreviousDriver, aSampleRate),
mThreadRunning(false) {}
class MediaTrackGraphShutdownThreadRunnable : public Runnable {
public:
explicit MediaTrackGraphShutdownThreadRunnable(
already_AddRefed<nsIThread> aThread)
: Runnable("MediaTrackGraphShutdownThreadRunnable"), mThread(aThread) {}
NS_IMETHOD Run() override {
MOZ_ASSERT(NS_IsMainThread());
MOZ_ASSERT(mThread);
mThread->Shutdown();
mThread = nullptr;
return NS_OK;
}
private:
nsCOMPtr<nsIThread> mThread;
};
ThreadedDriver::~ThreadedDriver() {
if (mThread) {
nsCOMPtr<nsIRunnable> event =
new MediaTrackGraphShutdownThreadRunnable(mThread.forget());
SchedulerGroup::Dispatch(TaskCategory::Other, event.forget());
}
}
class MediaTrackGraphInitThreadRunnable : public Runnable {
public:
explicit MediaTrackGraphInitThreadRunnable(ThreadedDriver* aDriver)
: Runnable("MediaTrackGraphInitThreadRunnable"), mDriver(aDriver) {}
NS_IMETHOD Run() override {
MOZ_ASSERT(!mDriver->ThreadRunning());
LOG(LogLevel::Debug, ("Starting a new system driver for graph %p",
mDriver->mGraphInterface.get()));
if (GraphDriver* previousDriver = mDriver->PreviousDriver()) {
LOG(LogLevel::Debug,
("%p releasing an AudioCallbackDriver(%p), for graph %p",
mDriver.get(), previousDriver, mDriver->Graph()));
MOZ_ASSERT(!mDriver->AsAudioCallbackDriver());
RefPtr<AsyncCubebTask> releaseEvent =
new AsyncCubebTask(previousDriver->AsAudioCallbackDriver(),
AsyncCubebOperation::SHUTDOWN);
releaseEvent->Dispatch();
mDriver->SetPreviousDriver(nullptr);
}
mDriver->RunThread();
return NS_OK;
}
private:
RefPtr<ThreadedDriver> mDriver;
};
void ThreadedDriver::Start() {
MOZ_ASSERT(!ThreadRunning());
LOG(LogLevel::Debug,
("Starting thread for a SystemClockDriver %p", mGraphInterface.get()));
Unused << NS_WARN_IF(mThread);
MOZ_ASSERT(!mThread); // Ensure we haven't already started it
nsCOMPtr<nsIRunnable> event = new MediaTrackGraphInitThreadRunnable(this);
// Note: mThread may be null during event->Run() if we pass to NewNamedThread!
// See AudioInitTask
nsresult rv = NS_NewNamedThread("MediaTrackGrph", getter_AddRefs(mThread));
if (NS_SUCCEEDED(rv)) {
mThread->EventTarget()->Dispatch(event.forget(), NS_DISPATCH_NORMAL);
}
}
void ThreadedDriver::Shutdown() {
NS_ASSERTION(NS_IsMainThread(), "Must be called on main thread");
// mGraph's thread is not running so it's OK to do whatever here
LOG(LogLevel::Debug, ("Stopping threads for MediaTrackGraph %p", this));
if (mThread) {
LOG(LogLevel::Debug,
("%p: Stopping ThreadedDriver's %p thread", Graph(), this));
mThread->Shutdown();
mThread = nullptr;
}
}
SystemClockDriver::SystemClockDriver(GraphInterface* aGraphInterface,
GraphDriver* aPreviousDriver,
uint32_t aSampleRate)
: ThreadedDriver(aGraphInterface, aPreviousDriver, aSampleRate),
mInitialTimeStamp(TimeStamp::Now()),
mCurrentTimeStamp(TimeStamp::Now()),
mLastTimeStamp(TimeStamp::Now()) {}
SystemClockDriver::~SystemClockDriver() = default;
void ThreadedDriver::RunThread() {
mThreadRunning = true;
while (true) {
mIterationStart = mIterationEnd;
mIterationEnd += GetIntervalForIteration();
if (mStateComputedTime < mIterationEnd) {
LOG(LogLevel::Warning, ("%p: Global underrun detected", Graph()));
mIterationEnd = mStateComputedTime;
}
if (mIterationStart >= mIterationEnd) {
NS_ASSERTION(mIterationStart == mIterationEnd,
"Time can't go backwards!");
// This could happen due to low clock resolution, maybe?
LOG(LogLevel::Debug, ("%p: Time did not advance", Graph()));
}
GraphTime nextStateComputedTime =
MediaTrackGraphImpl::RoundUpToEndOfAudioBlock(
mIterationEnd + MillisecondsToMediaTime(AUDIO_TARGET_MS));
if (nextStateComputedTime < mStateComputedTime) {
// A previous driver may have been processing further ahead of
// iterationEnd.
LOG(LogLevel::Warning,
("%p: Prevent state from going backwards. interval[%ld; %ld] "
"state[%ld; "
"%ld]",
Graph(), (long)mIterationStart, (long)mIterationEnd,
(long)mStateComputedTime, (long)nextStateComputedTime));
nextStateComputedTime = mStateComputedTime;
}
LOG(LogLevel::Verbose,
("%p: interval[%ld; %ld] state[%ld; %ld]", Graph(),
(long)mIterationStart, (long)mIterationEnd, (long)mStateComputedTime,
(long)nextStateComputedTime));
mStateComputedTime = nextStateComputedTime;
IterationResult result =
Graph()->OneIteration(mStateComputedTime, mIterationEnd, nullptr);
if (result.IsStop()) {
// Signal that we're done stopping.
result.Stopped();
break;
}
WaitForNextIteration();
if (GraphDriver* nextDriver = result.NextDriver()) {
LOG(LogLevel::Debug, ("%p: Switching to AudioCallbackDriver", Graph()));
result.Switched();
nextDriver->SetState(mIterationStart, mIterationEnd, mStateComputedTime);
nextDriver->Start();
break;
}
MOZ_ASSERT(result.IsStillProcessing());
}
mThreadRunning = false;
}
MediaTime SystemClockDriver::GetIntervalForIteration() {
TimeStamp now = TimeStamp::Now();
MediaTime interval =
SecondsToMediaTime((now - mCurrentTimeStamp).ToSeconds());
mCurrentTimeStamp = now;
MOZ_LOG(gMediaTrackGraphLog, LogLevel::Verbose,
("%p: Updating current time to %f (real %f, StateComputedTime() %f)",
Graph(), MediaTimeToSeconds(mIterationEnd + interval),
(now - mInitialTimeStamp).ToSeconds(),
MediaTimeToSeconds(mStateComputedTime)));
return interval;
}
void ThreadedDriver::EnsureNextIteration() {
mWaitHelper.EnsureNextIteration();
}
void ThreadedDriver::WaitForNextIteration() {
MOZ_ASSERT(mThread);
MOZ_ASSERT(OnThread());
mWaitHelper.WaitForNextIterationAtLeast(WaitInterval());
}
TimeDuration SystemClockDriver::WaitInterval() {
MOZ_ASSERT(mThread);
MOZ_ASSERT(OnThread());
TimeStamp now = TimeStamp::Now();
int64_t timeoutMS = MEDIA_GRAPH_TARGET_PERIOD_MS -
int64_t((now - mCurrentTimeStamp).ToMilliseconds());
// Make sure timeoutMS doesn't overflow 32 bits by waking up at
// least once a minute, if we need to wake up at all
timeoutMS = std::max<int64_t>(0, std::min<int64_t>(timeoutMS, 60 * 1000));
LOG(LogLevel::Verbose,
("%p: Waiting for next iteration; at %f, timeout=%f", Graph(),
(now - mInitialTimeStamp).ToSeconds(), timeoutMS / 1000.0));
return TimeDuration::FromMilliseconds(timeoutMS);
}
OfflineClockDriver::OfflineClockDriver(GraphInterface* aGraphInterface,
uint32_t aSampleRate, GraphTime aSlice)
: ThreadedDriver(aGraphInterface, nullptr, aSampleRate), mSlice(aSlice) {}
OfflineClockDriver::~OfflineClockDriver() = default;
void OfflineClockDriver::RunThread() {
nsCOMPtr<nsIThreadInternal> threadInternal = do_QueryInterface(mThread);
nsCOMPtr<nsIThreadObserver> observer = do_QueryInterface(Graph());
threadInternal->SetObserver(observer);
ThreadedDriver::RunThread();
}
MediaTime OfflineClockDriver::GetIntervalForIteration() {
return MillisecondsToMediaTime(mSlice);
}
AsyncCubebTask::AsyncCubebTask(AudioCallbackDriver* aDriver,
AsyncCubebOperation aOperation)
: Runnable("AsyncCubebTask"),
mDriver(aDriver),
mOperation(aOperation),
mShutdownGrip(aDriver->Graph()) {
NS_WARNING_ASSERTION(
mDriver->mAudioStream || aOperation == AsyncCubebOperation::INIT,
"No audio stream!");
}
AsyncCubebTask::~AsyncCubebTask() = default;
NS_IMETHODIMP
AsyncCubebTask::Run() {
MOZ_ASSERT(mDriver);
switch (mOperation) {
case AsyncCubebOperation::INIT: {
LOG(LogLevel::Debug, ("%p: AsyncCubebOperation::INIT driver=%p",
mDriver->Graph(), mDriver.get()));
mDriver->Init();
break;
}
case AsyncCubebOperation::SHUTDOWN: {
LOG(LogLevel::Debug, ("%p: AsyncCubebOperation::SHUTDOWN driver=%p",
mDriver->Graph(), mDriver.get()));
mDriver->Stop();
mDriver = nullptr;
mShutdownGrip = nullptr;
break;
}
default:
MOZ_CRASH("Operation not implemented.");
}
// The thread will kill itself after a bit
return NS_OK;
}
TrackAndPromiseForOperation::TrackAndPromiseForOperation(
MediaTrack* aTrack, dom::AudioContextOperation aOperation,
AbstractThread* aMainThread,
MozPromiseHolder<MediaTrackGraph::AudioContextOperationPromise>&& aHolder)
: mTrack(aTrack),
mOperation(aOperation),
mMainThread(aMainThread),
mHolder(std::move(aHolder)) {}
TrackAndPromiseForOperation::TrackAndPromiseForOperation(
TrackAndPromiseForOperation&& aOther) noexcept
: mTrack(std::move(aOther.mTrack)),
mOperation(aOther.mOperation),
mMainThread(std::move(aOther.mMainThread)),
mHolder(std::move(aOther.mHolder)) {}
/* Helper to proxy the GraphInterface methods used by a running
* mFallbackDriver. */
class AudioCallbackDriver::FallbackWrapper : public GraphInterface {
public:
FallbackWrapper(RefPtr<GraphInterface> aGraph,
RefPtr<AudioCallbackDriver> aOwner, uint32_t aSampleRate,
GraphTime aIterationStart, GraphTime aIterationEnd,
GraphTime aStateComputedTime)
: mGraph(std::move(aGraph)),
mOwner(std::move(aOwner)),
mFallbackDriver(
MakeRefPtr<SystemClockDriver>(this, nullptr, aSampleRate)),
mIterationStart(aIterationStart),
mIterationEnd(aIterationEnd),
mStateComputedTime(aStateComputedTime) {
mFallbackDriver->SetState(mIterationStart, mIterationEnd,
mStateComputedTime);
}
NS_DECL_THREADSAFE_ISUPPORTS
/* Proxied SystemClockDriver methods */
void SetState(GraphTime aIterationStart, GraphTime aIterationEnd,
GraphTime aStateComputedTime) {
mIterationStart = aIterationStart;
mIterationEnd = aIterationEnd;
mStateComputedTime = aStateComputedTime;
mFallbackDriver->SetState(aIterationStart, aIterationEnd,
aStateComputedTime);
}
void Start() { mFallbackDriver->Start(); }
MOZ_CAN_RUN_SCRIPT void Shutdown() {
RefPtr<SystemClockDriver> driver = mFallbackDriver;
driver->Shutdown();
}
void EnsureNextIteration() { mFallbackDriver->EnsureNextIteration(); }
#ifdef DEBUG
bool InIteration() { return mFallbackDriver->InIteration(); }
#endif
bool OnThread() { return mFallbackDriver->OnThread(); }
/* GraphInterface methods */
void NotifyOutputData(AudioDataValue* aBuffer, size_t aFrames,
TrackRate aRate, uint32_t aChannels) override {
MOZ_CRASH("Unexpected NotifyOutputData from fallback SystemClockDriver");
}
void NotifyStarted() override {
MOZ_CRASH("Unexpected NotifyStarted from fallback SystemClockDriver");
}
void NotifyInputData(const AudioDataValue* aBuffer, size_t aFrames,
TrackRate aRate, uint32_t aChannels) override {
MOZ_CRASH("Unexpected NotifyInputData from fallback SystemClockDriver");
}
void DeviceChanged() override {
MOZ_CRASH("Unexpected DeviceChanged from fallback SystemClockDriver");
}
#ifdef DEBUG
bool InDriverIteration(GraphDriver* aDriver) override {
return !mOwner->ThreadRunning() && mOwner->InIteration();
}
#endif
IterationResult OneIteration(GraphTime aStateComputedEnd,
GraphTime aIterationEnd,
AudioMixer* aMixer) override {
MOZ_ASSERT(!aMixer);
#ifdef DEBUG
AutoInCallback aic(mOwner);
#endif
mIterationStart = mIterationEnd;
mIterationEnd = aIterationEnd;
mStateComputedTime = aStateComputedEnd;
IterationResult result =
mGraph->OneIteration(aStateComputedEnd, aIterationEnd, aMixer);
AudioStreamState audioState = mOwner->mAudioStreamState;
MOZ_ASSERT(audioState != AudioStreamState::Stopping,
"The audio driver can only enter stopping if it iterated the "
"graph, which it can only do if there's no fallback driver");
if (audioState != AudioStreamState::Running && result.IsStillProcessing()) {
if (audioState != AudioStreamState::Errored) {
mOwner->MaybeStartAudioStream();
}
return result;
}
MOZ_ASSERT(result.IsStillProcessing() || result.IsStop() ||
result.IsSwitchDriver());
// Proxy the release of the fallback driver to a background thread, so it
// doesn't perform unexpected suicide.
IterationResult stopFallback =
IterationResult::CreateStop(NS_NewRunnableFunction(
"AudioCallbackDriver::FallbackDriverStopped",
[self = RefPtr<FallbackWrapper>(this), this,
result = std::move(result)]() mutable {
FallbackDriverState fallbackState =
result.IsStillProcessing() ? FallbackDriverState::None
: FallbackDriverState::Stopped;
mOwner->FallbackDriverStopped(mIterationStart, mIterationEnd,
mStateComputedTime, fallbackState);
if (fallbackState == FallbackDriverState::Stopped) {
#ifdef DEBUG
// The AudioCallbackDriver may not iterate the graph, but we'll
// call into it so we need to be regarded as "in iteration".
AutoInCallback aic(mOwner);
#endif
if (GraphDriver* nextDriver = result.NextDriver()) {
LOG(LogLevel::Debug,
("%p: Switching from fallback to other driver.",
mGraph.get()));
result.Switched();
nextDriver->SetState(mIterationStart, mIterationEnd,
mStateComputedTime);
nextDriver->Start();
} else if (result.IsStop()) {
LOG(LogLevel::Debug,
("%p: Stopping fallback driver.", mGraph.get()));
result.Stopped();
}
}
mOwner = nullptr;
NS_DispatchBackgroundTask(NS_NewRunnableFunction(
"AudioCallbackDriver::FallbackDriverStopped::Release",
[fallback = std::move(self->mFallbackDriver)] {}));
}));
return stopFallback;
}
private:
virtual ~FallbackWrapper() = default;
const RefPtr<GraphInterface> mGraph;
// Valid until mFallbackDriver has finished its last iteration.
RefPtr<AudioCallbackDriver> mOwner;
RefPtr<SystemClockDriver> mFallbackDriver;
GraphTime mIterationStart;
GraphTime mIterationEnd;
GraphTime mStateComputedTime;
};
NS_IMPL_ISUPPORTS0(AudioCallbackDriver::FallbackWrapper)
AudioCallbackDriver::AudioCallbackDriver(
GraphInterface* aGraphInterface, GraphDriver* aPreviousDriver,
uint32_t aSampleRate, uint32_t aOutputChannelCount,
uint32_t aInputChannelCount, CubebUtils::AudioDeviceID aOutputDeviceID,
CubebUtils::AudioDeviceID aInputDeviceID, AudioInputType aAudioInputType)
: GraphDriver(aGraphInterface, aPreviousDriver, aSampleRate),
mOutputChannelCount(aOutputChannelCount),
mInputChannelCount(aInputChannelCount),
mOutputDeviceID(aOutputDeviceID),
mInputDeviceID(aInputDeviceID),
mIterationDurationMS(MEDIA_GRAPH_TARGET_PERIOD_MS),
mStarted(false),
mInitShutdownThread(
SharedThreadPool::Get(NS_LITERAL_CSTRING("CubebOperation"), 1)),
mAudioThreadId(0),
mAudioThreadIdInCb(std::thread::id()),
mAudioStreamState(AudioStreamState::None),
mFallback("AudioCallbackDriver::mFallback"),
mSandboxed(CubebUtils::SandboxEnabled()) {
LOG(LogLevel::Debug, ("%p: AudioCallbackDriver ctor", Graph()));
NS_WARNING_ASSERTION(mOutputChannelCount != 0,
"Invalid output channel count");
MOZ_ASSERT(mOutputChannelCount <= 8);
const uint32_t kIdleThreadTimeoutMs = 2000;
mInitShutdownThread->SetIdleThreadTimeout(
PR_MillisecondsToInterval(kIdleThreadTimeoutMs));
#if defined(XP_WIN)
if (XRE_IsContentProcess()) {
audio::AudioNotificationReceiver::Register(this);
}
#endif
if (aAudioInputType == AudioInputType::Voice) {
LOG(LogLevel::Debug, ("VOICE."));
mInputDevicePreference = CUBEB_DEVICE_PREF_VOICE;
CubebUtils::SetInCommunication(true);
} else {
mInputDevicePreference = CUBEB_DEVICE_PREF_ALL;
}
mMixer.AddCallback(WrapNotNull(this));
}
AudioCallbackDriver::~AudioCallbackDriver() {
#if defined(XP_WIN)
if (XRE_IsContentProcess()) {
audio::AudioNotificationReceiver::Unregister(this);
}
#endif
if (mInputDevicePreference == CUBEB_DEVICE_PREF_VOICE) {
CubebUtils::SetInCommunication(false);
}
}
bool IsMacbookOrMacbookAir() {
#ifdef XP_MACOSX
size_t len = 0;
sysctlbyname("hw.model", NULL, &len, NULL, 0);
if (len) {
UniquePtr<char[]> model(new char[len]);
// This string can be
// MacBook%d,%d for a normal MacBook
// MacBookPro%d,%d for a MacBook Pro
// MacBookAir%d,%d for a Macbook Air
sysctlbyname("hw.model", model.get(), &len, NULL, 0);
char* substring = strstr(model.get(), "MacBook");
if (substring) {
const size_t offset = strlen("MacBook");
if (!strncmp(model.get() + offset, "Air", 3) ||
isdigit(model[offset + 1])) {
return true;
}
}
}
#endif
return false;
}
void AudioCallbackDriver::Init() {
AUTO_PROFILER_LABEL("AudioCallbackDriver::Init", MEDIA_CUBEB);
MOZ_ASSERT(OnCubebOperationThread());
MOZ_ASSERT(mAudioStreamState == AudioStreamState::Pending);
FallbackDriverState fallbackState = mFallbackDriverState;
if (fallbackState == FallbackDriverState::Stopped) {
// The graph has already stopped us.
return;
}
bool fromFallback = fallbackState == FallbackDriverState::Running;
cubeb* cubebContext = CubebUtils::GetCubebContext();
if (!cubebContext) {
NS_WARNING("Could not get cubeb context.");
LOG(LogLevel::Warning, ("%s: Could not get cubeb context", __func__));
mAudioStreamState = AudioStreamState::None;
if (!fromFallback) {
CubebUtils::ReportCubebStreamInitFailure(true);
FallbackToSystemClockDriver();
}
return;
}
cubeb_stream_params output;
cubeb_stream_params input;
bool firstStream = CubebUtils::GetFirstStream();
MOZ_ASSERT(!NS_IsMainThread(),
"This is blocking and should never run on the main thread.");
output.rate = mSampleRate;
if (AUDIO_OUTPUT_FORMAT == AUDIO_FORMAT_S16) {
output.format = CUBEB_SAMPLE_S16NE;
} else {
output.format = CUBEB_SAMPLE_FLOAT32NE;
}
if (!mOutputChannelCount) {
LOG(LogLevel::Warning, ("Output number of channels is 0."));
mAudioStreamState = AudioStreamState::None;
if (!fromFallback) {
CubebUtils::ReportCubebStreamInitFailure(firstStream);
FallbackToSystemClockDriver();
}
return;
}
CubebUtils::AudioDeviceID forcedOutputDeviceId = nullptr;
char* forcedOutputDeviceName = CubebUtils::GetForcedOutputDevice();
if (forcedOutputDeviceName) {
RefPtr<CubebDeviceEnumerator> enumerator = Enumerator::GetInstance();
RefPtr<AudioDeviceInfo> device = enumerator->DeviceInfoFromName(
NS_ConvertUTF8toUTF16(forcedOutputDeviceName), EnumeratorSide::OUTPUT);
if (device && device->DeviceID()) {
forcedOutputDeviceId = device->DeviceID();
}
}
mBuffer = AudioCallbackBufferWrapper<AudioDataValue>(mOutputChannelCount);
mScratchBuffer =
SpillBuffer<AudioDataValue, WEBAUDIO_BLOCK_SIZE * 2>(mOutputChannelCount);
output.channels = mOutputChannelCount;
AudioConfig::ChannelLayout::ChannelMap channelMap =
AudioConfig::ChannelLayout(mOutputChannelCount).Map();
output.layout = static_cast<uint32_t>(channelMap);
output.prefs = CubebUtils::GetDefaultStreamPrefs();
#if !defined(XP_WIN)
if (mInputDevicePreference == CUBEB_DEVICE_PREF_VOICE &&
CubebUtils::RouteOutputAsVoice()) {
output.prefs |= static_cast<cubeb_stream_prefs>(CUBEB_STREAM_PREF_VOICE);
}
#endif
uint32_t latencyFrames = CubebUtils::GetCubebMTGLatencyInFrames(&output);
// Macbook and MacBook air don't have enough CPU to run very low latency
// MediaTrackGraphs, cap the minimal latency to 512 frames int this case.
if (IsMacbookOrMacbookAir()) {
latencyFrames = std::max((uint32_t)512, latencyFrames);
}
// On OSX, having a latency that is lower than 10ms is very common. It's
// not very useful when doing voice, because all the WebRTC code deal in 10ms
// chunks of audio. Take the first power of two above 10ms at the current
// rate in this case. It's probably 512, for common rates.
#if defined(XP_MACOSX)
if (mInputDevicePreference == CUBEB_DEVICE_PREF_VOICE) {
if (latencyFrames < mSampleRate / 100) {
latencyFrames = mozilla::RoundUpPow2(mSampleRate / 100);
}
}
#endif
LOG(LogLevel::Debug, ("Effective latency in frames: %d", latencyFrames));
input = output;
input.channels = mInputChannelCount;
input.layout = CUBEB_LAYOUT_UNDEFINED;
input.prefs = CubebUtils::GetDefaultStreamPrefs();
if (mInputDevicePreference == CUBEB_DEVICE_PREF_VOICE) {
input.prefs |= static_cast<cubeb_stream_prefs>(CUBEB_STREAM_PREF_VOICE);
}
cubeb_stream* stream = nullptr;
bool inputWanted = mInputChannelCount > 0;
CubebUtils::AudioDeviceID outputId = mOutputDeviceID;
CubebUtils::AudioDeviceID inputId = mInputDeviceID;
// XXX Only pass input input if we have an input listener. Always
// set up output because it's easier, and it will just get silence.
if (cubeb_stream_init(cubebContext, &stream, "AudioCallbackDriver", inputId,
inputWanted ? &input : nullptr,
forcedOutputDeviceId ? forcedOutputDeviceId : outputId,
&output, latencyFrames, DataCallback_s, StateCallback_s,
this) == CUBEB_OK) {
mAudioStream.own(stream);
DebugOnly<int> rv =
cubeb_stream_set_volume(mAudioStream, CubebUtils::GetVolumeScale());
NS_WARNING_ASSERTION(
rv == CUBEB_OK,
"Could not set the audio stream volume in GraphDriver.cpp");
CubebUtils::ReportCubebBackendUsed();
} else {
NS_WARNING(
"Could not create a cubeb stream for MediaTrackGraph, falling "
"back to a SystemClockDriver");
mAudioStreamState = AudioStreamState::None;
// Only report failures when we're not coming from a driver that was
// created itself as a fallback driver because of a previous audio driver
// failure.
if (!fromFallback) {
CubebUtils::ReportCubebStreamInitFailure(firstStream);
FallbackToSystemClockDriver();
}
return;
}
#ifdef XP_MACOSX
PanOutputIfNeeded(inputWanted);
#endif
cubeb_stream_register_device_changed_callback(
mAudioStream, AudioCallbackDriver::DeviceChangedCallback_s);
// No-op if MOZ_DUMP_AUDIO is not defined as an environment variable. This
// is intended for diagnosing issues, and only works if the content sandbox is
// disabled.
mInputStreamFile.Open("GraphDriverInput", input.channels, input.rate);
mOutputStreamFile.Open("GraphDriverOutput", output.channels, output.rate);
if (NS_WARN_IF(!StartStream())) {
LOG(LogLevel::Warning,
("%p: AudioCallbackDriver couldn't start a cubeb stream.", Graph()));
return;
}
LOG(LogLevel::Debug, ("%p: AudioCallbackDriver started.", Graph()));
}
void AudioCallbackDriver::Start() {
MOZ_ASSERT(!IsStarted());
MOZ_ASSERT(mAudioStreamState == AudioStreamState::None);
MOZ_ASSERT_IF(PreviousDriver(), PreviousDriver()->InIteration());
mAudioStreamState = AudioStreamState::Pending;
mRanFirstIteration = false;
if (mFallbackDriverState == FallbackDriverState::None) {
// Starting an audio driver could take a while. We start a system driver in
// the meantime so that the graph is kept running.
FallbackToSystemClockDriver();
}
if (mPreviousDriver) {
if (mPreviousDriver->AsAudioCallbackDriver()) {
LOG(LogLevel::Debug, ("Releasing audio driver off main thread."));
RefPtr<AsyncCubebTask> releaseEvent =
new AsyncCubebTask(mPreviousDriver->AsAudioCallbackDriver(),
AsyncCubebOperation::SHUTDOWN);
releaseEvent->Dispatch();
} else {
LOG(LogLevel::Debug,
("Dropping driver reference for SystemClockDriver."));
MOZ_ASSERT(mPreviousDriver->AsSystemClockDriver());
}
mPreviousDriver = nullptr;
}
LOG(LogLevel::Debug, ("Starting new audio driver off main thread, "
"to ensure it runs after previous shutdown."));
RefPtr<AsyncCubebTask> initEvent =
new AsyncCubebTask(AsAudioCallbackDriver(), AsyncCubebOperation::INIT);
initEvent->Dispatch();
}
bool AudioCallbackDriver::StartStream() {
AUTO_PROFILER_LABEL("AudioCallbackDriver::StartStream", MEDIA_CUBEB);
MOZ_ASSERT(!IsStarted() && OnCubebOperationThread());
// Set mStarted before cubeb_stream_start, since starting the cubeb stream can
// result in a callback (that may read mStarted) before mStarted would
// otherwise be set to true.
mStarted = true;
if (cubeb_stream_start(mAudioStream) != CUBEB_OK) {
NS_WARNING("Could not start cubeb stream for MTG.");
mStarted = false;
return false;
}
return true;
}
void AudioCallbackDriver::Stop() {
AUTO_PROFILER_LABEL("AudioCallbackDriver::Stop", MEDIA_CUBEB);
MOZ_ASSERT(OnCubebOperationThread());
if (cubeb_stream_stop(mAudioStream) != CUBEB_OK) {
NS_WARNING("Could not stop cubeb stream for MTG.");
}
mStarted = false;
}
void AudioCallbackDriver::Shutdown() {
MOZ_ASSERT(NS_IsMainThread());
RefPtr<FallbackWrapper> fallback;
{
auto fallbackLock = mFallback.Lock();
fallback = fallbackLock.ref();
fallbackLock.ref() = nullptr;
}
if (fallback) {
LOG(LogLevel::Debug,
("%p: Releasing fallback driver %p.", Graph(), fallback.get()));
fallback->Shutdown();
}
LOG(LogLevel::Debug,
("%p: Releasing audio driver off main thread (GraphDriver::Shutdown).",
Graph()));
RefPtr<AsyncCubebTask> releaseEvent =
new AsyncCubebTask(this, AsyncCubebOperation::SHUTDOWN);
releaseEvent->Dispatch(NS_DISPATCH_SYNC);
}
#if defined(XP_WIN)
void AudioCallbackDriver::ResetDefaultDevice() {
AUTO_PROFILER_LABEL("AudioCallbackDriver::ResetDefaultDevice", MEDIA_CUBEB);
if (cubeb_stream_reset_default_device(mAudioStream) != CUBEB_OK) {
NS_WARNING("Could not reset cubeb stream to default output device.");
}
}
#endif
/* static */
long AudioCallbackDriver::DataCallback_s(cubeb_stream* aStream, void* aUser,
const void* aInputBuffer,
void* aOutputBuffer, long aFrames) {
AudioCallbackDriver* driver = reinterpret_cast<AudioCallbackDriver*>(aUser);
return driver->DataCallback(static_cast<const AudioDataValue*>(aInputBuffer),
static_cast<AudioDataValue*>(aOutputBuffer),
aFrames);
}
/* static */
void AudioCallbackDriver::StateCallback_s(cubeb_stream* aStream, void* aUser,
cubeb_state aState) {
AudioCallbackDriver* driver = reinterpret_cast<AudioCallbackDriver*>(aUser);
driver->StateCallback(aState);
}
/* static */
void AudioCallbackDriver::DeviceChangedCallback_s(void* aUser) {
AudioCallbackDriver* driver = reinterpret_cast<AudioCallbackDriver*>(aUser);
driver->DeviceChangedCallback();
}
AudioCallbackDriver::AutoInCallback::AutoInCallback(
AudioCallbackDriver* aDriver)
: mDriver(aDriver) {
MOZ_ASSERT(mDriver->mAudioThreadIdInCb == std::thread::id());
mDriver->mAudioThreadIdInCb = std::this_thread::get_id();
}
AudioCallbackDriver::AutoInCallback::~AutoInCallback() {
MOZ_ASSERT(mDriver->mAudioThreadIdInCb == std::this_thread::get_id());
mDriver->mAudioThreadIdInCb = std::thread::id();
}
bool AudioCallbackDriver::CheckThreadIdChanged() {
#ifdef MOZ_GECKO_PROFILER
auto id = profiler_current_thread_id();
if (id != mAudioThreadId) {
mAudioThreadId = id;
return true;
}
#endif
return false;
}
long AudioCallbackDriver::DataCallback(const AudioDataValue* aInputBuffer,
AudioDataValue* aOutputBuffer,
long aFrames) {
if (!mSandboxed && CheckThreadIdChanged()) {
CubebUtils::GetAudioThreadRegistry()->Register(mAudioThreadId);
}
FallbackDriverState fallbackState = mFallbackDriverState;
if (MOZ_UNLIKELY(fallbackState == FallbackDriverState::Running)) {
// Wait for the fallback driver to stop. Wake it up so it can stop if it's
// sleeping.
EnsureNextIteration();
PodZero(aOutputBuffer, aFrames * mOutputChannelCount);
return aFrames;
}
if (MOZ_UNLIKELY(fallbackState == FallbackDriverState::Stopped)) {
// We're supposed to stop.
PodZero(aOutputBuffer, aFrames * mOutputChannelCount);
if (!mSandboxed) {
CubebUtils::GetAudioThreadRegistry()->Unregister(mAudioThreadId);
}
return aFrames - 1;
}
MOZ_ASSERT(ThreadRunning());
TRACE_AUDIO_CALLBACK_BUDGET(aFrames, mSampleRate);
TRACE();
#ifdef DEBUG
AutoInCallback aic(this);
#endif
if (!mRanFirstIteration) {
Graph()->NotifyStarted();
mRanFirstIteration = true;
}
uint32_t durationMS = aFrames * 1000 / mSampleRate;
// For now, simply average the duration with the previous
// duration so there is some damping against sudden changes.
if (!mIterationDurationMS) {
mIterationDurationMS = durationMS;
} else {
mIterationDurationMS = (mIterationDurationMS * 3) + durationMS;
mIterationDurationMS /= 4;
}
mBuffer.SetBuffer(aOutputBuffer, aFrames);
// fill part or all with leftover data from last iteration (since we
// align to Audio blocks)
mScratchBuffer.Empty(mBuffer);
// State computed time is decided by the audio callback's buffer length. We
// compute the iteration start and end from there, trying to keep the amount
// of buffering in the graph constant.
GraphTime nextStateComputedTime =
MediaTrackGraphImpl::RoundUpToEndOfAudioBlock(mStateComputedTime +
mBuffer.Available());
mIterationStart = mIterationEnd;
// inGraph is the number of audio frames there is between the state time and
// the current time, i.e. the maximum theoretical length of the interval we
// could use as [mIterationStart; mIterationEnd].
GraphTime inGraph = mStateComputedTime - mIterationStart;
// We want the interval [mIterationStart; mIterationEnd] to be before the
// interval [mStateComputedTime; nextStateComputedTime]. We also want
// the distance between these intervals to be roughly equivalent each time, to
// ensure there is no clock drift between current time and state time. Since
// we can't act on the state time because we have to fill the audio buffer, we
// reclock the current time against the state time, here.
mIterationEnd = mIterationStart + 0.8 * inGraph;
LOG(LogLevel::Verbose,
("%p: interval[%ld; %ld] state[%ld; %ld] (frames: %ld) (durationMS: %u) "
"(duration ticks: %ld)",
Graph(), (long)mIterationStart, (long)mIterationEnd,
(long)mStateComputedTime, (long)nextStateComputedTime, (long)aFrames,
(uint32_t)durationMS,
(long)(nextStateComputedTime - mStateComputedTime)));
if (mStateComputedTime < mIterationEnd) {
LOG(LogLevel::Error, ("%p: Media graph global underrun detected", Graph()));
MOZ_ASSERT_UNREACHABLE("We should not underrun in full duplex");
mIterationEnd = mStateComputedTime;
}
// Process mic data if any/needed
if (aInputBuffer && mInputChannelCount > 0) {
Graph()->NotifyInputData(aInputBuffer, static_cast<size_t>(aFrames),
mSampleRate, mInputChannelCount);
}
bool iterate = mBuffer.Available();
IterationResult result =
iterate
? Graph()->OneIteration(nextStateComputedTime, mIterationEnd, &mMixer)
: IterationResult::CreateStillProcessing();
if (iterate) {
// We totally filled the buffer (and mScratchBuffer isn't empty).
// We don't need to run an iteration and if we do so we may overflow.
mStateComputedTime = nextStateComputedTime;
} else {
LOG(LogLevel::Verbose,
("%p: DataCallback buffer filled entirely from scratch "
"buffer, skipping iteration.",
Graph()));
result = IterationResult::CreateStillProcessing();
}
mBuffer.BufferFilled();
#ifdef MOZ_SAMPLE_TYPE_FLOAT32
// Prevent returning NaN to the OS mixer, and propagating NaN into the reverse
// stream of the AEC.
NaNToZeroInPlace(aOutputBuffer, aFrames * mOutputChannelCount);
#endif
// Callback any observers for the AEC speaker data. Note that one
// (maybe) of these will be full-duplex, the others will get their input
// data off separate cubeb callbacks. Take care with how stuff is
// removed/added to this list and TSAN issues, but input and output will
// use separate callback methods.
Graph()->NotifyOutputData(aOutputBuffer, static_cast<size_t>(aFrames),
mSampleRate, mOutputChannelCount);
#ifdef XP_MACOSX
// This only happens when the output is on a macbookpro's external speaker,
// that are stereo, but let's just be safe.
if (mNeedsPanning && mOutputChannelCount == 2) {
// hard pan to the right
for (uint32_t i = 0; i < aFrames * 2; i += 2) {
aOutputBuffer[i + 1] += aOutputBuffer[i];
aOutputBuffer[i] = 0.0;
}
}
#endif
// No-op if MOZ_DUMP_AUDIO is not defined as an environment variable
if (aInputBuffer) {
mInputStreamFile.Write(static_cast<const AudioDataValue*>(aInputBuffer),
aFrames * mInputChannelCount);
}
mOutputStreamFile.Write(static_cast<const AudioDataValue*>(aOutputBuffer),
aFrames * mOutputChannelCount);
if (result.IsStop()) {
// Signal that we have stopped.
result.Stopped();
// Update the flag before handing over the graph and going to drain.
mAudioStreamState = AudioStreamState::Stopping;
if (!mSandboxed) {
CubebUtils::GetAudioThreadRegistry()->Unregister(mAudioThreadId);
}
return aFrames - 1;
}
if (GraphDriver* nextDriver = result.NextDriver()) {
LOG(LogLevel::Debug,
("%p: Switching to %s driver.", Graph(),
nextDriver->AsAudioCallbackDriver() ? "audio" : "system"));
result.Switched();
mAudioStreamState = AudioStreamState::Stopping;
nextDriver->SetState(mIterationStart, mIterationEnd, mStateComputedTime);
nextDriver->Start();
if (!mSandboxed) {
CubebUtils::GetAudioThreadRegistry()->Unregister(mAudioThreadId);
}
// Returning less than aFrames starts the draining and eventually stops the
// audio thread. This function will never get called again.
return aFrames - 1;
}
MOZ_ASSERT(result.IsStillProcessing());
return aFrames;
}
static const char* StateToString(cubeb_state aState) {
switch (aState) {
case CUBEB_STATE_STARTED:
return "STARTED";
case CUBEB_STATE_STOPPED:
return "STOPPED";
case CUBEB_STATE_DRAINED:
return "DRAINED";
case CUBEB_STATE_ERROR:
return "ERROR";
default:
MOZ_CRASH("Unexpected state!");
}
}
void AudioCallbackDriver::StateCallback(cubeb_state aState) {
MOZ_ASSERT(!InIteration());
LOG(LogLevel::Debug,
("AudioCallbackDriver(%p) State: %s", this, StateToString(aState)));
// Clear the flag for the not running and error states (stopped, drained)
AudioStreamState streamState = mAudioStreamState.exchange(
aState == CUBEB_STATE_STARTED
? AudioStreamState::Running
: aState == CUBEB_STATE_ERROR ? AudioStreamState::Errored
: AudioStreamState::None);
if (aState == CUBEB_STATE_ERROR) {
// About to hand over control of the graph. Do not start a new driver if
// StateCallback() receives an error for this stream while the main thread
// or another driver has control of the graph.
if (streamState == AudioStreamState::Running) {
MOZ_ASSERT(!ThreadRunning());
FallbackToSystemClockDriver();
}
} else if (aState == CUBEB_STATE_STOPPED) {
MOZ_ASSERT(!ThreadRunning());
}
}
void AudioCallbackDriver::MixerCallback(AudioDataValue* aMixedBuffer,
AudioSampleFormat aFormat,
uint32_t aChannels, uint32_t aFrames,
uint32_t aSampleRate) {
MOZ_ASSERT(InIteration());
uint32_t toWrite = mBuffer.Available();
if (!mBuffer.Available()) {
NS_WARNING("DataCallback buffer full, expect frame drops.");
}
MOZ_ASSERT(mBuffer.Available() <= aFrames);
mBuffer.WriteFrames(aMixedBuffer, mBuffer.Available());
MOZ_ASSERT(mBuffer.Available() == 0,
"Missing frames to fill audio callback's buffer.");
DebugOnly<uint32_t> written = mScratchBuffer.Fill(
aMixedBuffer + toWrite * aChannels, aFrames - toWrite);
NS_WARNING_ASSERTION(written == aFrames - toWrite, "Dropping frames.");
};
void AudioCallbackDriver::PanOutputIfNeeded(bool aMicrophoneActive) {
#ifdef XP_MACOSX
AUTO_PROFILER_LABEL("AudioCallbackDriver::PanOutputIfNeeded", MEDIA_CUBEB);
cubeb_device* out = nullptr;
int rv;
char name[128];
size_t length = sizeof(name);
rv = sysctlbyname("hw.model", name, &length, NULL, 0);
if (rv) {
return;
}
int major, minor;
for (uint32_t i = 0; i < length; i++) {
// skip the model name
if (isalpha(name[i])) {
continue;
}
sscanf(name + i, "%d,%d", &major, &minor);
break;
}
enum MacbookModel { MacBook, MacBookPro, MacBookAir, NotAMacbook };
MacbookModel model;
if (!strncmp(name, "MacBookPro", length)) {
model = MacBookPro;
} else if (strncmp(name, "MacBookAir", length)) {
model = MacBookAir;
} else if (strncmp(name, "MacBook", length)) {
model = MacBook;
} else {
model = NotAMacbook;
}
// For macbook pro before 2016 model (change of chassis), hard pan the audio
// to the right if the speakers are in use to avoid feedback.
if (model == MacBookPro && major <= 12) {
if (cubeb_stream_get_current_device(mAudioStream, &out) == CUBEB_OK) {
MOZ_ASSERT(out);
// Check if we are currently outputing sound on external speakers.
if (out->output_name && !strcmp(out->output_name, "ispk")) {
// Pan everything to the right speaker.
LOG(LogLevel::Debug, ("Using the built-in speakers, with%s audio input",
aMicrophoneActive ? "" : "out"));
mNeedsPanning = aMicrophoneActive;
} else {
LOG(LogLevel::Debug, ("Using an external output device"));
mNeedsPanning = false;
}
cubeb_stream_device_destroy(mAudioStream, out);
}
}
#endif
}
void AudioCallbackDriver::DeviceChangedCallback() {
MOZ_ASSERT(!InIteration());
// Tell the audio engine the device has changed, it might want to reset some
// state.
Graph()->DeviceChanged();
#ifdef XP_MACOSX
RefPtr<AudioCallbackDriver> self(this);
bool hasInput = mInputChannelCount;
NS_DispatchBackgroundTask(NS_NewRunnableFunction(
"PanOutputIfNeeded", [self{std::move(self)}, hasInput]() {
self->PanOutputIfNeeded(hasInput);
}));
#endif
}
uint32_t AudioCallbackDriver::IterationDuration() {
MOZ_ASSERT(InIteration());
// The real fix would be to have an API in cubeb to give us the number. Short
// of that, we approximate it here. bug 1019507
return mIterationDurationMS;
}
void AudioCallbackDriver::EnsureNextIteration() {
if (mFallbackDriverState == FallbackDriverState::Running) {
auto fallback = mFallback.Lock();
if (fallback.ref()) {
fallback.ref()->EnsureNextIteration();
}
}
}
bool AudioCallbackDriver::IsStarted() { return mStarted; }
TimeDuration AudioCallbackDriver::AudioOutputLatency() {
AUTO_PROFILER_LABEL("AudioCallbackDriver::AudioOutputLatency", MEDIA_CUBEB);
uint32_t latencyFrames;
int rv = cubeb_stream_get_latency(mAudioStream, &latencyFrames);
if (rv || mSampleRate == 0) {
return TimeDuration::FromSeconds(0.0);
}
return TimeDuration::FromSeconds(static_cast<double>(latencyFrames) /
mSampleRate);
}
TimeDuration AudioCallbackDriver::AudioInputLatency() {
uint32_t latencyFrames;
int rv = cubeb_stream_get_input_latency(mAudioStream, &latencyFrames);
if (rv || mSampleRate == 0) {
return TimeDuration::FromSeconds(0.0);
}
return TimeDuration::FromSeconds(static_cast<double>(latencyFrames) /
mSampleRate);
}
void AudioCallbackDriver::FallbackToSystemClockDriver() {
MOZ_ASSERT(!ThreadRunning());
MOZ_ASSERT(mAudioStreamState == AudioStreamState::None ||
mAudioStreamState == AudioStreamState::Errored ||
mAudioStreamState == AudioStreamState::Pending);
MOZ_ASSERT(mFallbackDriverState == FallbackDriverState::None);
LOG(LogLevel::Debug,
("%p: AudioCallbackDriver %p Falling back to SystemClockDriver.", Graph(),
this));
mFallbackDriverState = FallbackDriverState::Running;
mNextReInitBackoffStep =
TimeDuration::FromMilliseconds(AUDIO_INITIAL_FALLBACK_BACKOFF_STEP_MS);
mNextReInitAttempt = TimeStamp::Now() + mNextReInitBackoffStep;
auto fallback =
MakeRefPtr<FallbackWrapper>(Graph(), this, mSampleRate, mIterationStart,
mIterationEnd, mStateComputedTime);
{
auto driver = mFallback.Lock();
driver.ref() = fallback;
}
fallback->Start();
}
void AudioCallbackDriver::FallbackDriverStopped(GraphTime aIterationStart,
GraphTime aIterationEnd,
GraphTime aStateComputedTime,
FallbackDriverState aState) {
mIterationStart = aIterationStart;
mIterationEnd = aIterationEnd;
mStateComputedTime = aStateComputedTime;
mNextReInitAttempt = TimeStamp();
mNextReInitBackoffStep = TimeDuration();
{
auto fallback = mFallback.Lock();
MOZ_ASSERT(fallback.ref()->OnThread());
fallback.ref() = nullptr;
}
MOZ_ASSERT(aState == FallbackDriverState::None ||
aState == FallbackDriverState::Stopped);
MOZ_ASSERT_IF(aState == FallbackDriverState::None,
mAudioStreamState == AudioStreamState::Running);
mFallbackDriverState = aState;
}
void AudioCallbackDriver::MaybeStartAudioStream() {
AudioStreamState streamState = mAudioStreamState;
MOZ_ASSERT(
streamState != AudioStreamState::Errored,
"An errored stream must not attempted to be re-started, an error stream"
" has already beed started once");
if (streamState != AudioStreamState::None) {
LOG(LogLevel::Verbose,
("%p: AudioCallbackDriver %p Cannot re-init.", Graph(), this));
return;
}
TimeStamp now = TimeStamp::Now();
if (now < mNextReInitAttempt) {
LOG(LogLevel::Verbose,
("%p: AudioCallbackDriver %p Not time to re-init yet. %.3fs left.",
Graph(), this, (mNextReInitAttempt - now).ToSeconds()));
return;
}
LOG(LogLevel::Debug, ("%p: AudioCallbackDriver %p Attempting to re-init "
"audio stream from fallback driver.",
Graph(), this));
mNextReInitBackoffStep = std::min(
mNextReInitBackoffStep * 2,
TimeDuration::FromMilliseconds(AUDIO_MAX_FALLBACK_BACKOFF_STEP_MS));
mNextReInitAttempt = now + mNextReInitBackoffStep;
Start();
}
} // namespace mozilla
// avoid redefined macro in unified build
#undef LOG