media/audio/pulse/audio_manager_pulse.cc - cobalt - Git at Google

 // Copyright 2013 The Chromium Authors
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.

 #include "media/audio/pulse/audio_manager_pulse.h"

 #include <algorithm>
 #include <utility>

 #include "base/command_line.h"
 #include "base/environment.h"
 #include "base/logging.h"
 #include "base/nix/xdg_util.h"
 #include "build/chromeos_buildflags.h"
 #include "media/audio/audio_device_description.h"
 #include "media/audio/pulse/pulse_input.h"
 #include "media/audio/pulse/pulse_output.h"
 #include "media/audio/pulse/pulse_util.h"
 #include "media/base/audio_parameters.h"
 #include "media/base/channel_layout.h"

 namespace media {

 using pulse::AutoPulseLock;
 using pulse::WaitForOperationCompletion;

 // Maximum number of output streams that can be open simultaneously.
 constexpr int kMaxOutputStreams = 50;

 constexpr int kMinimumOutputBufferSize = 512;
 constexpr int kMaximumOutputBufferSize = 8192;
 constexpr int kDefaultInputBufferSize = 1024;
 constexpr int kDefaultSampleRate = 48000;
 constexpr int kDefaultChannelCount = 2;

 AudioManagerPulse::AudioManagerPulse(std::unique_ptr<AudioThread> audio_thread,
                                      AudioLogFactory* audio_log_factory,
                                      pa_threaded_mainloop* pa_mainloop,
                                      pa_context* pa_context)
     : AudioManagerBase(std::move(audio_thread), audio_log_factory),
       input_mainloop_(pa_mainloop),
       input_context_(pa_context),
       devices_(nullptr),
       native_input_sample_rate_(kDefaultSampleRate),
       native_channel_count_(kDefaultChannelCount),
       default_source_is_monitor_(false) {
   DCHECK(input_mainloop_);
   DCHECK(input_context_);
   SetMaxOutputStreamsAllowed(kMaxOutputStreams);
 }

 AudioManagerPulse::~AudioManagerPulse() = default;

 void AudioManagerPulse::ShutdownOnAudioThread() {
   AudioManagerBase::ShutdownOnAudioThread();
   // The Pulse objects are the last things to be destroyed since
   // AudioManagerBase::ShutdownOnAudioThread() needs them.
   pulse::DestroyPulse(input_mainloop_.ExtractAsDangling(),
                       input_context_.ExtractAsDangling());
 }

 bool AudioManagerPulse::HasAudioOutputDevices() {
   AudioDeviceNames devices;
   GetAudioOutputDeviceNames(&devices);
   return !devices.empty();
 }

 bool AudioManagerPulse::HasAudioInputDevices() {
   AudioDeviceNames devices;
   GetAudioInputDeviceNames(&devices);
   return !devices.empty();
 }

 void AudioManagerPulse::GetAudioDeviceNames(
     bool input, media::AudioDeviceNames* device_names) {
   DCHECK(device_names->empty());
   DCHECK(input_mainloop_);
   DCHECK(input_context_);
   AutoPulseLock auto_lock(input_mainloop_);
   devices_ = device_names;
   pa_operation* operation = NULL;
   if (input) {
     operation = pa_context_get_source_info_list(
       input_context_, InputDevicesInfoCallback, this);
   } else {
     operation = pa_context_get_sink_info_list(
         input_context_, OutputDevicesInfoCallback, this);
   }
   WaitForOperationCompletion(input_mainloop_, operation, input_context_);

   // Prepend the default device if the list is not empty.
   if (!device_names->empty())
     device_names->push_front(AudioDeviceName::CreateDefault());
 }

 void AudioManagerPulse::GetAudioInputDeviceNames(
     AudioDeviceNames* device_names) {
   GetAudioDeviceNames(true, device_names);
 }

 void AudioManagerPulse::GetAudioOutputDeviceNames(
     AudioDeviceNames* device_names) {
   GetAudioDeviceNames(false, device_names);
 }

 AudioParameters AudioManagerPulse::GetInputStreamParameters(
     const std::string& device_id) {
   UpdateNativeAudioHardwareInfo();

   {
     AutoPulseLock auto_lock(input_mainloop_);
     auto* operation = pa_context_get_source_info_by_name(
         input_context_, default_source_name_.c_str(), DefaultSourceInfoCallback,
         this);
     WaitForOperationCompletion(input_mainloop_, operation, input_context_);
   }

   // We don't want to accidentally open a monitor device, so return invalid
   // parameters for those. Note: The value of |default_source_is_monitor_|
   // depends on the the call to pa_context_get_source_info_by_name() above.
   if (device_id == AudioDeviceDescription::kDefaultDeviceId &&
       default_source_is_monitor_) {
     return AudioParameters();
   }

   const int user_buffer_size = GetUserBufferSize();
   const int buffer_size =
       user_buffer_size ? user_buffer_size : kDefaultInputBufferSize;
   return AudioParameters(AudioParameters::AUDIO_PCM_LOW_LATENCY,
                          ChannelLayoutConfig::Stereo(),
                          native_input_sample_rate_ ? native_input_sample_rate_
                                                    : kDefaultSampleRate,
                          buffer_size);
 }

 const char* AudioManagerPulse::GetName() {
   return "PulseAudio";
 }

 AudioOutputStream* AudioManagerPulse::MakeLinearOutputStream(
     const AudioParameters& params,
     const LogCallback& log_callback) {
   DCHECK_EQ(AudioParameters::AUDIO_PCM_LINEAR, params.format());
   return MakeOutputStream(params, AudioDeviceDescription::kDefaultDeviceId,
                           log_callback);
 }

 AudioOutputStream* AudioManagerPulse::MakeLowLatencyOutputStream(
     const AudioParameters& params,
     const std::string& device_id,
     const LogCallback& log_callback) {
   DCHECK_EQ(AudioParameters::AUDIO_PCM_LOW_LATENCY, params.format());
   return MakeOutputStream(
       params,
       device_id.empty() ? AudioDeviceDescription::kDefaultDeviceId : device_id,
       log_callback);
 }

 AudioInputStream* AudioManagerPulse::MakeLinearInputStream(
     const AudioParameters& params,
     const std::string& device_id,
     const LogCallback& log_callback) {
   DCHECK_EQ(AudioParameters::AUDIO_PCM_LINEAR, params.format());
   return MakeInputStream(params, device_id, log_callback);
 }

 AudioInputStream* AudioManagerPulse::MakeLowLatencyInputStream(
     const AudioParameters& params,
     const std::string& device_id,
     const LogCallback& log_callback) {
   DCHECK_EQ(AudioParameters::AUDIO_PCM_LOW_LATENCY, params.format());
   return MakeInputStream(params, device_id, log_callback);
 }

 std::string AudioManagerPulse::GetDefaultInputDeviceID() {
   // Do not use the real default input device since it is a fallback
   // device rather than a default device. Using the default input device
   // reported by Pulse Audio prevents, for example, input redirection
   // using the PULSE_SOURCE environment variable.
   return AudioManagerBase::GetDefaultInputDeviceID();
 }

 std::string AudioManagerPulse::GetDefaultOutputDeviceID() {
   // Do not use the real default output device since it is a fallback
   // device rather than a default device. Using the default output device
   // reported by Pulse Audio prevents, for example, output redirection
   // using the PULSE_SINK environment variable.
   return AudioManagerBase::GetDefaultOutputDeviceID();
 }

 std::string AudioManagerPulse::GetAssociatedOutputDeviceID(
     const std::string& input_device_id) {
 #if BUILDFLAG(IS_CHROMEOS_ASH)
   return AudioManagerBase::GetAssociatedOutputDeviceID(input_device_id);
 #else
   DCHECK(AudioManager::Get()->GetTaskRunner()->BelongsToCurrentThread());
   DCHECK(input_mainloop_);
   DCHECK(input_context_);

   if (input_device_id == AudioDeviceDescription::kDefaultDeviceId)
     return std::string();

   std::string input_bus =
       pulse::GetBusOfInput(input_mainloop_, input_context_, input_device_id);
   return input_bus.empty() ? std::string()
                            : pulse::GetOutputCorrespondingTo(
                                  input_mainloop_, input_context_, input_bus);
 #endif
 }

 AudioParameters AudioManagerPulse::GetPreferredOutputStreamParameters(
     const std::string& output_device_id,
     const AudioParameters& input_params) {
   // TODO(tommi): Support |output_device_id|.
   VLOG_IF(0, !output_device_id.empty()) << "Not implemented!";

   int buffer_size = kMinimumOutputBufferSize;

   // Query native parameters where applicable; Pulse does not require these to
   // be respected though, so prefer the input parameters for channel count.
   UpdateNativeAudioHardwareInfo();
   int sample_rate = native_input_sample_rate_ ? native_input_sample_rate_
                                               : kDefaultSampleRate;
   ChannelLayoutConfig channel_layout_config = ChannelLayoutConfig::Guess(
       native_channel_count_ ? native_channel_count_ : 2);

   if (input_params.IsValid()) {
     // Use the system's output channel count for the DISCRETE layout. This is to
     // avoid a crash due to the lack of support on the multi-channel beyond 8 in
     // the PulseAudio layer.
     if (input_params.channel_layout() != CHANNEL_LAYOUT_DISCRETE)
       channel_layout_config = input_params.channel_layout_config();

     buffer_size =
         std::min(kMaximumOutputBufferSize,
                  std::max(buffer_size, input_params.frames_per_buffer()));
   }

   int user_buffer_size = GetUserBufferSize();
   if (user_buffer_size)
     buffer_size = user_buffer_size;

   return AudioParameters(AudioParameters::AUDIO_PCM_LOW_LATENCY,
                          channel_layout_config, sample_rate, buffer_size);
 }

 AudioOutputStream* AudioManagerPulse::MakeOutputStream(
     const AudioParameters& params,
     const std::string& device_id,
     LogCallback log_callback) {
   DCHECK(!device_id.empty());
   return new PulseAudioOutputStream(params, device_id, this,
                                     std::move(log_callback));
 }

 AudioInputStream* AudioManagerPulse::MakeInputStream(
     const AudioParameters& params,
     const std::string& device_id,
     LogCallback log_callback) {
   return new PulseAudioInputStream(this, device_id, params, input_mainloop_,
                                    input_context_, std::move(log_callback));
 }

 void AudioManagerPulse::UpdateNativeAudioHardwareInfo() {
   DCHECK(input_mainloop_);
   DCHECK(input_context_);
   AutoPulseLock auto_lock(input_mainloop_);
   pa_operation* operation = pa_context_get_server_info(
       input_context_, AudioHardwareInfoCallback, this);
   WaitForOperationCompletion(input_mainloop_, operation, input_context_);

   // Be careful about adding OS calls to this method.
   // GetPreferredOutputStreamParameters() calls this method on a critical path.
   // If the OS calls hang they will hang all device authorizations.
 }

 void AudioManagerPulse::InputDevicesInfoCallback(pa_context* context,
                                                  const pa_source_info* info,
                                                  int eol,
                                                  void* user_data) {
   AudioManagerPulse* manager = reinterpret_cast<AudioManagerPulse*>(user_data);

   if (eol) {
     // Signal the pulse object that it is done.
     pa_threaded_mainloop_signal(manager->input_mainloop_, 0);
     return;
   }

   // Exclude output monitor (i.e. loopback) devices.
   if (info->monitor_of_sink != PA_INVALID_INDEX)
     return;

   // If the device has ports, but none of them are available, skip it.
   if (info->n_ports > 0) {
     uint32_t port = 0;
     for (; port != info->n_ports; ++port) {
       if (info->ports[port]->available != PA_PORT_AVAILABLE_NO)
         break;
     }
     if (port == info->n_ports)
       return;
   }

   manager->devices_->push_back(AudioDeviceName(info->description, info->name));
 }

 void AudioManagerPulse::OutputDevicesInfoCallback(pa_context* context,
                                                   const pa_sink_info* info,
                                                   int eol,
                                                   void* user_data) {
   AudioManagerPulse* manager = reinterpret_cast<AudioManagerPulse*>(user_data);

   if (eol) {
     // Signal the pulse object that it is done.
     pa_threaded_mainloop_signal(manager->input_mainloop_, 0);
     return;
   }

   manager->devices_->push_back(AudioDeviceName(info->description, info->name));
 }

 void AudioManagerPulse::AudioHardwareInfoCallback(pa_context* context,
                                                   const pa_server_info* info,
                                                   void* user_data) {
   AudioManagerPulse* manager = reinterpret_cast<AudioManagerPulse*>(user_data);

   manager->native_input_sample_rate_ = info->sample_spec.rate;
   manager->native_channel_count_ = info->sample_spec.channels;
   if (info->default_source_name)
     manager->default_source_name_ = info->default_source_name;
   pa_threaded_mainloop_signal(manager->input_mainloop_, 0);
 }

 void AudioManagerPulse::DefaultSourceInfoCallback(pa_context* context,
                                                   const pa_source_info* info,
                                                   int eol,
                                                   void* user_data) {
   AudioManagerPulse* manager = reinterpret_cast<AudioManagerPulse*>(user_data);
   if (eol) {
     // Signal the pulse object that it is done.
     pa_threaded_mainloop_signal(manager->input_mainloop_, 0);
     return;
   }

   DCHECK(info);
   manager->default_source_is_monitor_ =
       info->monitor_of_sink != PA_INVALID_INDEX;
 }

 }  // namespace media
	// Copyright 2013 The Chromium Authors
	// Use of this source code is governed by a BSD-style license that can be
	// found in the LICENSE file.

	#include "media/audio/pulse/audio_manager_pulse.h"

	#include <algorithm>
	#include <utility>

	#include "base/command_line.h"
	#include "base/environment.h"
	#include "base/logging.h"
	#include "base/nix/xdg_util.h"
	#include "build/chromeos_buildflags.h"
	#include "media/audio/audio_device_description.h"
	#include "media/audio/pulse/pulse_input.h"
	#include "media/audio/pulse/pulse_output.h"
	#include "media/audio/pulse/pulse_util.h"
	#include "media/base/audio_parameters.h"
	#include "media/base/channel_layout.h"

	namespace media {

	using pulse::AutoPulseLock;
	using pulse::WaitForOperationCompletion;

	// Maximum number of output streams that can be open simultaneously.
	constexpr int kMaxOutputStreams = 50;

	constexpr int kMinimumOutputBufferSize = 512;
	constexpr int kMaximumOutputBufferSize = 8192;
	constexpr int kDefaultInputBufferSize = 1024;
	constexpr int kDefaultSampleRate = 48000;
	constexpr int kDefaultChannelCount = 2;

	AudioManagerPulse::AudioManagerPulse(std::unique_ptr<AudioThread> audio_thread,
	AudioLogFactory* audio_log_factory,
	pa_threaded_mainloop* pa_mainloop,
	pa_context* pa_context)
	: AudioManagerBase(std::move(audio_thread), audio_log_factory),
	input_mainloop_(pa_mainloop),
	input_context_(pa_context),
	devices_(nullptr),
	native_input_sample_rate_(kDefaultSampleRate),
	native_channel_count_(kDefaultChannelCount),
	default_source_is_monitor_(false) {
	DCHECK(input_mainloop_);
	DCHECK(input_context_);
	SetMaxOutputStreamsAllowed(kMaxOutputStreams);
	}

	AudioManagerPulse::~AudioManagerPulse() = default;

	void AudioManagerPulse::ShutdownOnAudioThread() {
	AudioManagerBase::ShutdownOnAudioThread();
	// The Pulse objects are the last things to be destroyed since
	// AudioManagerBase::ShutdownOnAudioThread() needs them.
	pulse::DestroyPulse(input_mainloop_.ExtractAsDangling(),
	input_context_.ExtractAsDangling());
	}

	bool AudioManagerPulse::HasAudioOutputDevices() {
	AudioDeviceNames devices;
	GetAudioOutputDeviceNames(&devices);
	return !devices.empty();
	}

	bool AudioManagerPulse::HasAudioInputDevices() {
	AudioDeviceNames devices;
	GetAudioInputDeviceNames(&devices);
	return !devices.empty();
	}

	void AudioManagerPulse::GetAudioDeviceNames(
	bool input, media::AudioDeviceNames* device_names) {
	DCHECK(device_names->empty());
	DCHECK(input_mainloop_);
	DCHECK(input_context_);
	AutoPulseLock auto_lock(input_mainloop_);
	devices_ = device_names;
	pa_operation* operation = NULL;
	if (input) {
	operation = pa_context_get_source_info_list(
	input_context_, InputDevicesInfoCallback, this);
	} else {
	operation = pa_context_get_sink_info_list(
	input_context_, OutputDevicesInfoCallback, this);
	}
	WaitForOperationCompletion(input_mainloop_, operation, input_context_);

	// Prepend the default device if the list is not empty.
	if (!device_names->empty())
	device_names->push_front(AudioDeviceName::CreateDefault());
	}

	void AudioManagerPulse::GetAudioInputDeviceNames(
	AudioDeviceNames* device_names) {
	GetAudioDeviceNames(true, device_names);
	}

	void AudioManagerPulse::GetAudioOutputDeviceNames(
	AudioDeviceNames* device_names) {
	GetAudioDeviceNames(false, device_names);
	}

	AudioParameters AudioManagerPulse::GetInputStreamParameters(
	const std::string& device_id) {
	UpdateNativeAudioHardwareInfo();

	{
	AutoPulseLock auto_lock(input_mainloop_);
	auto* operation = pa_context_get_source_info_by_name(
	input_context_, default_source_name_.c_str(), DefaultSourceInfoCallback,
	this);
	WaitForOperationCompletion(input_mainloop_, operation, input_context_);
	}

	// We don't want to accidentally open a monitor device, so return invalid
	// parameters for those. Note: The value of \|default_source_is_monitor_\|
	// depends on the the call to pa_context_get_source_info_by_name() above.
	if (device_id == AudioDeviceDescription::kDefaultDeviceId &&
	default_source_is_monitor_) {
	return AudioParameters();
	}

	const int user_buffer_size = GetUserBufferSize();
	const int buffer_size =
	user_buffer_size ? user_buffer_size : kDefaultInputBufferSize;
	return AudioParameters(AudioParameters::AUDIO_PCM_LOW_LATENCY,
	ChannelLayoutConfig::Stereo(),
	native_input_sample_rate_ ? native_input_sample_rate_
	: kDefaultSampleRate,
	buffer_size);
	}

	const char* AudioManagerPulse::GetName() {
	return "PulseAudio";
	}

	AudioOutputStream* AudioManagerPulse::MakeLinearOutputStream(
	const AudioParameters& params,
	const LogCallback& log_callback) {
	DCHECK_EQ(AudioParameters::AUDIO_PCM_LINEAR, params.format());
	return MakeOutputStream(params, AudioDeviceDescription::kDefaultDeviceId,
	log_callback);
	}

	AudioOutputStream* AudioManagerPulse::MakeLowLatencyOutputStream(
	const AudioParameters& params,
	const std::string& device_id,
	const LogCallback& log_callback) {
	DCHECK_EQ(AudioParameters::AUDIO_PCM_LOW_LATENCY, params.format());
	return MakeOutputStream(
	params,
	device_id.empty() ? AudioDeviceDescription::kDefaultDeviceId : device_id,
	log_callback);
	}

	AudioInputStream* AudioManagerPulse::MakeLinearInputStream(
	const AudioParameters& params,
	const std::string& device_id,
	const LogCallback& log_callback) {
	DCHECK_EQ(AudioParameters::AUDIO_PCM_LINEAR, params.format());
	return MakeInputStream(params, device_id, log_callback);
	}

	AudioInputStream* AudioManagerPulse::MakeLowLatencyInputStream(
	const AudioParameters& params,
	const std::string& device_id,
	const LogCallback& log_callback) {
	DCHECK_EQ(AudioParameters::AUDIO_PCM_LOW_LATENCY, params.format());
	return MakeInputStream(params, device_id, log_callback);
	}

	std::string AudioManagerPulse::GetDefaultInputDeviceID() {
	// Do not use the real default input device since it is a fallback
	// device rather than a default device. Using the default input device
	// reported by Pulse Audio prevents, for example, input redirection
	// using the PULSE_SOURCE environment variable.
	return AudioManagerBase::GetDefaultInputDeviceID();
	}

	std::string AudioManagerPulse::GetDefaultOutputDeviceID() {
	// Do not use the real default output device since it is a fallback
	// device rather than a default device. Using the default output device
	// reported by Pulse Audio prevents, for example, output redirection
	// using the PULSE_SINK environment variable.
	return AudioManagerBase::GetDefaultOutputDeviceID();
	}

	std::string AudioManagerPulse::GetAssociatedOutputDeviceID(
	const std::string& input_device_id) {
	#if BUILDFLAG(IS_CHROMEOS_ASH)
	return AudioManagerBase::GetAssociatedOutputDeviceID(input_device_id);
	#else
	DCHECK(AudioManager::Get()->GetTaskRunner()->BelongsToCurrentThread());
	DCHECK(input_mainloop_);
	DCHECK(input_context_);

	if (input_device_id == AudioDeviceDescription::kDefaultDeviceId)
	return std::string();

	std::string input_bus =
	pulse::GetBusOfInput(input_mainloop_, input_context_, input_device_id);
	return input_bus.empty() ? std::string()
	: pulse::GetOutputCorrespondingTo(
	input_mainloop_, input_context_, input_bus);
	#endif
	}

	AudioParameters AudioManagerPulse::GetPreferredOutputStreamParameters(
	const std::string& output_device_id,
	const AudioParameters& input_params) {
	// TODO(tommi): Support \|output_device_id\|.
	VLOG_IF(0, !output_device_id.empty()) << "Not implemented!";

	int buffer_size = kMinimumOutputBufferSize;

	// Query native parameters where applicable; Pulse does not require these to
	// be respected though, so prefer the input parameters for channel count.
	UpdateNativeAudioHardwareInfo();
	int sample_rate = native_input_sample_rate_ ? native_input_sample_rate_
	: kDefaultSampleRate;
	ChannelLayoutConfig channel_layout_config = ChannelLayoutConfig::Guess(
	native_channel_count_ ? native_channel_count_ : 2);

	if (input_params.IsValid()) {
	// Use the system's output channel count for the DISCRETE layout. This is to
	// avoid a crash due to the lack of support on the multi-channel beyond 8 in
	// the PulseAudio layer.
	if (input_params.channel_layout() != CHANNEL_LAYOUT_DISCRETE)
	channel_layout_config = input_params.channel_layout_config();

	buffer_size =
	std::min(kMaximumOutputBufferSize,
	std::max(buffer_size, input_params.frames_per_buffer()));
	}

	int user_buffer_size = GetUserBufferSize();
	if (user_buffer_size)
	buffer_size = user_buffer_size;

	return AudioParameters(AudioParameters::AUDIO_PCM_LOW_LATENCY,
	channel_layout_config, sample_rate, buffer_size);
	}

	AudioOutputStream* AudioManagerPulse::MakeOutputStream(
	const AudioParameters& params,
	const std::string& device_id,
	LogCallback log_callback) {
	DCHECK(!device_id.empty());
	return new PulseAudioOutputStream(params, device_id, this,
	std::move(log_callback));
	}

	AudioInputStream* AudioManagerPulse::MakeInputStream(
	const AudioParameters& params,
	const std::string& device_id,
	LogCallback log_callback) {
	return new PulseAudioInputStream(this, device_id, params, input_mainloop_,
	input_context_, std::move(log_callback));
	}

	void AudioManagerPulse::UpdateNativeAudioHardwareInfo() {
	DCHECK(input_mainloop_);
	DCHECK(input_context_);
	AutoPulseLock auto_lock(input_mainloop_);
	pa_operation* operation = pa_context_get_server_info(
	input_context_, AudioHardwareInfoCallback, this);
	WaitForOperationCompletion(input_mainloop_, operation, input_context_);

	// Be careful about adding OS calls to this method.
	// GetPreferredOutputStreamParameters() calls this method on a critical path.
	// If the OS calls hang they will hang all device authorizations.
	}

	void AudioManagerPulse::InputDevicesInfoCallback(pa_context* context,
	const pa_source_info* info,
	int eol,
	void* user_data) {
	AudioManagerPulse* manager = reinterpret_cast<AudioManagerPulse*>(user_data);

	if (eol) {
	// Signal the pulse object that it is done.
	pa_threaded_mainloop_signal(manager->input_mainloop_, 0);
	return;
	}

	// Exclude output monitor (i.e. loopback) devices.
	if (info->monitor_of_sink != PA_INVALID_INDEX)
	return;

	// If the device has ports, but none of them are available, skip it.
	if (info->n_ports > 0) {
	uint32_t port = 0;
	for (; port != info->n_ports; ++port) {
	if (info->ports[port]->available != PA_PORT_AVAILABLE_NO)
	break;
	}
	if (port == info->n_ports)
	return;
	}

	manager->devices_->push_back(AudioDeviceName(info->description, info->name));
	}

	void AudioManagerPulse::OutputDevicesInfoCallback(pa_context* context,
	const pa_sink_info* info,
	int eol,
	void* user_data) {
	AudioManagerPulse* manager = reinterpret_cast<AudioManagerPulse*>(user_data);

	if (eol) {
	// Signal the pulse object that it is done.
	pa_threaded_mainloop_signal(manager->input_mainloop_, 0);
	return;
	}

	manager->devices_->push_back(AudioDeviceName(info->description, info->name));
	}

	void AudioManagerPulse::AudioHardwareInfoCallback(pa_context* context,
	const pa_server_info* info,
	void* user_data) {
	AudioManagerPulse* manager = reinterpret_cast<AudioManagerPulse*>(user_data);

	manager->native_input_sample_rate_ = info->sample_spec.rate;
	manager->native_channel_count_ = info->sample_spec.channels;
	if (info->default_source_name)
	manager->default_source_name_ = info->default_source_name;
	pa_threaded_mainloop_signal(manager->input_mainloop_, 0);
	}

	void AudioManagerPulse::DefaultSourceInfoCallback(pa_context* context,
	const pa_source_info* info,
	int eol,
	void* user_data) {
	AudioManagerPulse* manager = reinterpret_cast<AudioManagerPulse*>(user_data);
	if (eol) {
	// Signal the pulse object that it is done.
	pa_threaded_mainloop_signal(manager->input_mainloop_, 0);
	return;
	}

	DCHECK(info);
	manager->default_source_is_monitor_ =
	info->monitor_of_sink != PA_INVALID_INDEX;
	}

	} // namespace media