Adding pulseaudio input support to chrome

media/audio/pulse/audio_manager_pulse.cc

+// Copyright 2013 The Chromium Authors. All rights reserved.
+// 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 "base/command_line.h"
+#include "base/environment.h"
+#include "base/logging.h"
+#include "base/nix/xdg_util.h"
+#include "base/process_util.h"
+#include "base/stl_util.h"
+#include "media/audio/audio_util.h"
+#include "media/audio/pulse/pulse_input.h"
+#include "media/audio/pulse/pulse_output.h"
+#include "media/audio/pulse/pulse_util.h"
+#include "media/audio/pulse/pulse_wrapper.h"
+
+namespace media {
+
+namespace {
+
+// Maximum number of output streams that can be open simultaneously.
+static const int kMaxOutputStreams = 50;
+
+} //  namespace
+
+// static
+AudioManager* AudioManagerPulse::Create() {
+  scoped_ptr<AudioManagerPulse> ret(new AudioManagerPulse());
+  if (ret->Init())
+    return ret.release();
+
+  DVLOG(1) << "PulseAudio is not available on the OS";
+  return NULL;
+}
+
+AudioManagerPulse::AudioManagerPulse()
+    : input_mainloop_(NULL),
+      input_context_(NULL),
+      devices_(NULL),
+      native_input_sample_rate_(0) {
+  SetMaxOutputStreamsAllowed(kMaxOutputStreams);
+}
+
+AudioManagerPulse::~AudioManagerPulse() {
+  Terminate();
+  Shutdown();
+}
+
+// Implementation of AudioManager.
+bool AudioManagerPulse::HasAudioOutputDevices() {
+  // TODO(xians): implement this function.
+  return true;
+}
+
+bool AudioManagerPulse::HasAudioInputDevices() {
+  // TODO(xians): implement this function.
+  return true;
+}
+
+bool AudioManagerPulse::CanShowAudioInputSettings() {
+  scoped_ptr<base::Environment> env(base::Environment::Create());
+
+  switch (base::nix::GetDesktopEnvironment(env.get())) {
+    case base::nix::DESKTOP_ENVIRONMENT_GNOME:
+    case base::nix::DESKTOP_ENVIRONMENT_KDE3:
+    case base::nix::DESKTOP_ENVIRONMENT_KDE4:
+    case base::nix::DESKTOP_ENVIRONMENT_UNITY:
+      return true;
+    case base::nix::DESKTOP_ENVIRONMENT_OTHER:
+    case base::nix::DESKTOP_ENVIRONMENT_XFCE:
+      return false;
+  }
+  // Unless GetDesktopEnvironment() badly misbehaves, this should never happen.
+  NOTREACHED();
+  return false;
+}
+
+void AudioManagerPulse::ShowAudioInputSettings() {
+  scoped_ptr<base::Environment> env(base::Environment::Create());
+  CommandLine command_line(CommandLine::NO_PROGRAM);
+  switch (base::nix::GetDesktopEnvironment(env.get())) {
+    case base::nix::DESKTOP_ENVIRONMENT_GNOME:
+      command_line.SetProgram(base::FilePath("gnome-volume-control"));
+      break;
+    case base::nix::DESKTOP_ENVIRONMENT_KDE3:
+    case base::nix::DESKTOP_ENVIRONMENT_KDE4:
+      command_line.SetProgram(base::FilePath("kmix"));
+      break;
+    case base::nix::DESKTOP_ENVIRONMENT_UNITY:
+      command_line.SetProgram(base::FilePath("gnome-control-center"));
+      command_line.AppendArg("sound");
+      command_line.AppendArg("input");
+      break;
+    default:
+      LOG(ERROR) << "Failed to show audio input settings: we don't know "
+                 << "what command to use for your desktop environment.";
+      return;
+  }
+  base::LaunchProcess(command_line, base::LaunchOptions(), NULL);
+}
+
+void AudioManagerPulse::GetAudioInputDeviceNames(
+    media::AudioDeviceNames* device_names) {
+  DCHECK(device_names->empty());
+  DCHECK(input_mainloop_);
+  DCHECK(input_context_);
+  devices_ = device_names;
+  AutoPulseLock auto_lock(wrapper_.get(), input_mainloop_);
+  pa_operation* operation = wrapper_->pa_context_get_source_info_list_(
+      input_context_, DevicesInfoCallback, this);
+  WaitForOperationCompletion(wrapper_.get(), input_mainloop_, operation);
+
+  if (!device_names->empty()) {
+    device_names->push_front(
+        AudioDeviceName(AudioManagerBase::kDefaultDeviceName,
+                        AudioManagerBase::kDefaultDeviceId));
+  }
+}
+
+AudioOutputStream* AudioManagerPulse::MakeLinearOutputStream(
+    const AudioParameters& params) {
+  DCHECK_EQ(AudioParameters::AUDIO_PCM_LINEAR, params.format());
+  return MakeOutputStream(params);
+}
+
+AudioOutputStream* AudioManagerPulse::MakeLowLatencyOutputStream(
+    const AudioParameters& params) {
+  DCHECK_EQ(AudioParameters::AUDIO_PCM_LOW_LATENCY, params.format());
+  return MakeOutputStream(params);
+}
+
+AudioInputStream* AudioManagerPulse::MakeLinearInputStream(
+    const AudioParameters& params, const std::string& device_id) {
+  DCHECK_EQ(AudioParameters::AUDIO_PCM_LINEAR, params.format());
+  return MakeInputStream(params, device_id);
+}
+
+AudioInputStream* AudioManagerPulse::MakeLowLatencyInputStream(
+    const AudioParameters& params, const std::string& device_id) {
+  DCHECK_EQ(AudioParameters::AUDIO_PCM_LOW_LATENCY, params.format());
+  return MakeInputStream(params, device_id);
+}
+
+AudioOutputStream* AudioManagerPulse::MakeOutputStream(
+    const AudioParameters& params) {
+  return new PulseAudioOutputStream(wrapper_.get(), params, this);
+}
+
+AudioInputStream* AudioManagerPulse::MakeInputStream(
+    const AudioParameters& params, const std::string& device_id) {
+  return new PulseAudioInputStream(wrapper_.get(), this, device_id, params,
+                                   input_mainloop_, input_context_);
+}
+
+AudioParameters AudioManagerPulse::GetPreferredLowLatencyOutputStreamParameters(
+    const AudioParameters& input_params) {
+  // TODO(xians): figure out the optimized buffer size for the Pulse IO.
+  int buffer_size = GetAudioHardwareBufferSize();
+  if (input_params.frames_per_buffer() < buffer_size)
+    buffer_size = input_params.frames_per_buffer();
+
+  // TODO(dalecurtis): This should include bits per channel and channel layout
+  // eventually.
+  return AudioParameters(
+      AudioParameters::AUDIO_PCM_LOW_LATENCY, input_params.channel_layout(),
+      input_params.sample_rate(), 16, buffer_size);

[DaleCurtis, 2013/02/15 00:28:51]

We can land it this way, but I'm pretty sure we'll need to use the native sample
rate if we want good pulse performance with tiny buffers.

[no longer working on chromium, 2013/02/15 16:07:33]

Yes, we definitely need to use the native sample rate.

+}
+
+int AudioManagerPulse::GetNativeSampleRate() {

[DaleCurtis, 2013/02/15 00:28:51]

We'll want to plumb this into AudioUtil for before we make this the default, or
go ahead and move all audio_util calls onto the AudioManager. (I'm working on
it!)

[no longer working on chromium, 2013/02/15 16:07:33]

Great, FYI, we need to access some member variable for this
AudioManagerPulse::GetNativeSampleRate, like  input_context_, we might need to
create a virtual interface in the AudioManager, instead of using static
functions.

+  DCHECK(input_mainloop_);
+  DCHECK(input_context_);
+  AutoPulseLock auto_lock(wrapper_.get(), input_mainloop_);
+  pa_operation* operation = wrapper_->pa_context_get_server_info_(
+      input_context_, SamplerateInfoCallback, this);
+  WaitForOperationCompletion(wrapper_.get(), input_mainloop_, operation);
+
+  return native_input_sample_rate_;
+}
+
+bool AudioManagerPulse::Init() {
+  DCHECK(!input_mainloop_);
+
+  wrapper_.reset(PulseWrapper::Create());
+  if (!wrapper_) {
+    DLOG(WARNING) << "Failed on loading the Pulse library and symbols";
+    return false;
+  }
+  DLOG(WARNING) << "after loading the Pulse library and symbols";
+  // Create a mainloop API and connect to the default server.
+  // The mainloop is the internal asynchronous API event loop.
+  input_mainloop_ = wrapper_->pa_threaded_mainloop_new_();
+  if (!input_mainloop_)
+    return false;
+  DLOG(WARNING) << "after 2";
+  // Start the threaded mainloop.
+  if (wrapper_->pa_threaded_mainloop_start_(input_mainloop_)) {
+    Terminate();
+    return false;
+  }
+
+  // Lock the event loop object, effectively blocking the event loop thread
+  // from processing events. This is necessary.
+  AutoPulseLock auto_lock(wrapper_.get(), input_mainloop_);
+
+  pa_mainloop_api* pa_mainloop_api =
+      wrapper_->pa_threaded_mainloop_get_api_(input_mainloop_);
+  input_context_ = wrapper_->pa_context_new_(pa_mainloop_api, "Chrome input");
+  DCHECK(input_context_) << "Failed to create PA context";
+  if (!input_context_) {
+    return false;
+  }
+
+  wrapper_->pa_context_set_state_callback_(
+      input_context_, &ContextStateCallback, this);
+  if (wrapper_->pa_context_connect_(input_context_, NULL,
+                                    PA_CONTEXT_NOAUTOSPAWN, NULL)) {
+    DLOG(ERROR) << "Failed to connect to the context";
+    return false;
+  }
+
+  // Wait until |input_context_| is ready.  pa_threaded_mainloop_wait() must be
+  // called after pa_context_get_state() in case the context is already ready,
+  // otherwise pa_threaded_mainloop_wait() will hang indefinitely.
+  while (true) {
+    pa_context_state_t context_state =
+        wrapper_->pa_context_get_state_(input_context_);
+    if (!PA_CONTEXT_IS_GOOD(context_state)) {
+      return false;
+    }
+    if (context_state == PA_CONTEXT_READY)
+      break;
+    wrapper_->pa_threaded_mainloop_wait_(input_mainloop_);
+  }
+
+  return true;
+}
+
+void AudioManagerPulse::Terminate() {
+  if (!input_mainloop_) {
+    DCHECK(!input_context_);
+    return;
+  }
+
+  {
+    AutoPulseLock auto_lock(wrapper_.get(), input_mainloop_);
+    if (input_context_) {
+      // Clear our state callback.
+      wrapper_->pa_context_set_state_callback_(input_context_, NULL, NULL);
+      wrapper_->pa_context_disconnect_(input_context_);
+      wrapper_->pa_context_unref_(input_context_);
+      input_context_ = NULL;
+    }
+  }
+
+  wrapper_->pa_threaded_mainloop_stop_(input_mainloop_);
+  wrapper_->pa_threaded_mainloop_free_(input_mainloop_);
+  input_mainloop_ = NULL;
+}
+
+// static, |pa_context| state changed cb.
+void AudioManagerPulse::ContextStateCallback(pa_context* context,
+                                             void* user_data) {
+  AudioManagerPulse* manager = reinterpret_cast<AudioManagerPulse*>(user_data);
+  manager->wrapper_->pa_threaded_mainloop_signal_(manager->input_mainloop_, 0);
+}
+
+void AudioManagerPulse::DevicesInfoCallback(pa_context* context,
+                                            const pa_source_info* info,
+                                            int error, void *user_data) {
+  AudioManagerPulse* manager = reinterpret_cast<AudioManagerPulse*>(user_data);
+
+  if (error) {
+    // Signal the pulse object that it is done.
+    manager->wrapper_->pa_threaded_mainloop_signal_(
+        manager->input_mainloop_, 0);
+    return;
+  }
+
+  // Exclude the output devices.
+  if (info->monitor_of_sink == PA_INVALID_INDEX) {
+    manager->devices_->push_back(media::AudioDeviceName(info->description,
+                                                      info->name));
+  }
+}
+
+void AudioManagerPulse::SamplerateInfoCallback(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->wrapper_->pa_threaded_mainloop_signal_(manager->input_mainloop_, 0);
+}
+
+}  // namespace media