Adding pulseaudio input support to chrome

media/audio/pulse/pulse_input.cc

+// Copyright (c) 2012 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/pulse_input.h"
+
+#include "base/logging.h"
+#include "base/message_loop.h"
+#include "media/audio/audio_manager_base.h"
+#include "media/audio/pulse/pulse_util.h"
+#include "media/base/seekable_buffer.h"
+
+namespace media {
+
+PulseAudioInputStream::PulseAudioInputStream(AudioManagerBase* audio_manager,
+                                             const std::string& device_name,
+                                             const AudioParameters& params,
+                                             pa_threaded_mainloop* mainloop,
+                                             pa_context* context)
+    : audio_manager_(audio_manager),
+      callback_(NULL),
+      device_name_(device_name),
+      params_(params),
+      channels_(0),
+      volume_(0.0),
+      stream_started_(false),
+      pa_mainloop_(mainloop),
+      pa_context_(context),
+      handle_(NULL) {
+  DCHECK(audio_manager_->GetMessageLoop()->BelongsToCurrentThread());
+  DCHECK(mainloop);
+  DCHECK(context);
+}
+
+PulseAudioInputStream::~PulseAudioInputStream() {
+  // All internal structures should already have been freed in Close(),
+  // which calls AudioManagerPulse::Release which deletes this object.
+  DCHECK(!handle_);
+}
+
+bool PulseAudioInputStream::Open() {
+  DCHECK(audio_manager_->GetMessageLoop()->BelongsToCurrentThread());
+  AutoPulseLock auto_lock(pa_mainloop_);
+
+  // Set sample specifications.
+  pa_sample_spec pa_sample_specifications;
+  pa_sample_specifications.format = BitsToPASampleFormat(
+      params_.bits_per_sample());
+  pa_sample_specifications.rate = params_.sample_rate();
+  pa_sample_specifications.channels = params_.channels();
+
+  // Get channel mapping and open recording stream.
+  pa_channel_map source_channel_map = ChannelLayoutToPAChannelMap(
+      params_.channel_layout());
+  pa_channel_map* map = (source_channel_map.channels != 0)?
+      &source_channel_map : NULL;
+
+  // Create a new recording stream.
+  handle_ = pa_stream_new(pa_context_, "RecordStream",
+                          &pa_sample_specifications, map);
+  if (!handle_) {
+    DLOG(ERROR) << "Open: failed to create PA stream";
+    return false;
+  }
+
+  pa_stream_set_state_callback(handle_, &StreamNotifyCallback, this);
+  pa_stream_set_read_callback(handle_, &ReadCallback, this);
+  pa_stream_readable_size(handle_);
+
+  // Set server-side capture buffer metrics. Detailed documentation on what
+  // values should be chosen can be found at
+  // freedesktop.org/software/pulseaudio/doxygen/structpa__buffer__attr.html.
+  pa_buffer_attr buffer_attributes;
+  const unsigned int buffer_size = params_.GetBytesPerBuffer();
+  buffer_attributes.maxlength =  static_cast<uint32_t>(-1);
+  buffer_attributes.tlength = buffer_size;
+  buffer_attributes.minreq = buffer_size;
+  buffer_attributes.prebuf = static_cast<uint32_t>(-1);
+  buffer_attributes.fragsize = buffer_size;
+  int flags = PA_STREAM_AUTO_TIMING_UPDATE |
+              PA_STREAM_INTERPOLATE_TIMING |
+              PA_STREAM_ADJUST_LATENCY |
+              PA_STREAM_START_CORKED;
+  int err = pa_stream_connect_record(
+      handle_,
+      device_name_ == AudioManagerBase::kDefaultDeviceId ?
+          NULL : device_name_.c_str(),
+      &buffer_attributes,
+      static_cast<pa_stream_flags_t>(flags));
+  if (err) {
+    DLOG(ERROR) << "pa_stream_connect_playback FAILED " << err;
+    return false;
+  }
+
+  // Wait for the stream to be ready.
+  while (true) {
+    pa_stream_state_t stream_state = pa_stream_get_state(handle_);
+    if(!PA_STREAM_IS_GOOD(stream_state)) {
+      DLOG(ERROR) << "Invalid PulseAudio stream state";
+      return false;
+    }
+
+    if (stream_state == PA_STREAM_READY)
+      break;
+    pa_threaded_mainloop_wait(pa_mainloop_);
+  }
+
+  pa_stream_set_read_callback(handle_, &ReadCallback, this);
+  pa_stream_readable_size(handle_);
+
+  buffer_.reset(new media::SeekableBuffer(0, 2 * params_.GetBytesPerBuffer()));
+  audio_data_buffer_.reset(new uint8[params_.GetBytesPerBuffer()]);
+  return true;
+}
+
+void PulseAudioInputStream::Start(AudioInputCallback* callback) {
+  DCHECK(audio_manager_->GetMessageLoop()->BelongsToCurrentThread());
+  DCHECK(callback);
+  DCHECK(handle_);
+  AutoPulseLock auto_lock(pa_mainloop_);
+
+  if (stream_started_)
+    return;
+
+  // Clean up the old buffer.
+  pa_stream_drop(handle_);
+
+  // Start the streaming.
+  stream_started_ = true;
+  callback_ = callback;
+
+  pa_operation* operation = pa_stream_cork(handle_, 0, NULL, NULL);
+  WaitForOperationCompletion(pa_mainloop_, operation);
+}
+
+void PulseAudioInputStream::Stop() {
+  DCHECK(audio_manager_->GetMessageLoop()->BelongsToCurrentThread());
+  AutoPulseLock auto_lock(pa_mainloop_);
+  if (!stream_started_)
+    return;
+
+  // Set the flag to false to stop filling new data to soundcard.
+  stream_started_ = false;
+
+  pa_operation* operation = pa_stream_flush(
+      handle_, &StreamSuccessCallback, pa_mainloop_);
+  WaitForOperationCompletion(pa_mainloop_, operation);
+
+  // Stop the stream.
+  pa_stream_set_read_callback(handle_, NULL, NULL);
+  operation = pa_stream_cork(handle_, 1, &StreamSuccessCallback, pa_mainloop_);
+  WaitForOperationCompletion(pa_mainloop_, operation);
+}
+
+void PulseAudioInputStream::Close() {
+  DCHECK(audio_manager_->GetMessageLoop()->BelongsToCurrentThread());
+  {
+    AutoPulseLock auto_lock(pa_mainloop_);
+    if (handle_) {
+      // Disable all the callbacks before disconnecting.
+      pa_stream_set_state_callback(handle_, NULL, NULL);
+      pa_stream_flush(handle_, NULL, NULL);
+
+      if (pa_stream_get_state(handle_) != PA_STREAM_UNCONNECTED)
+        pa_stream_disconnect(handle_);
+
+      // Release PulseAudio structures.
+      pa_stream_unref(handle_);
+      handle_ = NULL;
+    }
+  }
+
+  if (callback_)
+    callback_->OnClose(this);
+
+  // Signal to the manager that we're closed and can be removed.
+  // This should be the last call in the function as it deletes "this".
+  audio_manager_->ReleaseInputStream(this);
+}
+
+double PulseAudioInputStream::GetMaxVolume() {
+  return static_cast<double>(PA_VOLUME_NORM);
+}
+
+void PulseAudioInputStream::SetVolume(double volume) {
+  AutoPulseLock auto_lock(pa_mainloop_);
+  if (!handle_)
+    return;
+
+  size_t index = pa_stream_get_device_index(handle_);
+  pa_operation* operation = NULL;
+  if (!channels_) {
+    // Get the number of channels for the source only when the |channels_| is 0.
+    // We are assuming the stream source is not changed on the fly here.
+    operation = pa_context_get_source_info_by_index(
+        pa_context_, index, &VolumeCallback, this);
+    WaitForOperationCompletion(pa_mainloop_, operation);
+    if (!channels_) {
+      DLOG(WARNING) << "Failed to get the number of channels for the source";
+      return;
+    }
+  }
+
+  pa_cvolume pa_volume;
+  pa_cvolume_set(&pa_volume, channels_, volume);
+  operation = pa_context_set_source_volume_by_index(
+      pa_context_, index, &pa_volume, NULL, NULL);
+
+  // Don't need to wait for this task to complete.
+  pa_operation_unref(operation);
+}
+
+double PulseAudioInputStream::GetVolume() {
+  AutoPulseLock auto_lock(pa_mainloop_);
+  if (!handle_)
+    return 0.0;
+
+  size_t index = pa_stream_get_device_index(handle_);
+  pa_operation* operation = pa_context_get_source_info_by_index(
+      pa_context_, index, &VolumeCallback, this);
+  WaitForOperationCompletion(pa_mainloop_, operation);
+
+  return volume_;
+}
+
+// static, used by pa_stream_set_read_callback.
+void PulseAudioInputStream::ReadCallback(pa_stream* handle,
+                                         size_t length,
+                                         void* user_data) {
+  PulseAudioInputStream* stream =
+      reinterpret_cast<PulseAudioInputStream*>(user_data);
+
+  stream->ReadData();
+}
+
+// static, used by pa_context_get_source_info_by_index.
+void PulseAudioInputStream::VolumeCallback(pa_context* context,
+                                           const pa_source_info* info,
+                                           int error, void* user_data) {
+  PulseAudioInputStream* stream =
+      reinterpret_cast<PulseAudioInputStream*>(user_data);
+
+  if (error) {
+    pa_threaded_mainloop_signal(stream->pa_mainloop_, 0);
+    return;
+  }
+
+  if (stream->channels_ != info->channel_map.channels)
+    stream->channels_ = info->channel_map.channels;
+
+  pa_volume_t volume = PA_VOLUME_MUTED; // Minimum possible value.
+  // Use the max volume of any channel as the volume.
+  for (int i = 0; i < stream->channels_; ++i) {
+    if (volume < info->volume.values[i])
+      volume = info->volume.values[i];
+  }
+
+  stream->volume_ = static_cast<double>(volume);
+}
+
+// static, used by pa_stream_set_state_callback.
+void PulseAudioInputStream::StreamNotifyCallback(pa_stream* stream,
+                                                 void* user_data) {
+  PulseAudioInputStream* pulse_stream =
+      reinterpret_cast<PulseAudioInputStream*>(user_data);
+  if (stream && pulse_stream->callback_ &&
+      pa_stream_get_state(stream) == PA_STREAM_FAILED) {
+    pulse_stream->callback_->OnError(
+        pulse_stream, pa_context_errno(pulse_stream->pa_context_));
+  }
+
+  pa_threaded_mainloop_signal(pulse_stream->pa_mainloop_, 0);
+}
+
+void PulseAudioInputStream::ReadData() {
+  uint32 hardware_delay = GetHardwareLatencyInBytes(
+      handle_, params_.sample_rate(), params_.GetBytesPerFrame());
+
+  // Update the AGC volume level once every second. Note that,
+  // |volume| is also updated each time SetVolume() is called
+  // through IPC by the render-side AGC.
+  double normalized_volume = 0.0;
+  QueryAgcVolume(&normalized_volume);
+
+  while (true) {
+    size_t length = 0;
+    const void* data = NULL;
+    pa_stream_peek(handle_, &data, &length);
+    if (!data || length == 0)
+      break;
+
+    buffer_->Append(reinterpret_cast<const uint8*>(data), length);
+
+    // Checks if we still have data.
+    pa_stream_drop(handle_);
+    if (pa_stream_readable_size(handle_) <= 0)
+      break;
+  }
+
+  int packet_size = params_.GetBytesPerBuffer();
+  while (buffer_->forward_bytes() >= packet_size) {
+    buffer_->Read(audio_data_buffer_.get(), packet_size);
+    callback_->OnData(this, audio_data_buffer_.get(),  packet_size,
+                      hardware_delay, normalized_volume);
+
+    if (buffer_->forward_bytes() < packet_size)
+      break;
+
+    // TODO(xians): improve the code by implementing a WaitTillDataReady on the
+    // input side.
+    DLOG(WARNING) << "OnData is being called consecutively, sleep 2ms to "
+                  << "wait until render consumes the data";
+    base::PlatformThread::Sleep(
+        base::TimeDelta::FromMilliseconds(2));
+  }
+
+  pa_threaded_mainloop_signal(pa_mainloop_, 0);
+}
+
+}  // namespace media