remoting/host/audio_capturer_linux.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "remoting/host/audio_capturer_linux.h"
   6
   7 #include "base/files/file_path.h"
   8 #include "base/lazy_instance.h"
   9 #include "base/logging.h"
  10 #include "remoting/proto/audio.pb.h"
  11
  12 namespace remoting {
  13
  14 namespace {
  15
  16 // PulseAudio's module-pipe-sink must be configured to use the following
  17 // parameters for the sink we read from.
  18 const AudioPacket_SamplingRate kSamplingRate = AudioPacket::SAMPLING_RATE_48000;
  19
  20 base::LazyInstance<scoped_refptr<AudioPipeReader> >::Leaky
  21     g_pulseaudio_pipe_sink_reader = LAZY_INSTANCE_INITIALIZER;
  22
  23 }  // namespace
  24
  25 // TODO(wez): Remove this and have the DesktopEnvironmentFactory own the
  26 // AudioPipeReader rather than having it process-global.
  27 // See crbug.com/161373 and crbug.com/104544.
  28 void AudioCapturerLinux::InitializePipeReader(
  29     scoped_refptr<base::SingleThreadTaskRunner> task_runner,
  30     const base::FilePath& pipe_name) {
  31   scoped_refptr<AudioPipeReader> pipe_reader;
  32   if (!pipe_name.empty())
  33     pipe_reader = AudioPipeReader::Create(task_runner, pipe_name);
  34   g_pulseaudio_pipe_sink_reader.Get() = pipe_reader;
  35 }
  36
  37 AudioCapturerLinux::AudioCapturerLinux(
  38     scoped_refptr<AudioPipeReader> pipe_reader)
  39     : pipe_reader_(pipe_reader),
  40       silence_detector_(0) {
  41 }
  42
  43 AudioCapturerLinux::~AudioCapturerLinux() {
  44 }
  45
  46 bool AudioCapturerLinux::Start(const PacketCapturedCallback& callback) {
  47   callback_ = callback;
  48   silence_detector_.Reset(kSamplingRate, AudioPacket::CHANNELS_STEREO);
  49   pipe_reader_->AddObserver(this);
  50   return true;
  51 }
  52
  53 void AudioCapturerLinux::Stop() {
  54   pipe_reader_->RemoveObserver(this);
  55   callback_.Reset();
  56 }
  57
  58 bool AudioCapturerLinux::IsStarted() {
  59   return !callback_.is_null();
  60 }
  61
  62 void AudioCapturerLinux::OnDataRead(
  63     scoped_refptr<base::RefCountedString> data) {
  64   DCHECK(!callback_.is_null());
  65
  66   if (silence_detector_.IsSilence(
  67           reinterpret_cast<const int16*>(data->data().data()),
  68           data->data().size() / sizeof(int16))) {
  69     return;
  70   }
  71
  72   scoped_ptr<AudioPacket> packet(new AudioPacket());
  73   packet->add_data(data->data());
  74   packet->set_encoding(AudioPacket::ENCODING_RAW);
  75   packet->set_sampling_rate(kSamplingRate);
  76   packet->set_bytes_per_sample(AudioPacket::BYTES_PER_SAMPLE_2);
  77   packet->set_channels(AudioPacket::CHANNELS_STEREO);
  78   callback_.Run(packet.Pass());
  79 }
  80
  81 bool AudioCapturer::IsSupported() {
  82   return g_pulseaudio_pipe_sink_reader.Get().get() != NULL;
  83 }
  84
  85 scoped_ptr<AudioCapturer> AudioCapturer::Create() {
  86   scoped_refptr<AudioPipeReader> reader =
  87       g_pulseaudio_pipe_sink_reader.Get();
  88   if (!reader.get())
  89     return scoped_ptr<AudioCapturer>();
  90   return scoped_ptr<AudioCapturer>(new AudioCapturerLinux(reader));
  91 }
  92
  93 }  // namespace remoting