Home | History | Annotate | Download | only in host 
      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
     94