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 <stdint.h>
8 
9 #include <utility>
10 
11 #include "base/check.h"
12 #include "base/files/file_path.h"
13 #include "base/lazy_instance.h"
14 #include "base/memory/ptr_util.h"
15 #include "remoting/proto/audio.pb.h"
16 
17 namespace remoting {
18 
19 namespace {
20 
21 base::LazyInstance<scoped_refptr<AudioPipeReader>>::Leaky
22     g_pulseaudio_pipe_sink_reader = LAZY_INSTANCE_INITIALIZER;
23 
24 }  // namespace
25 
26 // TODO(wez): Remove this and have the DesktopEnvironmentFactory own the
27 // AudioPipeReader rather than having it process-global.
28 // See crbug.com/161373 and crbug.com/104544.
InitializePipeReader(scoped_refptr<base::SingleThreadTaskRunner> task_runner,const base::FilePath & pipe_name)29 void AudioCapturerLinux::InitializePipeReader(
30     scoped_refptr<base::SingleThreadTaskRunner> task_runner,
31     const base::FilePath& pipe_name) {
32   scoped_refptr<AudioPipeReader> pipe_reader;
33   if (!pipe_name.empty())
34     pipe_reader = AudioPipeReader::Create(task_runner, pipe_name);
35   g_pulseaudio_pipe_sink_reader.Get() = pipe_reader;
36 }
37 
AudioCapturerLinux(scoped_refptr<AudioPipeReader> pipe_reader)38 AudioCapturerLinux::AudioCapturerLinux(
39     scoped_refptr<AudioPipeReader> pipe_reader)
40     : pipe_reader_(pipe_reader),
41       silence_detector_(0) {
42 }
43 
~AudioCapturerLinux()44 AudioCapturerLinux::~AudioCapturerLinux() {
45   pipe_reader_->RemoveObserver(this);
46 }
47 
Start(const PacketCapturedCallback & callback)48 bool AudioCapturerLinux::Start(const PacketCapturedCallback& callback) {
49   callback_ = callback;
50   silence_detector_.Reset(AudioPipeReader::kSamplingRate,
51                           AudioPipeReader::kChannels);
52   pipe_reader_->AddObserver(this);
53   return true;
54 }
55 
OnDataRead(scoped_refptr<base::RefCountedString> data)56 void AudioCapturerLinux::OnDataRead(
57     scoped_refptr<base::RefCountedString> data) {
58   DCHECK(!callback_.is_null());
59 
60   if (silence_detector_.IsSilence(
61           reinterpret_cast<const int16_t*>(data->data().data()),
62           data->data().size() / sizeof(int16_t) / AudioPipeReader::kChannels)) {
63     return;
64   }
65 
66   std::unique_ptr<AudioPacket> packet(new AudioPacket());
67   packet->add_data(data->data());
68   packet->set_encoding(AudioPacket::ENCODING_RAW);
69   packet->set_sampling_rate(AudioPipeReader::kSamplingRate);
70   packet->set_bytes_per_sample(AudioPipeReader::kBytesPerSample);
71   packet->set_channels(AudioPipeReader::kChannels);
72   callback_.Run(std::move(packet));
73 }
74 
IsSupported()75 bool AudioCapturer::IsSupported() {
76   return g_pulseaudio_pipe_sink_reader.Get().get() != nullptr;
77 }
78 
Create()79 std::unique_ptr<AudioCapturer> AudioCapturer::Create() {
80   scoped_refptr<AudioPipeReader> reader =
81       g_pulseaudio_pipe_sink_reader.Get();
82   if (!reader.get())
83     return nullptr;
84   return base::WrapUnique(new AudioCapturerLinux(reader));
85 }
86 
87 }  // namespace remoting
88