chromecast/media/audio/cast_audio_manager.cc

   1 // Copyright 2015 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 "chromecast/media/audio/cast_audio_manager.h"
   6
   7 #include "chromecast/base/task_runner_impl.h"
   8 #include "chromecast/media/audio/cast_audio_output_stream.h"
   9 #include "chromecast/public/cast_media_shlib.h"
  10 #include "chromecast/public/media/media_pipeline_backend.h"
  11 #include "chromecast/public/media/media_pipeline_device_params.h"
  12
  13 namespace {
  14 // TODO(alokp): Query the preferred value from media backend.
  15 const int kDefaultSampleRate = 48000;
  16
  17 // Define bounds for the output buffer size (in frames).
  18 // Note: These values are copied from AudioManagerPulse implementation.
  19 // TODO(alokp): Query the preferred value from media backend.
  20 static const int kMinimumOutputBufferSize = 512;
  21 static const int kMaximumOutputBufferSize = 8192;
  22 static const int kDefaultOutputBufferSize = 2048;
  23 }  // namespace
  24
  25 namespace chromecast {
  26 namespace media {
  27
  28 CastAudioManager::CastAudioManager(::media::AudioLogFactory* audio_log_factory)
  29     : AudioManagerBase(audio_log_factory) {}
  30
  31 CastAudioManager::~CastAudioManager() {
  32   Shutdown();
  33 }
  34
  35 bool CastAudioManager::HasAudioOutputDevices() {
  36   return true;
  37 }
  38
  39 bool CastAudioManager::HasAudioInputDevices() {
  40   return false;
  41 }
  42
  43 void CastAudioManager::ShowAudioInputSettings() {
  44   LOG(WARNING) << "No support for input audio devices";
  45 }
  46
  47 void CastAudioManager::GetAudioInputDeviceNames(
  48     ::media::AudioDeviceNames* device_names) {
  49   DCHECK(device_names->empty());
  50   LOG(WARNING) << "No support for input audio devices";
  51 }
  52
  53 ::media::AudioParameters CastAudioManager::GetInputStreamParameters(
  54     const std::string& device_id) {
  55   LOG(WARNING) << "No support for input audio devices";
  56   // Need to send a valid AudioParameters object even when it will unused.
  57   return ::media::AudioParameters(
  58       ::media::AudioParameters::AUDIO_PCM_LOW_LATENCY,
  59       ::media::CHANNEL_LAYOUT_STEREO, 48000, 16, 1024);
  60 }
  61
  62 scoped_ptr<MediaPipelineBackend>
  63 CastAudioManager::CreateMediaPipelineBackend() {
  64   DCHECK(GetTaskRunner()->BelongsToCurrentThread());
  65
  66   if (!audio_task_runner_)
  67     audio_task_runner_.reset(new TaskRunnerImpl());
  68
  69   MediaPipelineDeviceParams device_params(
  70       MediaPipelineDeviceParams::kModeIgnorePts, audio_task_runner_.get());
  71   return scoped_ptr<MediaPipelineBackend>(
  72       CastMediaShlib::CreateMediaPipelineBackend(device_params));
  73 }
  74
  75 ::media::AudioOutputStream* CastAudioManager::MakeLinearOutputStream(
  76     const ::media::AudioParameters& params) {
  77   DCHECK_EQ(::media::AudioParameters::AUDIO_PCM_LINEAR, params.format());
  78   return new CastAudioOutputStream(params, this);
  79 }
  80
  81 ::media::AudioOutputStream* CastAudioManager::MakeLowLatencyOutputStream(
  82     const ::media::AudioParameters& params,
  83     const std::string& device_id) {
  84   DCHECK_EQ(::media::AudioParameters::AUDIO_PCM_LOW_LATENCY, params.format());
  85   return new CastAudioOutputStream(params, this);
  86 }
  87
  88 ::media::AudioInputStream* CastAudioManager::MakeLinearInputStream(
  89     const ::media::AudioParameters& params,
  90     const std::string& device_id) {
  91   LOG(WARNING) << "No support for input audio devices";
  92   return nullptr;
  93 }
  94
  95 ::media::AudioInputStream* CastAudioManager::MakeLowLatencyInputStream(
  96     const ::media::AudioParameters& params,
  97     const std::string& device_id) {
  98   LOG(WARNING) << "No support for input audio devices";
  99   return nullptr;
 100 }
 101
 102 ::media::AudioParameters CastAudioManager::GetPreferredOutputStreamParameters(
 103     const std::string& output_device_id,
 104     const ::media::AudioParameters& input_params) {
 105   ::media::ChannelLayout channel_layout = ::media::CHANNEL_LAYOUT_STEREO;
 106   int sample_rate = kDefaultSampleRate;
 107   int buffer_size = kDefaultOutputBufferSize;
 108   int bits_per_sample = 16;
 109   if (input_params.IsValid()) {
 110     // Do not change:
 111     // - the channel layout
 112     // - the number of bits per sample
 113     // We support stereo only with 16 bits per sample.
 114     sample_rate = input_params.sample_rate();
 115     buffer_size = std::min(
 116         kMaximumOutputBufferSize,
 117         std::max(kMinimumOutputBufferSize, input_params.frames_per_buffer()));
 118   }
 119
 120   ::media::AudioParameters output_params(
 121       ::media::AudioParameters::AUDIO_PCM_LOW_LATENCY, channel_layout,
 122       sample_rate, bits_per_sample, buffer_size);
 123   return output_params;
 124 }
 125
 126 }  // namespace media
 127 }  // namespace chromecast