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      1 // Copyright 2013 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 "media/audio/cras/audio_manager_cras.h"
      6 
      7 #include "base/command_line.h"
      8 #include "base/environment.h"
      9 #include "base/logging.h"
     10 #include "base/nix/xdg_util.h"
     11 #include "base/stl_util.h"
     12 #include "media/audio/audio_util.h"
     13 #include "media/audio/cras/cras_input.h"
     14 #include "media/audio/cras/cras_unified.h"
     15 #include "media/base/channel_layout.h"
     16 
     17 namespace media {
     18 
     19 // Maximum number of output streams that can be open simultaneously.
     20 static const int kMaxOutputStreams = 50;
     21 
     22 // Default sample rate for input and output streams.
     23 static const int kDefaultSampleRate = 48000;
     24 
     25 const char AudioManagerCras::kLoopbackDeviceId[] = "loopback";
     26 
     27 bool AudioManagerCras::HasAudioOutputDevices() {
     28   return true;
     29 }
     30 
     31 bool AudioManagerCras::HasAudioInputDevices() {
     32   return true;
     33 }
     34 
     35 AudioManagerCras::AudioManagerCras() {
     36   SetMaxOutputStreamsAllowed(kMaxOutputStreams);
     37 }
     38 
     39 AudioManagerCras::~AudioManagerCras() {
     40   Shutdown();
     41 }
     42 
     43 void AudioManagerCras::ShowAudioInputSettings() {
     44   NOTIMPLEMENTED();
     45 }
     46 
     47 void AudioManagerCras::GetAudioInputDeviceNames(
     48     media::AudioDeviceNames* device_names) {
     49   DCHECK(device_names->empty());
     50   GetCrasAudioInputDevices(device_names);
     51   return;
     52 }
     53 
     54 AudioParameters AudioManagerCras::GetInputStreamParameters(
     55     const std::string& device_id) {
     56   static const int kDefaultInputBufferSize = 1024;
     57   // TODO(hshi): Fine-tune audio parameters based on |device_id|. The optimal
     58   // parameters for the loopback stream may differ from the default.
     59   return AudioParameters(
     60       AudioParameters::AUDIO_PCM_LOW_LATENCY, CHANNEL_LAYOUT_STEREO,
     61       kDefaultSampleRate, 16, kDefaultInputBufferSize);
     62 }
     63 
     64 void AudioManagerCras::GetCrasAudioInputDevices(
     65     media::AudioDeviceNames* device_names) {
     66   // Cras will route audio from a proper physical device automatically.
     67   device_names->push_back(
     68       AudioDeviceName(AudioManagerBase::kDefaultDeviceName,
     69                       AudioManagerBase::kDefaultDeviceId));
     70 }
     71 
     72 AudioOutputStream* AudioManagerCras::MakeLinearOutputStream(
     73     const AudioParameters& params) {
     74   DCHECK_EQ(AudioParameters::AUDIO_PCM_LINEAR, params.format());
     75   return MakeOutputStream(params);
     76 }
     77 
     78 AudioOutputStream* AudioManagerCras::MakeLowLatencyOutputStream(
     79     const AudioParameters& params, const std::string& input_device_id) {
     80   DCHECK_EQ(AudioParameters::AUDIO_PCM_LOW_LATENCY, params.format());
     81   // TODO(dgreid): Open the correct input device for unified IO.
     82   return MakeOutputStream(params);
     83 }
     84 
     85 AudioInputStream* AudioManagerCras::MakeLinearInputStream(
     86     const AudioParameters& params, const std::string& device_id) {
     87   DCHECK_EQ(AudioParameters::AUDIO_PCM_LINEAR, params.format());
     88   return MakeInputStream(params, device_id);
     89 }
     90 
     91 AudioInputStream* AudioManagerCras::MakeLowLatencyInputStream(
     92     const AudioParameters& params, const std::string& device_id) {
     93   DCHECK_EQ(AudioParameters::AUDIO_PCM_LOW_LATENCY, params.format());
     94   return MakeInputStream(params, device_id);
     95 }
     96 
     97 AudioParameters AudioManagerCras::GetPreferredOutputStreamParameters(
     98     const AudioParameters& input_params) {
     99   static const int kDefaultOutputBufferSize = 512;
    100 
    101   ChannelLayout channel_layout = CHANNEL_LAYOUT_STEREO;
    102   int sample_rate = kDefaultSampleRate;
    103   int buffer_size = kDefaultOutputBufferSize;
    104   int bits_per_sample = 16;
    105   int input_channels = 0;
    106   if (input_params.IsValid()) {
    107     sample_rate = input_params.sample_rate();
    108     bits_per_sample = input_params.bits_per_sample();
    109     channel_layout = input_params.channel_layout();
    110     input_channels = input_params.input_channels();
    111     buffer_size = input_params.frames_per_buffer();
    112   }
    113 
    114   int user_buffer_size = GetUserBufferSize();
    115   if (user_buffer_size)
    116     buffer_size = user_buffer_size;
    117 
    118   return AudioParameters(
    119       AudioParameters::AUDIO_PCM_LOW_LATENCY, channel_layout, input_channels,
    120       sample_rate, bits_per_sample, buffer_size);
    121 }
    122 
    123 AudioOutputStream* AudioManagerCras::MakeOutputStream(
    124     const AudioParameters& params) {
    125   return new CrasUnifiedStream(params, this);
    126 }
    127 
    128 AudioInputStream* AudioManagerCras::MakeInputStream(
    129     const AudioParameters& params, const std::string& device_id) {
    130   return new CrasInputStream(params, this, device_id);
    131 }
    132 
    133 }  // namespace media
    134