Allow AudioManagerCras enumerate audio devices from CRAS not just defaults

media/audio/cras/audio_manager_cras.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "media/audio/cras/audio_manager_cras.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 
 #include "base/command_line.h"
 #include "base/environment.h"
 #include "base/logging.h"
 #include "base/metrics/field_trial.h"
 #include "base/metrics/histogram.h"
 #include "base/nix/xdg_util.h"
 #include "base/stl_util.h"
+#include "base/strings/string_number_conversions.h"
 #include "chromeos/audio/audio_device.h"
 #include "chromeos/audio/cras_audio_handler.h"
 #include "media/audio/audio_device_description.h"
 #include "media/audio/cras/cras_input.h"
 #include "media/audio/cras/cras_unified.h"
 #include "media/base/channel_layout.h"
 #include "media/base/media_resources.h"
 
 // cras_util.h headers pull in min/max macros...
 // TODO(dgreid): Fix headers such that these aren't imported.
@@ skipping 30 matching lines @@
 void RecordBeamformingDeviceState(CrosBeamformingDeviceState state) {
   UMA_HISTOGRAM_ENUMERATION("Media.CrosBeamformingDeviceState", state,
                             BEAMFORMING_STATE_MAX + 1);
 }
 
 bool IsBeamformingDefaultEnabled() {
   return base::FieldTrialList::FindFullName("ChromebookBeamforming") ==
          "Enabled";
 }
 
-void AddDefaultDevice(AudioDeviceNames* device_names) {
-  DCHECK(device_names->empty());
-
-  // Cras will route audio from a proper physical device automatically.
-  device_names->push_back(AudioDeviceName::CreateDefault());
-}
-
 // Returns a mic positions string if the machine has a beamforming capable
 // internal mic and otherwise an empty string.
 std::string MicPositions() {
   // Get the list of devices from CRAS. An internal mic with a non-empty
   // positions field indicates the machine has a beamforming capable mic array.
   chromeos::AudioDeviceList devices;
   chromeos::CrasAudioHandler::Get()->GetAudioDevices(&devices);
   for (const auto& device : devices) {
     if (device.type == chromeos::AUDIO_TYPE_INTERNAL_MIC) {
       // There should be only one internal mic device.
@@ skipping 63 matching lines @@
 }
 
 AudioManagerCras::~AudioManagerCras() {
   Shutdown();
 }
 
 void AudioManagerCras::ShowAudioInputSettings() {
   NOTIMPLEMENTED();
 }
 
+void AudioManagerCras::GetAudioDeviceNamesImpl(bool is_input,
+                                               AudioDeviceNames* device_names) {
+  DCHECK(device_names->empty());
+  // At least two mic positions indicates we have a beamforming capable mic
+  // array. Add the virtual beamforming device to the list. When this device is
+  // queried through GetInputStreamParameters, provide the cached mic positions.
+  bool should_add_beamforming_devices = is_input && mic_positions_.size() > 1;
+  if (should_add_beamforming_devices)
+    AddBeamformingDevices(device_names);
+  chromeos::AudioDeviceList devices;
+  chromeos::CrasAudioHandler::Get()->GetAudioDevices(&devices);
+  for (const auto& device : devices) {
+    if (device.is_input == is_input && device.is_for_simple_usage()) {
+      media::AudioDeviceName device_name;
+      device_name.device_name = device.device_name;
+      device_name.unique_id = base::Uint64ToString(device.id);
+      device_names->push_back(device_name);

[DaleCurtis, 2016/07/06 18:58:52]

Does emplace_back(device.device_name, base::Uint64ToString(device.id)) work?

[Qiang(Joe) Xu, 2016/07/07 00:32:45]

done. tks.

+    }
+  }
+  if (!device_names->empty() && !should_add_beamforming_devices) {
+    device_names->push_front(media::AudioDeviceName::CreateDefault());

[DaleCurtis, 2016/07/06 18:58:53]

Just do this first to avoid push_front?

[Qiang(Joe) Xu, 2016/07/07 00:32:45]

done. tks.

+  }
+}
+
 void AudioManagerCras::GetAudioInputDeviceNames(
     AudioDeviceNames* device_names) {
-  DCHECK(device_names->empty());
-
   mic_positions_ = ParsePointsFromString(MicPositions());
-  // At least two mic positions indicates we have a beamforming capable mic
-  // array. Add the virtual beamforming device to the list. When this device is
-  // queried through GetInputStreamParameters, provide the cached mic positions.
-  if (mic_positions_.size() > 1)
-    AddBeamformingDevices(device_names);
-  else
-    AddDefaultDevice(device_names);
+  GetAudioDeviceNamesImpl(true, device_names);
 }
 
 void AudioManagerCras::GetAudioOutputDeviceNames(
     AudioDeviceNames* device_names) {
-  AddDefaultDevice(device_names);
+  GetAudioDeviceNamesImpl(false, device_names);
 }
 
 AudioParameters AudioManagerCras::GetInputStreamParameters(
     const std::string& device_id) {
   DCHECK(GetTaskRunner()->BelongsToCurrentThread());
 
   int user_buffer_size = GetUserBufferSize();
   int buffer_size = user_buffer_size ?
       user_buffer_size : kDefaultInputBufferSize;
 
@@ skipping 111 matching lines @@
     case 24:
       return SND_PCM_FORMAT_S24;
     case 32:
       return SND_PCM_FORMAT_S32;
     default:
       return SND_PCM_FORMAT_UNKNOWN;
   }
 }
 
 }  // namespace media