Let default device in PulseAudio be the system default device

media/audio/pulse/pulse_input.cc

 // Copyright (c) 2012 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/pulse/pulse_input.h"
 
 #include <stdint.h>
 
 #include "base/logging.h"
 #include "media/audio/pulse/audio_manager_pulse.h"
@@ skipping 30 matching lines @@
   DCHECK(context);
   CHECK(params_.IsValid());
 }
 
 PulseAudioInputStream::~PulseAudioInputStream() {
   // All internal structures should already have been freed in Close(),
   // which calls AudioManagerPulse::Release which deletes this object.
   DCHECK(!handle_);
 }
 
+// static, used by pa_context_get_server_info.
+void PulseAudioInputStream::GetSystemDefaultInputDeviceCallback(
+    pa_context* context,
+    const pa_server_info* info,
+    void* user_data) {
+  PulseAudioInputStream* stream =
+      reinterpret_cast<PulseAudioInputStream*>(user_data);
+  stream->default_system_device_name_ = info->default_source_name;

[Henrik Grunell, 2016/03/09 00:49:17]

Add setter function for |default_system_device_name_| and getter for
|pa_mainloop_|.

[rchtara, 2016/03/09 16:16:09]

Done.

+  pa_threaded_mainloop* pa_mainloop =
+      static_cast<pa_threaded_mainloop*>(stream->pa_mainloop_);

[Henrik Grunell, 2016/03/09 00:49:17]

It doesn't look like casting is needed here.

[rchtara, 2016/03/09 16:16:09]

Done.

+  pa_threaded_mainloop_signal(pa_mainloop, 0);
+}
+
+void PulseAudioInputStream::GetSystemDefaultInputDevice() {
+  DCHECK(pa_mainloop_);
+  DCHECK(pa_context_);
+  pa_operation* operation = pa_context_get_server_info(
+      pa_context_, PulseAudioInputStream::GetSystemDefaultInputDeviceCallback,
+      this);
+  WaitForOperationCompletion(pa_mainloop_, operation);
+}
+
 bool PulseAudioInputStream::Open() {
   DCHECK(thread_checker_.CalledOnValidThread());
   AutoPulseLock auto_lock(pa_mainloop_);
+  std::string device_to_use_ = device_name_;

[Henrik Grunell, 2016/03/09 00:49:17]

"device_to_use_" -> "device_name_to_use". (No trailing "_".)

[rchtara, 2016/03/09 16:16:09]

Done.

+  if (device_name_ == AudioManagerBase::kDefaultDeviceId) {
+    GetSystemDefaultInputDevice();
+    device_to_use_ = default_system_device_name_;
+  }
+
   if (!pulse::CreateInputStream(pa_mainloop_, pa_context_, &handle_, params_,
-                                device_name_, &StreamNotifyCallback, this)) {
+                                device_to_use_, &StreamNotifyCallback, this)) {
     return false;
   }
 
   DCHECK(handle_);
 
   return true;
 }
 
 void PulseAudioInputStream::Start(AudioInputCallback* callback) {
   DCHECK(thread_checker_.CalledOnValidThread());
@@ skipping 260 matching lines @@
     return false;
 
   size_t index = pa_stream_get_device_index(handle_);
   pa_operation* operation =
       pa_context_get_source_info_by_index(pa_context_, index, callback, this);
   WaitForOperationCompletion(pa_mainloop_, operation);
   return true;
 }
 
 }  // namespace media