Let default device in PulseAudio be the system default device

media/audio/pulse/pulse_util.cc

Index: media/audio/pulse/pulse_util.cc
diff --git a/media/audio/pulse/pulse_util.cc b/media/audio/pulse/pulse_util.cc
index 5044fa4d26eb4ab76dce0811433a8fb11d298299..ebefe914f19a4f8cbd4c884684d227a957037e59 100644
--- a/media/audio/pulse/pulse_util.cc
+++ b/media/audio/pulse/pulse_util.cc
@@ -11,6 +11,8 @@
 #include "base/time/time.h"
 #include "media/audio/audio_manager_base.h"
 #include "media/audio/audio_parameters.h"
+#include "media/audio/pulse/pulse_input.h"
+#include "media/base/limits.h"
 
 namespace media {
 
@@ -161,6 +163,34 @@ int GetHardwareLatencyInBytes(pa_stream* stream,
   } \
 } while (0)
 
+void SystemDefaultInputDeviceCallback(pa_context* context,
+                                      const pa_server_info* info,
+                                      void* user_data) {
+  PulseAudioInputStream* stream =
+      reinterpret_cast<PulseAudioInputStream*>(user_data);
+  stream->device_name_ = info->default_source_name;

[Henrik Grunell, 2016/02/24 15:54:53]

This will overwrite the device name provided in the stream ctor, which will
break how things should work. If the default device should be used,
|stream->device_name_| will be "default". When overwritten that device will be
used going forward, even if the default changes.

Looking closer at this, instead move getting the system default device name into
PulseAudioInputStream::Open(). There first check if |device_name_| ==
AudioManagerBase::kDefaultDeviceId. If yes get the system default device name
and use that when calling CreateInputStream(). If no, use |device_name_|. These
two functions go there as ordinary functions in the cc file.

Same for output.

[rchtara, 2016/02/25 17:17:26]

Done.

+  pa_threaded_mainloop* pa_mainloop =
+      static_cast<pa_threaded_mainloop*>(stream->pa_mainloop_);
+  pa_threaded_mainloop_signal(pa_mainloop, 0);
+}
+
+std::string GetSystemDefaultInputDevice(pa_threaded_mainloop* mainloop,
+                                        pa_context* context) {
+  DCHECK(mainloop);
+  DCHECK(context);
+  AudioParameters params(AudioParameters::Format::AUDIO_PCM_LINEAR,
+                         ChannelLayout::CHANNEL_LAYOUT_MONO,
+                         limits::kMinSampleRate, limits::kMaxBitsPerSample,
+                         limits::kMaxSamplesPerPacket);
+
+  PulseAudioInputStream stream(NULL, "", params, mainloop, context);
+
+  pa_operation* operation = pa_context_get_server_info(
+      context, SystemDefaultInputDeviceCallback, &stream);
+  WaitForOperationCompletion(mainloop, operation);
+  return stream.device_name_;
+}
+
 bool CreateInputStream(pa_threaded_mainloop* mainloop,
                        pa_context* context,
                        pa_stream** stream,
@@ -206,17 +236,21 @@ bool CreateInputStream(pa_threaded_mainloop* mainloop,
   buffer_attributes.minreq = buffer_size;
   buffer_attributes.prebuf = static_cast<uint32_t>(-1);
   buffer_attributes.fragsize = buffer_size;
+
   int flags = PA_STREAM_AUTO_TIMING_UPDATE |
               PA_STREAM_INTERPOLATE_TIMING |
               PA_STREAM_ADJUST_LATENCY |
               PA_STREAM_START_CORKED;
+
+  std::string system_default_input_device =
+      GetSystemDefaultInputDevice(mainloop, context);
+
   RETURN_ON_FAILURE(
       pa_stream_connect_record(
-          *stream,
-          device_id == AudioManagerBase::kDefaultDeviceId ?
-              NULL : device_id.c_str(),
-          &buffer_attributes,
-          static_cast<pa_stream_flags_t>(flags)) == 0,
+          *stream, device_id == AudioManagerBase::kDefaultDeviceId

[Henrik Grunell, 2016/02/24 15:54:52]

Then here, always use |device_id|.

And below for input too.

[rchtara, 2016/02/25 17:17:26]

Done.

[rchtara, 2016/02/25 17:17:26]

Done.

+                       ? system_default_input_device.c_str()
+                       : device_id.c_str(),
+          &buffer_attributes, static_cast<pa_stream_flags_t>(flags)) == 0,
       "pa_stream_connect_record FAILED ");
 
   // Wait for the stream to be ready.
@@ -232,6 +266,35 @@ bool CreateInputStream(pa_threaded_mainloop* mainloop,
   return true;
 }
 
+void SystemDefaultOutputDeviceCallback(pa_context* context,
+                                       const pa_server_info* info,
+                                       void* user_data) {
+  PulseAudioInputStream* stream =
+      reinterpret_cast<PulseAudioInputStream*>(user_data);
+  stream->device_name_ = info->default_sink_name;
+  pa_threaded_mainloop* pa_mainloop =
+      static_cast<pa_threaded_mainloop*>(stream->pa_mainloop_);
+  pa_threaded_mainloop_signal(pa_mainloop, 0);
+}
+
+std::string GetSystemDefaultOutputDevice(pa_threaded_mainloop* mainloop,
+                                         pa_context* context) {
+  DCHECK(mainloop);
+  DCHECK(context);
+  AudioParameters params(AudioParameters::Format::AUDIO_PCM_LINEAR,
+                         ChannelLayout::CHANNEL_LAYOUT_MONO,
+                         limits::kMinSampleRate, limits::kMaxBitsPerSample,
+                         limits::kMaxSamplesPerPacket);
+
+  PulseAudioInputStream stream(NULL, "", params, mainloop, context);
+
+  pa_operation* operation = pa_context_get_server_info(
+      context, SystemDefaultOutputDeviceCallback, &stream);
+  WaitForOperationCompletion(mainloop, operation);
+  DLOG(WARNING) << "Operation is NU" << stream.device_name_;
+  return stream.device_name_;
+}
+
 bool CreateOutputStream(pa_threaded_mainloop** mainloop,
                         pa_context** context,
                         pa_stream** stream,
@@ -327,21 +390,23 @@ bool CreateOutputStream(pa_threaded_mainloop** mainloop,
   pa_buffer_attributes.tlength = params.GetBytesPerBuffer() * 3;
   pa_buffer_attributes.fragsize = static_cast<uint32_t>(-1);
 
+  std::string system_default_output_device =
+      GetSystemDefaultOutputDevice(*mainloop, *context);
+
   // Connect playback stream.  Like pa_buffer_attr, the pa_stream_flags have a
   // huge impact on the performance of the stream and were chosen through trial
   // and error.
   RETURN_ON_FAILURE(
       pa_stream_connect_playback(
-          *stream,
-          device_id == AudioManagerBase::kDefaultDeviceId ?
-              NULL : device_id.c_str(),
+          *stream, device_id == AudioManagerBase::kDefaultDeviceId
+                       ? system_default_output_device.c_str()
+                       : device_id.c_str(),
           &pa_buffer_attributes,
           static_cast<pa_stream_flags_t>(
               PA_STREAM_INTERPOLATE_TIMING | PA_STREAM_ADJUST_LATENCY |
               PA_STREAM_AUTO_TIMING_UPDATE | PA_STREAM_NOT_MONOTONIC |
               PA_STREAM_START_CORKED),
-          NULL,
-          NULL) == 0,
+          NULL, NULL) == 0,
       "pa_stream_connect_playback FAILED ");
 
   // Wait for the stream to be ready.