Switch to keyboard mic layout for WebRTC if conditions are met.

content/renderer/media/webrtc_audio_capturer.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 "content/renderer/media/webrtc_audio_capturer.h"
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
 #include "base/strings/string_util.h"
@@ skipping 138 matching lines @@
     return true;
   }
 
   MediaAudioConstraints audio_constraints(constraints_,
                                           device_info_.device.input.effects);
   if (!audio_constraints.IsValid())
     return false;
 
   media::ChannelLayout channel_layout = static_cast<media::ChannelLayout>(
       device_info_.device.input.channel_layout);
+
+  // If KEYBOARD_MIC effect is set, change the layout to the corresponding
+  // layout that includes the keyboard mic.
+  if (MediaStreamAudioProcessor::IsAudioTrackProcessingEnabled() &&
+      audio_constraints.GetProperty(
+          MediaAudioConstraints::kGoogExperimentalNoiseSuppression) &&
+      (device_info_.device.input.effects &
+       media::AudioParameters::KEYBOARD_MIC)) {

[tommi (sloooow) - chröme, 2014/09/23 17:27:00]

nit: this seems like the fastest condition to be checking. make first?

[Henrik Grunell, 2014/09/25 10:08:36]

Done.

+    if (channel_layout == media::CHANNEL_LAYOUT_STEREO) {
+      channel_layout = media::CHANNEL_LAYOUT_STEREO_AND_KEYBOARD_MIC;
+      DVLOG(1) << "Changed stereo layout to stereo + keyboard mic layout due "
+               << "to KEYBOARD_MIC effect.";
+    } else {
+      DVLOG(1) << "KEYBOARD_MIC effect ignored, not compatible with layout "
+               << channel_layout;
+    }
+  }
+
   DVLOG(1) << "Audio input hardware channel layout: " << channel_layout;
   UMA_HISTOGRAM_ENUMERATION("WebRTC.AudioInputChannelLayout",
                             channel_layout, media::CHANNEL_LAYOUT_MAX + 1);
 
   // Verify that the reported input channel configuration is supported.
   if (channel_layout != media::CHANNEL_LAYOUT_MONO &&
       channel_layout != media::CHANNEL_LAYOUT_STEREO &&
       channel_layout != media::CHANNEL_LAYOUT_STEREO_AND_KEYBOARD_MIC) {
     DLOG(ERROR) << channel_layout
                 << " is not a supported input channel configuration.";
@@ skipping 413 matching lines @@
 
 void WebRtcAudioCapturer::SetCapturerSourceForTesting(
     const scoped_refptr<media::AudioCapturerSource>& source,
     media::AudioParameters params) {
   // Create a new audio stream as source which uses the new source.
   SetCapturerSource(source, params.channel_layout(),
                     static_cast<float>(params.sample_rate()));
 }
 
 }  // namespace content