Added a level controller initialization value to MediaConstraints.

webrtc/api/localaudiosource.cc

 /*
  *  Copyright 2013 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
 #include "webrtc/api/localaudiosource.h"
 
 #include <vector>
 
 #include "webrtc/api/mediaconstraintsinterface.h"
 #include "webrtc/media/base/mediaengine.h"
 
 using webrtc::MediaConstraintsInterface;
 using webrtc::MediaSourceInterface;
 
 namespace webrtc {
 
 namespace {
 
 // Convert constraints to audio options. Return false if constraints are
 // invalid.
 void FromConstraints(const MediaConstraintsInterface::Constraints& constraints,
                      cricket::AudioOptions* options) {
-  // This design relies on the fact that all the audio constraints are actually
-  // "options", i.e. boolean-valued and always satisfiable.  If the constraints
-  // are extended to include non-boolean values or actual format constraints,
-  // a different algorithm will be required.
+  // Set boolean constarints first.

[tommi, 2016/10/19 11:25:50]

Fix typo

[aleloi, 2016/10/19 13:59:21]

Done.

   struct {
     const char* name;
     rtc::Optional<bool>& value;
-  } key_to_value[] = {
+  } boolean_constraint_key_to_value[] = {

[tommi, 2016/10/19 11:25:50]

Are these changes relevant to the cl?
Maybe it's just fine to leave this part as it was, with the comment etc. As is,
having the new qualifier yet no other map, might just make it more confusing. 

[aleloi, 2016/10/19 13:59:21]

I agree, lets leave it as is.

       {MediaConstraintsInterface::kGoogEchoCancellation,
        options->echo_cancellation},
       {MediaConstraintsInterface::kExtendedFilterEchoCancellation,
        options->extended_filter_aec},
       {MediaConstraintsInterface::kDAEchoCancellation,
        options->delay_agnostic_aec},
       {MediaConstraintsInterface::kAutoGainControl, options->auto_gain_control},
       {MediaConstraintsInterface::kExperimentalAutoGainControl,
        options->experimental_agc},
       {MediaConstraintsInterface::kNoiseSuppression,
        options->noise_suppression},
       {MediaConstraintsInterface::kExperimentalNoiseSuppression,
        options->experimental_ns},
       {MediaConstraintsInterface::kIntelligibilityEnhancer,
        options->intelligibility_enhancer},
       {MediaConstraintsInterface::kLevelControl, options->level_control},
       {MediaConstraintsInterface::kHighpassFilter, options->highpass_filter},
       {MediaConstraintsInterface::kTypingNoiseDetection,
        options->typing_detection},
-      {MediaConstraintsInterface::kAudioMirroring, options->stereo_swapping}
-  };
+      {MediaConstraintsInterface::kAudioMirroring, options->stereo_swapping}};
 
   for (const auto& constraint : constraints) {
     bool value = false;
     if (!rtc::FromString(constraint.value, &value))
       continue;
 
-    for (auto& entry : key_to_value) {
+    for (auto& entry : boolean_constraint_key_to_value) {
       if (constraint.key.compare(entry.name) == 0)
         entry.value = rtc::Optional<bool>(value);
     }
   }
+
+  // Set non-boolean constraints.
+  std::string value;
+  if (constraints.FindFirst(
+          MediaConstraintsInterface::kLevelControlInitialPeakLevelDBFS,
+          &value)) {
+    float level_control_initial_peak_level_dbfs;
+    if (rtc::FromString(value, &level_control_initial_peak_level_dbfs)) {
+      options->level_control_initial_peak_level_dbfs =
+          rtc::Optional<float>(level_control_initial_peak_level_dbfs);
+    }
+  }
 }
 
 }  // namespace
 
 rtc::scoped_refptr<LocalAudioSource> LocalAudioSource::Create(
     const PeerConnectionFactoryInterface::Options& options,
     const MediaConstraintsInterface* constraints) {
   rtc::scoped_refptr<LocalAudioSource> source(
       new rtc::RefCountedObject<LocalAudioSource>());
   source->Initialize(options, constraints);
@@ skipping 27 matching lines @@
 void LocalAudioSource::Initialize(
     const PeerConnectionFactoryInterface::Options& options,
     const cricket::AudioOptions* audio_options) {
   if (!audio_options)
     return;
 
   options_ = *audio_options;
 }
 
 }  // namespace webrtc