[Opus] Update to v1.2.1

media/cast/test/utility/audio_utility.cc

 // Copyright 2014 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 <cmath>
 #include <vector>
 
 #include "base/logging.h"
 #include "base/time/time.h"
 #include "media/base/audio_bus.h"
@@ skipping 26 matching lines @@
                                            base::TimeDelta::FromSeconds(1));
   std::unique_ptr<AudioBus> bus(AudioBus::Create(num_channels_, num_samples));
   source_.OnMoreData(base::TimeDelta(), base::TimeTicks::Now(), 0, bus.get());
   bus->Scale(volume_);
   return bus;
 }
 
 int CountZeroCrossings(const float* samples, int length) {
   // The sample values must pass beyond |kAmplitudeThreshold| on the opposite
   // side of zero before a crossing will be counted.
-  const float kAmplitudeThreshold = 0.03f;  // 3% of max amplitude.
+  const float kAmplitudeThreshold = 0.02f;  // 2% of max amplitude.
 
   int count = 0;
   int i = 0;
   float last = 0.0f;
   for (; i < length && fabsf(last) < kAmplitudeThreshold; ++i)
     last = samples[i];
   for (; i < length; ++i) {
     if (fabsf(samples[i]) >= kAmplitudeThreshold &&
         (last < 0) != (samples[i] < 0)) {
       ++count;
@@ skipping 122 matching lines @@
       }
       *timestamp = gray_coded;
       return true;
     }
   }
   return false;
 }
 
 }  // namespace cast
 }  // namespace media