diff options
Diffstat (limited to 'third_party/libwebrtc/modules/audio_processing/echo_detector/mean_variance_estimator.cc')
-rw-r--r-- | third_party/libwebrtc/modules/audio_processing/echo_detector/mean_variance_estimator.cc | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/third_party/libwebrtc/modules/audio_processing/echo_detector/mean_variance_estimator.cc b/third_party/libwebrtc/modules/audio_processing/echo_detector/mean_variance_estimator.cc new file mode 100644 index 0000000000..a9ebb8cd92 --- /dev/null +++ b/third_party/libwebrtc/modules/audio_processing/echo_detector/mean_variance_estimator.cc @@ -0,0 +1,47 @@ +/* + * Copyright (c) 2016 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 "modules/audio_processing/echo_detector/mean_variance_estimator.h" + +#include <cmath> + +#include "rtc_base/checks.h" + +namespace webrtc { +namespace { + +// Parameter controlling the adaptation speed. +constexpr float kAlpha = 0.001f; + +} // namespace + +void MeanVarianceEstimator::Update(float value) { + mean_ = (1.f - kAlpha) * mean_ + kAlpha * value; + variance_ = + (1.f - kAlpha) * variance_ + kAlpha * (value - mean_) * (value - mean_); + RTC_DCHECK(std::isfinite(mean_)); + RTC_DCHECK(std::isfinite(variance_)); +} + +float MeanVarianceEstimator::std_deviation() const { + RTC_DCHECK_GE(variance_, 0.f); + return sqrtf(variance_); +} + +float MeanVarianceEstimator::mean() const { + return mean_; +} + +void MeanVarianceEstimator::Clear() { + mean_ = 0.f; + variance_ = 0.f; +} + +} // namespace webrtc |