blob: 8ec9fe9f0b5ed95f6b2c0231304d5143457533d0 [file] [log] [blame]
/*
* 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/normalized_covariance_estimator.h"
#include <math.h>
#include "rtc_base/checks.h"
namespace webrtc {
namespace {
// Parameter controlling the adaptation speed.
constexpr float kAlpha = 0.001f;
} // namespace
void NormalizedCovarianceEstimator::Update(float x,
float x_mean,
float x_sigma,
float y,
float y_mean,
float y_sigma) {
covariance_ =
(1.f - kAlpha) * covariance_ + kAlpha * (x - x_mean) * (y - y_mean);
normalized_cross_correlation_ = covariance_ / (x_sigma * y_sigma + .0001f);
RTC_DCHECK(isfinite(covariance_));
RTC_DCHECK(isfinite(normalized_cross_correlation_));
}
void NormalizedCovarianceEstimator::Clear() {
covariance_ = 0.f;
normalized_cross_correlation_ = 0.f;
}
} // namespace webrtc