| /* |
| * 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 "webrtc/modules/audio_processing/echo_detector/normalized_covariance_estimator.h" |
| |
| #include <math.h> |
| |
| #include "webrtc/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 |