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Diffstat (limited to '')
-rw-r--r-- | third_party/libwebrtc/modules/audio_processing/echo_detector/normalized_covariance_estimator.cc | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/third_party/libwebrtc/modules/audio_processing/echo_detector/normalized_covariance_estimator.cc b/third_party/libwebrtc/modules/audio_processing/echo_detector/normalized_covariance_estimator.cc new file mode 100644 index 0000000000..8ec9fe9f0b --- /dev/null +++ b/third_party/libwebrtc/modules/audio_processing/echo_detector/normalized_covariance_estimator.cc @@ -0,0 +1,43 @@ +/* + * 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 |