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/*
* Copyright (c) 2011 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.
*/
// Gaussian probability calculations internally used in vad_core.c.
#ifndef COMMON_AUDIO_VAD_VAD_GMM_H_
#define COMMON_AUDIO_VAD_VAD_GMM_H_
#include <stdint.h>
// Calculates the probability for |input|, given that |input| comes from a
// normal distribution with mean and standard deviation (|mean|, |std|).
//
// Inputs:
// - input : input sample in Q4.
// - mean : mean input in the statistical model, Q7.
// - std : standard deviation, Q7.
//
// Output:
//
// - delta : input used when updating the model, Q11.
// |delta| = (|input| - |mean|) / |std|^2.
//
// Return:
// (probability for |input|) =
// 1 / |std| * exp(-(|input| - |mean|)^2 / (2 * |std|^2));
int32_t WebRtcVad_GaussianProbability(int16_t input,
int16_t mean,
int16_t std,
int16_t* delta);
#endif // COMMON_AUDIO_VAD_VAD_GMM_H_
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