| /* |
| * 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 WEBRTC_COMMON_AUDIO_VAD_VAD_GMM_H_ |
| #define WEBRTC_COMMON_AUDIO_VAD_VAD_GMM_H_ |
| |
| #include "webrtc/typedefs.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 // WEBRTC_COMMON_AUDIO_VAD_VAD_GMM_H_ |
