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Diffstat (limited to 'webrtc/modules/audio_processing/agc/gmm.h')
-rw-r--r-- | webrtc/modules/audio_processing/agc/gmm.h | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/webrtc/modules/audio_processing/agc/gmm.h b/webrtc/modules/audio_processing/agc/gmm.h new file mode 100644 index 0000000000..90ce95d4dd --- /dev/null +++ b/webrtc/modules/audio_processing/agc/gmm.h @@ -0,0 +1,45 @@ +/* + * Copyright (c) 2012 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. + */ + +#ifndef WEBRTC_MODULES_AUDIO_PROCESSING_AGC_GMM_H_ +#define WEBRTC_MODULES_AUDIO_PROCESSING_AGC_GMM_H_ + +namespace webrtc { + +// A structure that specifies a GMM. +// A GMM is formulated as +// f(x) = w[0] * mixture[0] + w[1] * mixture[1] + ... + +// w[num_mixtures - 1] * mixture[num_mixtures - 1]; +// Where a 'mixture' is a Gaussian density. + +struct GmmParameters { + // weight[n] = log(w[n]) - |dimension|/2 * log(2*pi) - 1/2 * log(det(cov[n])); + // where cov[n] is the covariance matrix of mixture n; + const double* weight; + // pointer to the first element of a |num_mixtures|x|dimension| matrix + // where kth row is the mean of the kth mixture. + const double* mean; + // pointer to the first element of a |num_mixtures|x|dimension|x|dimension| + // 3D-matrix, where the kth 2D-matrix is the inverse of the covariance + // matrix of the kth mixture. + const double* covar_inverse; + // Dimensionality of the mixtures. + int dimension; + // number of the mixtures. + int num_mixtures; +}; + +// Evaluate the given GMM, according to |gmm_parameters|, at the given point +// |x|. If the dimensionality of the given GMM is larger that the maximum +// acceptable dimension by the following function -1 is returned. +double EvaluateGmm(const double* x, const GmmParameters& gmm_parameters); + +} // namespace webrtc +#endif // WEBRTC_MODULES_AUDIO_PROCESSING_AGC_GMM_H_ |