54 lines
1.9 KiB
C++
54 lines
1.9 KiB
C++
/*
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* Copyright (c) 2013 The WebRTC project authors. All Rights Reserved.
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*
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* Use of this source code is governed by a BSD-style license
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* that can be found in the LICENSE file in the root of the source
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* tree. An additional intellectual property rights grant can be found
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* in the file PATENTS. All contributing project authors may
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* be found in the AUTHORS file in the root of the source tree.
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*/
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#ifndef MODULES_AUDIO_PROCESSING_TRANSIENT_MOVING_MOMENTS_H_
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#define MODULES_AUDIO_PROCESSING_TRANSIENT_MOVING_MOMENTS_H_
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#include <stddef.h>
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#include <queue>
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namespace webrtc {
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// Calculates the first and second moments for each value of a buffer taking
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// into account a given number of previous values.
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// It preserves its state, so it can be multiple-called.
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// TODO(chadan): Implement a function that takes a buffer of first moments and a
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// buffer of second moments; and calculates the variances. When needed.
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// TODO(chadan): Add functionality to update with a buffer but only output are
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// the last values of the moments. When needed.
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class MovingMoments {
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public:
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// Creates a Moving Moments object, that uses the last |length| values
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// (including the new value introduced in every new calculation).
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explicit MovingMoments(size_t length);
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~MovingMoments();
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// Calculates the new values using |in|. Results will be in the out buffers.
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// |first| and |second| must be allocated with at least |in_length|.
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void CalculateMoments(const float* in,
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size_t in_length,
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float* first,
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float* second);
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private:
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size_t length_;
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// A queue holding the |length_| latest input values.
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std::queue<float> queue_;
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// Sum of the values of the queue.
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float sum_;
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// Sum of the squares of the values of the queue.
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float sum_of_squares_;
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};
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} // namespace webrtc
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#endif // MODULES_AUDIO_PROCESSING_TRANSIENT_MOVING_MOMENTS_H_
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