1/*
2 *  Copyright (c) 2013 The WebRTC project authors. All Rights Reserved.
3 *
4 *  Use of this source code is governed by a BSD-style license
5 *  that can be found in the LICENSE file in the root of the source
6 *  tree. An additional intellectual property rights grant can be found
7 *  in the file PATENTS.  All contributing project authors may
8 *  be found in the AUTHORS file in the root of the source tree.
9 */
10
11#include "webrtc/modules/audio_processing/transient/moving_moments.h"
12
13#include <math.h>
14#include <string.h>
15
16#include "webrtc/base/scoped_ptr.h"
17
18namespace webrtc {
19
20MovingMoments::MovingMoments(size_t length)
21    : length_(length),
22      queue_(),
23      sum_(0.0),
24      sum_of_squares_(0.0) {
25  assert(length > 0);
26  for (size_t i = 0; i < length; ++i) {
27    queue_.push(0.0);
28  }
29}
30
31MovingMoments::~MovingMoments() {}
32
33void MovingMoments::CalculateMoments(const float* in, size_t in_length,
34                                     float* first, float* second) {
35  assert(in && in_length > 0 && first && second);
36
37  for (size_t i = 0; i < in_length; ++i) {
38    const float old_value = queue_.front();
39    queue_.pop();
40    queue_.push(in[i]);
41
42    sum_ += in[i] - old_value;
43    sum_of_squares_ += in[i] * in[i] - old_value * old_value;
44    first[i] = sum_ / length_;
45    second[i] = sum_of_squares_ / length_;
46  }
47}
48
49}  // namespace webrtc
50