1/*
2 *  Copyright (c) 2011 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
12/*
13 * This file contains the function WebRtcSpl_GetScalingSquare().
14 * The description header can be found in signal_processing_library.h
15 *
16 */
17
18#include "webrtc/common_audio/signal_processing/include/signal_processing_library.h"
19
20int16_t WebRtcSpl_GetScalingSquare(int16_t* in_vector,
21                                   size_t in_vector_length,
22                                   size_t times)
23{
24    int16_t nbits = WebRtcSpl_GetSizeInBits((uint32_t)times);
25    size_t i;
26    int16_t smax = -1;
27    int16_t sabs;
28    int16_t *sptr = in_vector;
29    int16_t t;
30    size_t looptimes = in_vector_length;
31
32    for (i = looptimes; i > 0; i--)
33    {
34        sabs = (*sptr > 0 ? *sptr++ : -*sptr++);
35        smax = (sabs > smax ? sabs : smax);
36    }
37    t = WebRtcSpl_NormW32(WEBRTC_SPL_MUL(smax, smax));
38
39    if (smax == 0)
40    {
41        return 0; // Since norm(0) returns 0
42    } else
43    {
44        return (t > nbits) ? 0 : nbits - t;
45    }
46}
47