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 "signal_processing_library.h"
19
20int WebRtcSpl_GetScalingSquare(WebRtc_Word16 *in_vector, int in_vector_length, int times)
21{
22    int nbits = WebRtcSpl_GetSizeInBits(times);
23    int i;
24    WebRtc_Word16 smax = -1;
25    WebRtc_Word16 sabs;
26    WebRtc_Word16 *sptr = in_vector;
27    int t;
28    int looptimes = in_vector_length;
29
30    for (i = looptimes; i > 0; i--)
31    {
32        sabs = (*sptr > 0 ? *sptr++ : -*sptr++);
33        smax = (sabs > smax ? sabs : smax);
34    }
35    t = WebRtcSpl_NormW32(WEBRTC_SPL_MUL(smax, smax));
36
37    if (smax == 0)
38    {
39        return 0; // Since norm(0) returns 0
40    } else
41    {
42        return (t > nbits) ? 0 : nbits - t;
43    }
44}
45