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 
WebRtcSpl_GetScalingSquare(WebRtc_Word16 * in_vector,int in_vector_length,int times)20 int 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