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 
WebRtcSpl_GetScalingSquare(int16_t * in_vector,size_t in_vector_length,size_t times)20 int16_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