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 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
