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 iLBC Speech Coder ANSI-C Source Code 14 15 WebRtcIlbcfix_MyCorr.c 16 17******************************************************************/ 18 19#include "defines.h" 20 21/*----------------------------------------------------------------* 22 * compute cross correlation between sequences 23 *---------------------------------------------------------------*/ 24 25void WebRtcIlbcfix_MyCorr( 26 int32_t* corr, /* (o) correlation of seq1 and seq2 */ 27 const int16_t* seq1, /* (i) first sequence */ 28 size_t dim1, /* (i) dimension first seq1 */ 29 const int16_t* seq2, /* (i) second sequence */ 30 size_t dim2 /* (i) dimension seq2 */ 31 ){ 32 int16_t max; 33 size_t loops; 34 int scale; 35 36 /* Calculate correlation between the two sequences. Scale the 37 result of the multiplcication to maximum 26 bits in order 38 to avoid overflow */ 39 max=WebRtcSpl_MaxAbsValueW16(seq1, dim1); 40 scale=WebRtcSpl_GetSizeInBits(max); 41 42 scale = 2 * scale - 26; 43 if (scale<0) { 44 scale=0; 45 } 46 47 loops=dim1-dim2+1; 48 49 /* Calculate the cross correlations */ 50 WebRtcSpl_CrossCorrelation(corr, seq2, seq1, dim2, loops, scale, 1); 51 52 return; 53} 54