1b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org/* 2b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org * Copyright (c) 2011 The WebRTC project authors. All Rights Reserved. 3b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org * 4b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org * Use of this source code is governed by a BSD-style license 5b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org * that can be found in the LICENSE file in the root of the source 6b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org * tree. An additional intellectual property rights grant can be found 7b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org * in the file PATENTS. All contributing project authors may 8b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org * be found in the AUTHORS file in the root of the source tree. 9b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org */ 10b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 11b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org/****************************************************************** 12b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 13b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org iLBC Speech Coder ANSI-C Source Code 14b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 15b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org WebRtcIlbcfix_MyCorr.c 16b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 17b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org******************************************************************/ 18b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 19b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org#include "defines.h" 20b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 21b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org/*----------------------------------------------------------------* 22b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org * compute cross correlation between sequences 23b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org *---------------------------------------------------------------*/ 24b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 25b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.orgvoid WebRtcIlbcfix_MyCorr( 26fbda0fcf2f9e82c82bcaac138f44d4e5144f6e0dpbos@webrtc.org int32_t *corr, /* (o) correlation of seq1 and seq2 */ 27fbda0fcf2f9e82c82bcaac138f44d4e5144f6e0dpbos@webrtc.org int16_t *seq1, /* (i) first sequence */ 28fbda0fcf2f9e82c82bcaac138f44d4e5144f6e0dpbos@webrtc.org int16_t dim1, /* (i) dimension first seq1 */ 29fbda0fcf2f9e82c82bcaac138f44d4e5144f6e0dpbos@webrtc.org const int16_t *seq2, /* (i) second sequence */ 30fbda0fcf2f9e82c82bcaac138f44d4e5144f6e0dpbos@webrtc.org int16_t dim2 /* (i) dimension seq2 */ 31b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org ){ 32fbda0fcf2f9e82c82bcaac138f44d4e5144f6e0dpbos@webrtc.org int16_t max, scale, loops; 33b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 34b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org /* Calculate correlation between the two sequences. Scale the 35b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org result of the multiplcication to maximum 26 bits in order 36b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org to avoid overflow */ 37b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org max=WebRtcSpl_MaxAbsValueW16(seq1, dim1); 38b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org scale=WebRtcSpl_GetSizeInBits(max); 39b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 40fbda0fcf2f9e82c82bcaac138f44d4e5144f6e0dpbos@webrtc.org scale = (int16_t)(WEBRTC_SPL_MUL_16_16(2,scale)-26); 41b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org if (scale<0) { 42b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org scale=0; 43b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org } 44b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 45b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org loops=dim1-dim2+1; 46b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 47b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org /* Calculate the cross correlations */ 48fbda0fcf2f9e82c82bcaac138f44d4e5144f6e0dpbos@webrtc.org WebRtcSpl_CrossCorrelation(corr, (int16_t*)seq2, seq1, dim2, loops, scale, 1); 49b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 50b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org return; 51b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org} 52