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_LsfCheck.c 16b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 17b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org******************************************************************/ 18b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 19b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org#include "defines.h" 20b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org#include "constants.h" 21b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 22b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org/*----------------------------------------------------------------* 23b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org * check for stability of lsf coefficients 24b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org *---------------------------------------------------------------*/ 25b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 26b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.orgint WebRtcIlbcfix_LsfCheck( 27fbda0fcf2f9e82c82bcaac138f44d4e5144f6e0dpbos@webrtc.org int16_t *lsf, /* LSF parameters */ 28b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org int dim, /* dimension of LSF */ 29b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org int NoAn) /* No of analysis per frame */ 30b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org{ 31b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org int k,n,m, Nit=2, change=0,pos; 32fbda0fcf2f9e82c82bcaac138f44d4e5144f6e0dpbos@webrtc.org const int16_t eps=319; /* 0.039 in Q13 (50 Hz)*/ 33fbda0fcf2f9e82c82bcaac138f44d4e5144f6e0dpbos@webrtc.org const int16_t eps2=160; /* eps/2.0 in Q13;*/ 34fbda0fcf2f9e82c82bcaac138f44d4e5144f6e0dpbos@webrtc.org const int16_t maxlsf=25723; /* 3.14; (4000 Hz)*/ 35fbda0fcf2f9e82c82bcaac138f44d4e5144f6e0dpbos@webrtc.org const int16_t minlsf=82; /* 0.01; (0 Hz)*/ 36b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 37b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org /* LSF separation check*/ 38b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org for (n=0;n<Nit;n++) { /* Run through a 2 times */ 39b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org for (m=0;m<NoAn;m++) { /* Number of analyses per frame */ 40b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org for (k=0;k<(dim-1);k++) { 41b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org pos=m*dim+k; 42b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 43b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org /* Seperate coefficients with a safety margin of 50 Hz */ 44b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org if ((lsf[pos+1]-lsf[pos])<eps) { 45b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 46b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org if (lsf[pos+1]<lsf[pos]) { 47b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org lsf[pos+1]= lsf[pos]+eps2; 48b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org lsf[pos]= lsf[pos+1]-eps2; 49b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org } else { 50b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org lsf[pos]-=eps2; 51b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org lsf[pos+1]+=eps2; 52b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org } 53b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org change=1; 54b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org } 55b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 56b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org /* Limit minimum and maximum LSF */ 57b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org if (lsf[pos]<minlsf) { 58b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org lsf[pos]=minlsf; 59b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org change=1; 60b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org } 61b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 62b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org if (lsf[pos]>maxlsf) { 63b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org lsf[pos]=maxlsf; 64b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org change=1; 65b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org } 66b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org } 67b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org } 68b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org } 69b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 70b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org return change; 71b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org} 72