1 /* 2 * Copyright (C) 2002-2003 Fhg Fokus 3 * 4 * This file is part of SEMS, a free SIP media server. 5 * 6 * SEMS is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation; either version 2 of the License, or 9 * (at your option) any later version. 10 * 11 * For a license to use the sems software under conditions 12 * other than those described here, or to purchase support for this 13 * software, please contact iptel.org by e-mail at the following addresses: 14 * info@iptel.org 15 * 16 * SEMS is distributed in the hope that it will be useful, 17 * but WITHOUT ANY WARRANTY; without even the implied warranty of 18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 19 * GNU General Public License for more details. 20 * 21 * You should have received a copy of the GNU General Public License 22 * along with this program; if not, write to the Free Software 23 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 24 */ 25 26 #ifndef _LowcFE_h_ 27 #define _LowcFE_h_ 28 29 #include "AmAudio.h" 30 31 typedef float Float; 32 33 #define PITCH_MIN ((unsigned int) (sample_rate / 200)) /* minimum allowed pitch, 200 Hz */ 34 #define PITCH_MAX ((unsigned int) (sample_rate / 66.6)) /* maximum allowed pitch, 66 Hz */ 35 #define PITCHDIFF (PITCH_MAX - PITCH_MIN) 36 #define POVERLAPMAX (PITCH_MAX >> 2) /* maximum pitch OLA window */ 37 #define HISTORYLEN (PITCH_MAX * 3 + POVERLAPMAX) /* history buff length*/ 38 #define NDEC 2 /* 2:1 decimation */ 39 #define CORRLEN 20 * sample_rate / 1000 /* 20 msec correlation length */ 40 #define CORRBUFLEN (CORRLEN + PITCH_MAX) /* correlation buffer length */ 41 #define CORRMINPOWER (((Float)250.) * (sample_rate / 8000)) /* minimum power */ 42 #define EOVERLAPINCR 32 /* end OLA increment per frame,4 ms */ 43 #define FRAMESZ (10 * sample_rate / 1000) /* 10 msec */ 44 #define ATTENFAC ((Float).2) /* attenu. factor per 10 ms frame */ 45 #define ATTENINCR (ATTENFAC/(Float)(FRAMESZ)) /* attenuation per sample */ 46 47 /** \brief LowcFE erased frame generator for fec (plc) */ 48 class LowcFE { 49 50 public: 51 LowcFE(unsigned int sample_rate); 52 ~LowcFE(); 53 void dofe(short *s); /* synthesize speech for erasure */ 54 void addtohistory(short *s); /* add a good frame to history buf */ 55 56 protected: 57 unsigned int sample_rate; 58 int erasecnt; /* consecutive erased frames */ 59 int poverlap; /* overlap based on pitch */ 60 int poffset; /* offset into pitch period */ 61 int pitch; /* pitch estimate */ 62 int pitchblen; /* current pitch buffer length */ 63 Float *pitchbufend; /* end of pitch buffer */ 64 Float *pitchbufstart; /* start of pitch buffer */ 65 Float *pitchbuf; /* buffer for cycles of speech */ 66 Float *lastq; /* saved last quarter wavelength */ 67 short *history; /* history buffer */ 68 69 void scalespeech(short *out); 70 void getfespeech(short *out, int sz); 71 void savespeech(short *s); 72 int findpitch(); 73 void overlapadd(Float *l, Float *r, Float *o, int cnt); 74 void overlapadd(short *l, short *r, short *o, int cnt); 75 void overlapaddatend(short *s, short *f, int cnt); 76 void convertsf(short *f, Float *t, int cnt); 77 void convertfs(Float *f, short *t, int cnt); 78 void copyf(Float *f, Float *t, int cnt); 79 void copys(short *f, short *t, int cnt); 80 void zeros(short *s, int cnt); 81 }; 82 83 84 #endif 85