From f8247040e6231c4b3b5099ea3a526348b7941566 Mon Sep 17 00:00:00 2001 From: russell Date: Sat, 19 Jan 2008 00:19:29 +0000 Subject: Creating tag for the release of asterisk-1.6.0-beta1 git-svn-id: http://svn.digium.com/svn/asterisk/tags/1.6.0-beta1@99163 f38db490-d61c-443f-a65b-d21fe96a405b --- trunk/main/fskmodem.c | 360 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 360 insertions(+) create mode 100644 trunk/main/fskmodem.c (limited to 'trunk/main/fskmodem.c') diff --git a/trunk/main/fskmodem.c b/trunk/main/fskmodem.c new file mode 100644 index 000000000..e59024834 --- /dev/null +++ b/trunk/main/fskmodem.c @@ -0,0 +1,360 @@ +/* + * Asterisk -- An open source telephony toolkit. + * + * Copyright (C) 1999 - 2005, Digium, Inc. + * + * Mark Spencer + * + * Includes code and algorithms from the Zapata library. + * + * See http://www.asterisk.org for more information about + * the Asterisk project. Please do not directly contact + * any of the maintainers of this project for assistance; + * the project provides a web site, mailing lists and IRC + * channels for your use. + * + * This program is free software, distributed under the terms of + * the GNU General Public License Version 2. See the LICENSE file + * at the top of the source tree. + */ + +/*! \file + * + * \brief FSK Modulator/Demodulator + * + * \author Mark Spencer + * + * \arg Includes code and algorithms from the Zapata library. + * + */ + +#include "asterisk.h" + +ASTERISK_FILE_VERSION(__FILE__, "$Revision$") + +#include "asterisk/fskmodem.h" + +#define NBW 2 +#define BWLIST {75,800} +#define NF 6 +#define FLIST {1400,1800,1200,2200,1300,2100} + +#define STATE_SEARCH_STARTBIT 0 +#define STATE_SEARCH_STARTBIT2 1 +#define STATE_SEARCH_STARTBIT3 2 +#define STATE_GET_BYTE 3 + +static inline int iget_sample(short **buffer, int *len) +{ + int retval; + retval = (int) **buffer; + (*buffer)++; + (*len)--; + return retval; +} + +#define IGET_SAMPLE iget_sample(&buffer, len) +/*! \brief Coefficients for input filters + * Coefficients table, generated by program "mkfilter" + * mkfilter is part of the zapatatelephony.org distribution + * Format: coef[IDX_FREC][IDX_BW][IDX_COEF] + * IDX_COEF = 0 => 1/GAIN + * IDX_COEF = 1-6 => Coefficientes y[n] +*/ +static double coef_in[NF][NBW][8]={ + { { 1.8229206611e-04,-7.8997325866e-01,2.2401819940e+00,-4.6751353581e+00,5.5080745712e+00,-5.0571565772e+00,2.6215820004e+00,0.0000000000e+00, + }, { 9.8532175289e-02,-5.6297236492e-02,3.3146713415e-01,-9.2239200436e-01,1.4844365184e+00,-2.0183258642e+00,2.0074154497e+00,0.0000000000e+00, + }, }, { { 1.8229206610e-04,-7.8997325866e-01,7.7191410839e-01,-2.8075643964e+00,1.6948618347e+00,-3.0367273700e+00,9.0333559408e-01,0.0000000000e+00, + }, { 9.8531161839e-02,-5.6297236492e-02,1.1421579050e-01,-4.8122536483e-01,4.0121072432e-01,-7.4834487567e-01,6.9170822332e-01,0.0000000000e+00, + }, }, { { 1.8229206611e-04,-7.8997325866e-01,2.9003821430e+00,-6.1082779024e+00,7.7169345751e+00,-6.6075999680e+00,3.3941838836e+00,0.0000000000e+00, + }, { 9.8539686961e-02,-5.6297236492e-02,4.2915323820e-01,-1.2609358633e+00,2.2399213250e+00,-2.9928879142e+00,2.5990173742e+00,0.0000000000e+00, + }, }, { { 1.8229206610e-04,-7.8997325866e-01,-7.7191410839e-01,-2.8075643964e+00,-1.6948618347e+00,-3.0367273700e+00,-9.0333559408e-01,0.0000000000e+00, + }, { 9.8531161839e-02,-5.6297236492e-02,-1.1421579050e-01,-4.8122536483e-01,-4.0121072432e-01,-7.4834487567e-01,-6.9170822332e-01,0.0000000000e+00, + }, }, { { 1.8229206611e-04,-7.8997325866e-01,2.5782298908e+00,-5.3629717478e+00,6.5890882172e+00,-5.8012914776e+00,3.0171839130e+00,0.0000000000e+00, + }, { 9.8534230718e-02,-5.6297236492e-02,3.8148618075e-01,-1.0848760410e+00,1.8441165168e+00,-2.4860666655e+00,2.3103384142e+00,0.0000000000e+00, + }, }, { { 1.8229206610e-04,-7.8997325866e-01,-3.8715051001e-01,-2.6192408538e+00,-8.3977994034e-01,-2.8329897913e+00,-4.5306444352e-01,0.0000000000e+00, + }, { 9.8531160936e-02,-5.6297236492e-02,-5.7284484199e-02,-4.3673866734e-01,-1.9564766257e-01,-6.2028156584e-01,-3.4692356122e-01,0.0000000000e+00, + }, }, +}; + +/*! \brief Coefficients for output filter + * Coefficients table, generated by program "mkfilter" + * Format: coef[IDX_BW][IDX_COEF] + * IDX_COEF = 0 => 1/GAIN + * IDX_COEF = 1-6 => Coefficientes y[n] +*/ +static double coef_out[NBW][8]={ + { 1.3868644653e-08,-6.3283665042e-01,4.0895057217e+00,-1.1020074592e+01,1.5850766191e+01,-1.2835109292e+01,5.5477477340e+00,0.0000000000e+00, + }, { 3.1262119724e-03,-7.8390522307e-03,8.5209627801e-02,-4.0804129163e-01,1.1157139955e+00,-1.8767603680e+00,1.8916395224e+00,0.0000000000e+00 + }, +}; + +/*! Integer Pass Band demodulator filter */ +static inline int ibpdfilter(struct filter_struct * fs, int in) +{ + int i,j; + int s; + int64_t s_interim; + + /* integer filter */ + s = in * fs->icoefs[0]; + fs->ixv[(fs->ip+6)&7] = s; + + s= (fs->ixv[fs->ip] + fs->ixv[(fs->ip+6)&7]) + + 6 * (fs->ixv[(fs->ip+1)&7] + fs->ixv[(fs->ip+5)&7]) + + 15 * (fs->ixv[(fs->ip+2)&7] + fs->ixv[(fs->ip+4)&7]) + + 20 * fs->ixv[(fs->ip+3)&7]; + + for (i=1, j=fs->ip; i < 7; i++,j++) { + /* Promote operation to 64 bit to prevent overflow that occurred in 32 bit) */ + s_interim = (int64_t)(fs->iyv[j & 7]) * + (int64_t)(fs->icoefs[i]) / + (int64_t)(1024); + s += (int) s_interim; + } + fs->iyv[ j & 7] = s; + fs->ip++; + fs->ip &= 7; + return s; +} + +/*! Integer Band Pass filter */ +static inline int ibpfilter(struct filter_struct * fs, int in) +{ + int i, j; + int s; + int64_t s_interim; + + /* integer filter */ + s = in * fs->icoefs[0] / 256; + fs->ixv[(fs->ip+6) & 7] = s; + + s = (fs->ixv[(fs->ip+6) & 7] - fs->ixv[fs->ip]) + + 3 * (fs->ixv[(fs->ip+2) & 7] - fs->ixv[(fs->ip+4) & 7]); + + for (i=1,j=fs->ip; i < 7; i++,j++) { + s_interim = (int64_t)(fs->iyv[j&7]) * + (int64_t)(fs->icoefs[i]) / + (int64_t)(256); + s+= (int) s_interim; + } + fs->iyv[j&7]=s; + fs->ip++; fs->ip &= 7; + return s; +} + +static inline int idemodulator(fsk_data *fskd, int *retval, int x) +{ + int is, im, id; + int ilin2; + + is = ibpfilter(&fskd->space_filter, x); + im = ibpfilter(&fskd->mark_filter, x); + + ilin2 = ((im * im) - (is * is))/(256 * 256); + + id = ibpdfilter(&fskd->demod_filter, ilin2); + + *retval = id; + return 0; +} + +static int get_bit_raw(fsk_data *fskd, short *buffer, int *len) +{ + /* This function implements a DPLL to synchronize with the bits */ + int f; + + int ix; + /* PLL coeffs are set up in callerid_new */ + for (f = 0;;){ + if (idemodulator(fskd, &ix, IGET_SAMPLE)) return(-1); + if ((ix * fskd->xi0)<0) { /* Transicion */ + if (!f) { + if (fskd->icont<(fskd->pllispb2)) + fskd->icont+=fskd->pllids; + else + fskd->icont-=fskd->pllids; + f = 1; + } + } + fskd->xi0=ix; + fskd->icont+=32; + if (fskd->icont>fskd->pllispb) { + fskd->icont-=fskd->pllispb; + break; + } + } + f=(ix>0)?0x80:0; + return f; +} + +int fskmodem_init(fsk_data *fskd) +{ + int i; + + fskd->space_filter.ip = 0; + fskd->mark_filter.ip = 0; + fskd->demod_filter.ip = 0; + + for ( i = 0 ; i < 7 ; i++ ) { + fskd->space_filter.icoefs[i] = + coef_in[fskd->f_space_idx][fskd->bw][i] * 256; + fskd->space_filter.ixv[i] = 0;; + fskd->space_filter.iyv[i] = 0;; + + fskd->mark_filter.icoefs[i] = + coef_in[fskd->f_mark_idx][fskd->bw][i] * 256; + fskd->mark_filter.ixv[i] = 0;; + fskd->mark_filter.iyv[i] = 0;; + + fskd->demod_filter.icoefs[i] = + coef_out[fskd->bw][i] * 1024; + fskd->demod_filter.ixv[i] = 0;; + fskd->demod_filter.iyv[i] = 0;; + } + return 0; +} + +int fsk_serial(fsk_data *fskd, short *buffer, int *len, int *outbyte) +{ + int a; + int i, j, n1, r; + int samples = 0; + int olen; + int beginlen = *len; + int beginlenx; + + switch (fskd->state) { + /* Pick up where we left off */ + case STATE_SEARCH_STARTBIT2: + goto search_startbit2; + case STATE_SEARCH_STARTBIT3: + goto search_startbit3; + case STATE_GET_BYTE: + goto getbyte; + } + /* We await for start bit */ + do { + /* this was jesus's nice, reasonable, working (at least with RTTY) code + to look for the beginning of the start bit. Unfortunately, since TTY/TDD's + just start sending a start bit with nothing preceding it at the beginning + of a transmission (what a LOSING design), we cant do it this elegantly */ + /* NOT USED + if (demodulator(zap,&x1)) + return -1; + for(;;) { + if (demodulator(zap,&x2)) + return -1; + if (x1>0 && x2<0) break; + x1=x2; + } + */ + /* this is now the imprecise, losing, but functional code to detect the + beginning of a start bit in the TDD sceanario. It just looks for sufficient + level to maybe, perhaps, guess, maybe that its maybe the beginning of + a start bit, perhaps. This whole thing stinks! */ + beginlenx=beginlen; /* just to avoid unused war warnings */ + if (idemodulator(fskd, &fskd->xi1, IGET_SAMPLE)) + return -1; + samples++; + for(;;) { +search_startbit2: + if (*len <= 0) { + fskd->state = STATE_SEARCH_STARTBIT2; + return 0; + } + samples++; + if (idemodulator(fskd,&fskd->xi2,IGET_SAMPLE)) + return -1; +#if 0 + printf("xi2 = %d ", fskd->xi2); +#endif + if (fskd->xi2 < 512) + break; + } +search_startbit3: + /* We await for 0.5 bits before using DPLL */ + i=fskd->ispb/2; + if (*len < i) { + fskd->state = STATE_SEARCH_STARTBIT3; + return 0; + } + for (; i>0; i--) { + if (idemodulator(fskd, &fskd->xi1, IGET_SAMPLE)) + return(-1); +#if 0 + printf("xi1 = %d ", fskd->xi1); +#endif + samples++; + } + + /* x1 must be negative (start bit confirmation) */ + + } while (fskd->xi1>0); + fskd->state = STATE_GET_BYTE; + +getbyte: + + /* Need at least 80 samples (for 1200) or + 1320 (for 45.5) to be sure we'll have a byte */ + if (fskd->nbit < 8) { + if (*len < 1320) + return 0; + } else { + if (*len < 80) + return 0; + } + + /* Now we read the data bits */ + j = fskd->nbit; + for (a = n1 = 0; j; j--) { + olen = *len; + i = get_bit_raw(fskd, buffer, len); + buffer += (olen - *len); + if (i == -1) + return -1; + if (i) + n1++; + a >>= 1; + a |= i; + } + j = 8 - fskd->nbit; + a >>= j; + + /* We read parity bit (if exists) and check parity */ + if (fskd->parity) { + olen = *len; + i = get_bit_raw(fskd, buffer, len); + buffer += (olen - *len); + if (i == -1) + return -1; + if (i) + n1++; + if (fskd->parity == 1) { /* parity=1 (even) */ + if (n1 & 1) + a |= 0x100; /* error */ + } else { /* parity=2 (odd) */ + if (!(n1 & 1)) + a |= 0x100; /* error */ + } + } + + /* We read STOP bits. All of them must be 1 */ + + for (j = fskd->instop; j; j--) { + r = get_bit_raw(fskd, buffer, len); + if (r == -1) + return -1; + if (!r) + a |= 0x200; + } + + /* And finally we return + * Bit 8 : Parity error + * Bit 9 : Framming error + */ + + *outbyte = a; + fskd->state = STATE_SEARCH_STARTBIT; + return 1; +} -- cgit v1.2.3