diff options
author | dbailey <dbailey@f38db490-d61c-443f-a65b-d21fe96a405b> | 2007-08-06 19:52:40 +0000 |
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committer | dbailey <dbailey@f38db490-d61c-443f-a65b-d21fe96a405b> | 2007-08-06 19:52:40 +0000 |
commit | aea3c1d33fdb0f9909a1cd471bffc68344bd70e9 (patch) | |
tree | e0afd225c0798db143d3f9595132802a471ea894 /main/fskmodem.c | |
parent | 59d1fbc49cc2b332bb825ea28da88dca25848a99 (diff) |
Change the fsk filter used in CID and TDD decode to an integer based implementation
git-svn-id: http://svn.digium.com/svn/asterisk/trunk@78227 f38db490-d61c-443f-a65b-d21fe96a405b
Diffstat (limited to 'main/fskmodem.c')
-rw-r--r-- | main/fskmodem.c | 322 |
1 files changed, 162 insertions, 160 deletions
diff --git a/main/fskmodem.c b/main/fskmodem.c index f77300979..bfadca608 100644 --- a/main/fskmodem.c +++ b/main/fskmodem.c @@ -46,17 +46,16 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revision$") #define STATE_SEARCH_STARTBIT3 2 #define STATE_GET_BYTE 3 -static inline float get_sample(short **buffer, int *len) +static inline int iget_sample(short **buffer, int *len) { - float retval; - retval = (float) **buffer / 256; + int retval; + retval = (int) **buffer; (*buffer)++; (*len)--; return retval; -}; - -#define GET_SAMPLE get_sample(&buffer, len) +} +#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 @@ -64,31 +63,20 @@ static inline float get_sample(short **buffer, int *len) * 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, }, - }, +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 @@ -96,134 +84,144 @@ static double coef_in[NF][NBW][8] = { * 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, }, +*/ +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 + }, }; - -/*! Band-pass filter for MARK frequency */ -static inline float filterM(fsk_data *fskd,float in) +/*! Integer Pass Band demodulator filter */ +static inline int ibpdfilter(struct filter_struct * fs, int in) { - int i, j; - double s; - double *pc; - - pc = &coef_in[fskd->f_mark_idx][fskd->bw][0]; - fskd->fmxv[(fskd->fmp+6)&7] = in*(*pc++); + int i,j; + int s; + int64_t s_interim; - s = (fskd->fmxv[(fskd->fmp + 6) & 7] - fskd->fmxv[fskd->fmp]) + 3 * (fskd->fmxv[(fskd->fmp + 2) & 7] - fskd->fmxv[(fskd->fmp + 4) & 7]); - for (i = 0, j = fskd->fmp; i < 6; i++, j++) - s += fskd->fmyv[j&7]*(*pc++); - fskd->fmyv[j&7] = s; - fskd->fmp++; - fskd->fmp &= 7; - return s; -} - -/*! Band-pass filter for SPACE frequency */ -static inline float filterS(fsk_data *fskd,float in) -{ - int i, j; - double s; - double *pc; + /* integer filter */ + s = in * fs->icoefs[0]; + fs->ixv[(fs->ip+6)&7] = s; - pc = &coef_in[fskd->f_space_idx][fskd->bw][0]; - fskd->fsxv[(fskd->fsp+6)&7] = in*(*pc++); + 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]; - s = (fskd->fsxv[(fskd->fsp + 6) & 7] - fskd->fsxv[fskd->fsp]) + 3 * (fskd->fsxv[(fskd->fsp + 2) & 7] - fskd->fsxv[(fskd->fsp + 4) & 7]); - for (i = 0, j = fskd->fsp; i < 6; i++, j++) - s += fskd->fsyv[j&7]*(*pc++); - fskd->fsyv[j&7] = s; - fskd->fsp++; - fskd->fsp &= 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; } -/*! Low-pass filter for demodulated data */ -static inline float filterL(fsk_data *fskd,float in) +/*! Integer Band Pass filter */ +static inline int ibpfilter(struct filter_struct * fs, int in) { - int i, j; - double s; - double *pc; + int i,j; + int s; + int64_t s_interim; - pc = &coef_out[fskd->bw][0]; - fskd->flxv[(fskd->flp + 6) & 7] = in * (*pc++); + /* integer filter */ + s = in * fs->icoefs[0] / 256; + fs->ixv[(fs->ip+6) & 7] = s; - s = (fskd->flxv[fskd->flp] + fskd->flxv[(fskd->flp+6)&7]) + - 6 * (fskd->flxv[(fskd->flp+1)&7] + fskd->flxv[(fskd->flp+5)&7]) + - 15 * (fskd->flxv[(fskd->flp+2)&7] + fskd->flxv[(fskd->flp+4)&7]) + - 20 * fskd->flxv[(fskd->flp+3)&7]; + 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 = 0,j = fskd->flp;i<6;i++,j++) - s += fskd->flyv[j&7]*(*pc++); - fskd->flyv[j&7] = s; - fskd->flp++; - fskd->flp &= 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 demodulator(fsk_data *fskd, float *retval, float x) +static inline int idemodulator(fsk_data *fskd, int *retval, int x) { - float xS,xM; - - fskd->cola_in[fskd->pcola] = x; + int is, im, id; + int ilin2; + + is = ibpfilter(&fskd->space_filter, x); + im = ibpfilter(&fskd->mark_filter, x); - xS = filterS(fskd,x); - xM = filterM(fskd,x); - - fskd->cola_filter[fskd->pcola] = xM-xS; - - x = filterL(fskd,xM*xM - xS*xS); + ilin2 = ((im * im) - (is * is))/(256 * 256); - fskd->cola_demod[fskd->pcola++] = x; - fskd->pcola &= (NCOLA-1); - - *retval = x; + 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 */ - float x,spb,spb2,ds; int f; - spb = fskd->spb; - if (fskd->spb == 7) - spb = 8000.0 / 1200.0; - ds = spb/32.; - spb2 = spb/2.; - - for (f = 0;;) { - if (demodulator(fskd, &x, GET_SAMPLE)) - return -1; - if ((x * fskd->x0) < 0) { /* Transition */ + 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->cont<(spb2)) - fskd->cont += ds; - else - fskd->cont -= ds; - f = 1; + if (fskd->icont<(fskd->pllispb2)) + fskd->icont+=fskd->pllids; + else + fskd->icont-=fskd->pllids; + f=1; } } - fskd->x0 = x; - fskd->cont += 1.; - if (fskd->cont > spb) { - fskd->cont -= spb; + fskd->xi0=ix; + fskd->icont+=32; + if (fskd->icont>fskd->pllispb) { + fskd->icont-=fskd->pllispb; break; } } - f = (x > 0) ? 0x80 : 0; + 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 samples=0; int olen; int beginlen=*len; int beginlenx; @@ -243,56 +241,58 @@ int fsk_serial(fsk_data *fskd, short *buffer, int *len, int *outbyte) 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 */ - /* - if (demodulator(zap,&x1)) return(-1); - for (;;) { - if (demodulator(zap,&x2)) return(-1); - if (x1>0 && x2<0) break; - x1 = x2; - } + /* 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 (demodulator(fskd, &fskd->x1, GET_SAMPLE)) + if (idemodulator(fskd, &fskd->xi1, IGET_SAMPLE)) return -1; samples++; - for (;;) { + for(;;) { search_startbit2: if (*len <= 0) { - fskd->state = STATE_SEARCH_STARTBIT2; + fskd->state = STATE_SEARCH_STARTBIT2; return 0; } samples++; - if (demodulator(fskd, &fskd->x2, GET_SAMPLE)) - return(-1); + if (idemodulator(fskd,&fskd->xi2,IGET_SAMPLE)) + return -1; #if 0 - printf("x2 = %5.5f ", fskd->x2); + printf("xi2 = %d ", fskd->xi2); #endif - if (fskd->x2 < -0.5) + if (fskd->xi2 < 512) break; } search_startbit3: /* We await for 0.5 bits before using DPLL */ - i = fskd->spb/2; + i=fskd->ispb/2; if (*len < i) { fskd->state = STATE_SEARCH_STARTBIT3; return 0; } for (; i>0; i--) { - if (demodulator(fskd, &fskd->x1, GET_SAMPLE)) + if (idemodulator(fskd, &fskd->xi1, IGET_SAMPLE)) return(-1); #if 0 - printf("x1 = %5.5f ", fskd->x1); + printf("xi1 = %d ", fskd->xi1); #endif - samples++; + samples++; } - /* x1 must be negative (start bit confirmation) */ + /* x1 must be negative (start bit confirmation) */ - } while (fskd->x1 > 0); + } while (fskd->xi1>0); fskd->state = STATE_GET_BYTE; getbyte: @@ -306,18 +306,19 @@ getbyte: 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) + if (i == -1) + return -1; + if (i) n1++; - a >>= 1; - a |= i; + a >>= 1; + a |= i; } j = 8-fskd->nbit; a >>= j; @@ -327,33 +328,34 @@ getbyte: olen = *len; i = get_bit_raw(fskd, buffer, len); buffer += (olen - *len); - if (i == -1) - return(-1); - if (i) + 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 */ + 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->nstop;j;j--) { + for (j=fskd->instop; j; j--) { r = get_bit_raw(fskd, buffer, len); - if (r == -1) - return(-1); - if (!r) + if (r == -1) + return -1; + if (!r) a |= 0x200; } - /* And finally we return */ - /* Bit 8 : Parity error */ - /* Bit 9 : Framming error*/ - + /* And finally we return + * Bit 8 : Parity error + * Bit 9 : Framming error + */ + *outbyte = a; fskd->state = STATE_SEARCH_STARTBIT; return 1; |