mirror of
https://github.com/asterisk/asterisk.git
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Change the fsk filter used in CID and TDD decode to an integer based implementation
git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@78227 65c4cc65-6c06-0410-ace0-fbb531ad65f3
This commit is contained in:
Doug Bailey
324
main/fskmodem.c
324
main/fskmodem.c
@@ -46,17 +46,16 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
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#define STATE_SEARCH_STARTBIT3 2
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#define STATE_GET_BYTE 3
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static inline float get_sample(short **buffer, int *len)
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static inline int iget_sample(short **buffer, int *len)
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{
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float retval;
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retval = (float) **buffer / 256;
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int retval;
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retval = (int) **buffer;
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(*buffer)++;
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(*len)--;
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return retval;
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};
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#define GET_SAMPLE get_sample(&buffer, len)
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}
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#define IGET_SAMPLE iget_sample(&buffer, len)
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/*! \brief Coefficients for input filters
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* Coefficients table, generated by program "mkfilter"
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* mkfilter is part of the zapatatelephony.org distribution
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@@ -64,31 +63,20 @@ static inline float get_sample(short **buffer, int *len)
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* IDX_COEF = 0 => 1/GAIN
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* IDX_COEF = 1-6 => Coefficientes y[n]
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*/
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static double coef_in[NF][NBW][8] = {
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{
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{ 1.8229206611e-04,-7.8997325866e-01,2.2401819940e+00,-4.6751353581e+00,5.5080745712e+00,-5.0571565772e+00,2.6215820004e+00,0.0000000000e+00, },
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{ 9.8532175289e-02,-5.6297236492e-02,3.3146713415e-01,-9.2239200436e-01,1.4844365184e+00,-2.0183258642e+00,2.0074154497e+00,0.0000000000e+00, },
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},
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{
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{ 1.8229206610e-04,-7.8997325866e-01,7.7191410839e-01,-2.8075643964e+00,1.6948618347e+00,-3.0367273700e+00,9.0333559408e-01,0.0000000000e+00, } ,
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{ 9.8531161839e-02,-5.6297236492e-02,1.1421579050e-01,-4.8122536483e-01,4.0121072432e-01,-7.4834487567e-01,6.9170822332e-01,0.0000000000e+00, },
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},
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{
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{ 1.8229206611e-04,-7.8997325866e-01,2.9003821430e+00,-6.1082779024e+00,7.7169345751e+00,-6.6075999680e+00,3.3941838836e+00,0.0000000000e+00, },
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{ 9.8539686961e-02,-5.6297236492e-02,4.2915323820e-01,-1.2609358633e+00,2.2399213250e+00,-2.9928879142e+00,2.5990173742e+00,0.0000000000e+00, },
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},
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{
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{ 1.8229206610e-04,-7.8997325866e-01,-7.7191410839e-01,-2.8075643964e+00,-1.6948618347e+00,-3.0367273700e+00,-9.0333559408e-01,0.0000000000e+00, },
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{ 9.8531161839e-02,-5.6297236492e-02,-1.1421579050e-01,-4.8122536483e-01,-4.0121072432e-01,-7.4834487567e-01,-6.9170822332e-01,0.0000000000e+00, },
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},
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{
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{ 1.8229206611e-04,-7.8997325866e-01,2.5782298908e+00,-5.3629717478e+00,6.5890882172e+00,-5.8012914776e+00,3.0171839130e+00,0.0000000000e+00, },
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{ 9.8534230718e-02,-5.6297236492e-02,3.8148618075e-01,-1.0848760410e+00,1.8441165168e+00,-2.4860666655e+00,2.3103384142e+00,0.0000000000e+00, },
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},
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{
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{ 1.8229206610e-04,-7.8997325866e-01,-3.8715051001e-01,-2.6192408538e+00,-8.3977994034e-01,-2.8329897913e+00,-4.5306444352e-01,0.0000000000e+00, },
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{ 9.8531160936e-02,-5.6297236492e-02,-5.7284484199e-02,-4.3673866734e-01,-1.9564766257e-01,-6.2028156584e-01,-3.4692356122e-01,0.0000000000e+00, },
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},
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static double coef_in[NF][NBW][8]={
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{ { 1.8229206611e-04,-7.8997325866e-01,2.2401819940e+00,-4.6751353581e+00,5.5080745712e+00,-5.0571565772e+00,2.6215820004e+00,0.0000000000e+00,
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}, { 9.8532175289e-02,-5.6297236492e-02,3.3146713415e-01,-9.2239200436e-01,1.4844365184e+00,-2.0183258642e+00,2.0074154497e+00,0.0000000000e+00,
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}, }, { { 1.8229206610e-04,-7.8997325866e-01,7.7191410839e-01,-2.8075643964e+00,1.6948618347e+00,-3.0367273700e+00,9.0333559408e-01,0.0000000000e+00,
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}, { 9.8531161839e-02,-5.6297236492e-02,1.1421579050e-01,-4.8122536483e-01,4.0121072432e-01,-7.4834487567e-01,6.9170822332e-01,0.0000000000e+00,
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}, }, { { 1.8229206611e-04,-7.8997325866e-01,2.9003821430e+00,-6.1082779024e+00,7.7169345751e+00,-6.6075999680e+00,3.3941838836e+00,0.0000000000e+00,
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}, { 9.8539686961e-02,-5.6297236492e-02,4.2915323820e-01,-1.2609358633e+00,2.2399213250e+00,-2.9928879142e+00,2.5990173742e+00,0.0000000000e+00,
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}, }, { { 1.8229206610e-04,-7.8997325866e-01,-7.7191410839e-01,-2.8075643964e+00,-1.6948618347e+00,-3.0367273700e+00,-9.0333559408e-01,0.0000000000e+00,
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}, { 9.8531161839e-02,-5.6297236492e-02,-1.1421579050e-01,-4.8122536483e-01,-4.0121072432e-01,-7.4834487567e-01,-6.9170822332e-01,0.0000000000e+00,
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}, }, { { 1.8229206611e-04,-7.8997325866e-01,2.5782298908e+00,-5.3629717478e+00,6.5890882172e+00,-5.8012914776e+00,3.0171839130e+00,0.0000000000e+00,
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}, { 9.8534230718e-02,-5.6297236492e-02,3.8148618075e-01,-1.0848760410e+00,1.8441165168e+00,-2.4860666655e+00,2.3103384142e+00,0.0000000000e+00,
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}, }, { { 1.8229206610e-04,-7.8997325866e-01,-3.8715051001e-01,-2.6192408538e+00,-8.3977994034e-01,-2.8329897913e+00,-4.5306444352e-01,0.0000000000e+00,
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}, { 9.8531160936e-02,-5.6297236492e-02,-5.7284484199e-02,-4.3673866734e-01,-1.9564766257e-01,-6.2028156584e-01,-3.4692356122e-01,0.0000000000e+00,
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}, },
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};
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/*! \brief Coefficients for output filter
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@@ -96,134 +84,144 @@ static double coef_in[NF][NBW][8] = {
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* Format: coef[IDX_BW][IDX_COEF]
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* IDX_COEF = 0 => 1/GAIN
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* IDX_COEF = 1-6 => Coefficientes y[n]
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*/
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static double coef_out[NBW][8] = {
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{ 1.3868644653e-08,-6.3283665042e-01,4.0895057217e+00,-1.1020074592e+01,1.5850766191e+01,-1.2835109292e+01,5.5477477340e+00,0.0000000000e+00, },
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{ 3.1262119724e-03,-7.8390522307e-03,8.5209627801e-02,-4.0804129163e-01,1.1157139955e+00,-1.8767603680e+00,1.8916395224e+00,0.0000000000e+00, },
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*/
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static double coef_out[NBW][8]={
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{ 1.3868644653e-08,-6.3283665042e-01,4.0895057217e+00,-1.1020074592e+01,1.5850766191e+01,-1.2835109292e+01,5.5477477340e+00,0.0000000000e+00,
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}, { 3.1262119724e-03,-7.8390522307e-03,8.5209627801e-02,-4.0804129163e-01,1.1157139955e+00,-1.8767603680e+00,1.8916395224e+00,0.0000000000e+00
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},
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};
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/*! Band-pass filter for MARK frequency */
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static inline float filterM(fsk_data *fskd,float in)
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/*! Integer Pass Band demodulator filter */
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static inline int ibpdfilter(struct filter_struct * fs, int in)
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{
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int i, j;
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double s;
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double *pc;
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int i,j;
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int s;
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int64_t s_interim;
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pc = &coef_in[fskd->f_mark_idx][fskd->bw][0];
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fskd->fmxv[(fskd->fmp+6)&7] = in*(*pc++);
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/* integer filter */
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s = in * fs->icoefs[0];
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fs->ixv[(fs->ip+6)&7] = s;
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s = (fskd->fmxv[(fskd->fmp + 6) & 7] - fskd->fmxv[fskd->fmp]) + 3 * (fskd->fmxv[(fskd->fmp + 2) & 7] - fskd->fmxv[(fskd->fmp + 4) & 7]);
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for (i = 0, j = fskd->fmp; i < 6; i++, j++)
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s += fskd->fmyv[j&7]*(*pc++);
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fskd->fmyv[j&7] = s;
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fskd->fmp++;
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fskd->fmp &= 7;
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s= (fs->ixv[fs->ip] + fs->ixv[(fs->ip+6)&7]) +
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6 * (fs->ixv[(fs->ip+1)&7] + fs->ixv[(fs->ip+5)&7]) +
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15 * (fs->ixv[(fs->ip+2)&7] + fs->ixv[(fs->ip+4)&7]) +
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20 * fs->ixv[(fs->ip+3)&7];
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for (i=1,j=fs->ip; i < 7; i++,j++) {
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/* Promote operation to 64 bit to prevent overflow that occurred in 32 bit) */
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s_interim = (int64_t)(fs->iyv[j & 7]) *
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(int64_t)(fs->icoefs[i]) /
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(int64_t)(1024);
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s += (int)s_interim;
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}
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fs->iyv[ j & 7] = s;
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fs->ip++;
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fs->ip &= 7;
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return s;
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}
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/*! Band-pass filter for SPACE frequency */
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static inline float filterS(fsk_data *fskd,float in)
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/*! Integer Band Pass filter */
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static inline int ibpfilter(struct filter_struct * fs, int in)
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{
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int i, j;
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double s;
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double *pc;
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int i,j;
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int s;
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int64_t s_interim;
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pc = &coef_in[fskd->f_space_idx][fskd->bw][0];
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fskd->fsxv[(fskd->fsp+6)&7] = in*(*pc++);
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/* integer filter */
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s = in * fs->icoefs[0] / 256;
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fs->ixv[(fs->ip+6) & 7] = s;
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s = (fskd->fsxv[(fskd->fsp + 6) & 7] - fskd->fsxv[fskd->fsp]) + 3 * (fskd->fsxv[(fskd->fsp + 2) & 7] - fskd->fsxv[(fskd->fsp + 4) & 7]);
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for (i = 0, j = fskd->fsp; i < 6; i++, j++)
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s += fskd->fsyv[j&7]*(*pc++);
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fskd->fsyv[j&7] = s;
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fskd->fsp++;
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fskd->fsp &= 7;
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s = (fs->ixv[(fs->ip+6) & 7] - fs->ixv[fs->ip])
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+ 3 * (fs->ixv[(fs->ip+2) & 7] - fs->ixv[(fs->ip+4) & 7]);
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for (i=1,j=fs->ip; i < 7; i++,j++) {
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s_interim = (int64_t)(fs->iyv[j&7]) *
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(int64_t)(fs->icoefs[i]) /
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(int64_t)(256);
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s+= (int)s_interim;
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}
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fs->iyv[j&7]=s;
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fs->ip++; fs->ip &= 7;
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return s;
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}
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/*! Low-pass filter for demodulated data */
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static inline float filterL(fsk_data *fskd,float in)
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static inline int idemodulator(fsk_data *fskd, int *retval, int x)
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{
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int i, j;
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double s;
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double *pc;
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int is, im, id;
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int ilin2;
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is = ibpfilter(&fskd->space_filter, x);
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im = ibpfilter(&fskd->mark_filter, x);
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pc = &coef_out[fskd->bw][0];
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fskd->flxv[(fskd->flp + 6) & 7] = in * (*pc++);
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ilin2 = ((im * im) - (is * is))/(256 * 256);
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s = (fskd->flxv[fskd->flp] + fskd->flxv[(fskd->flp+6)&7]) +
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6 * (fskd->flxv[(fskd->flp+1)&7] + fskd->flxv[(fskd->flp+5)&7]) +
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15 * (fskd->flxv[(fskd->flp+2)&7] + fskd->flxv[(fskd->flp+4)&7]) +
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20 * fskd->flxv[(fskd->flp+3)&7];
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id = ibpdfilter(&fskd->demod_filter, ilin2);
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for (i = 0,j = fskd->flp;i<6;i++,j++)
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s += fskd->flyv[j&7]*(*pc++);
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fskd->flyv[j&7] = s;
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fskd->flp++;
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fskd->flp &= 7;
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return s;
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}
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static inline int demodulator(fsk_data *fskd, float *retval, float x)
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{
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float xS,xM;
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fskd->cola_in[fskd->pcola] = x;
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xS = filterS(fskd,x);
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xM = filterM(fskd,x);
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fskd->cola_filter[fskd->pcola] = xM-xS;
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x = filterL(fskd,xM*xM - xS*xS);
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fskd->cola_demod[fskd->pcola++] = x;
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fskd->pcola &= (NCOLA-1);
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*retval = x;
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*retval = id;
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return 0;
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}
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static int get_bit_raw(fsk_data *fskd, short *buffer, int *len)
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{
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/* This function implements a DPLL to synchronize with the bits */
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float x,spb,spb2,ds;
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int f;
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spb = fskd->spb;
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if (fskd->spb == 7)
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spb = 8000.0 / 1200.0;
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ds = spb/32.;
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spb2 = spb/2.;
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for (f = 0;;) {
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if (demodulator(fskd, &x, GET_SAMPLE))
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return -1;
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if ((x * fskd->x0) < 0) { /* Transition */
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int ix;
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/* PLL coeffs are set up in callerid_new */
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for (f = 0;;){
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if (idemodulator(fskd, &ix, IGET_SAMPLE)) return(-1);
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if ((ix * fskd->xi0)<0) { /* Transicion */
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if (!f) {
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if (fskd->cont<(spb2))
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fskd->cont += ds;
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else
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fskd->cont -= ds;
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f = 1;
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if (fskd->icont<(fskd->pllispb2))
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fskd->icont+=fskd->pllids;
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else
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fskd->icont-=fskd->pllids;
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f=1;
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}
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}
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fskd->x0 = x;
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fskd->cont += 1.;
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if (fskd->cont > spb) {
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fskd->cont -= spb;
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fskd->xi0=ix;
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fskd->icont+=32;
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if (fskd->icont>fskd->pllispb) {
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fskd->icont-=fskd->pllispb;
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break;
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}
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}
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f = (x > 0) ? 0x80 : 0;
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f=(ix>0)?0x80:0;
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return f;
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}
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int fskmodem_init(fsk_data *fskd)
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{
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int i;
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fskd->space_filter.ip = 0;
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fskd->mark_filter.ip = 0;
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fskd->demod_filter.ip = 0;
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for ( i = 0 ; i < 7 ; i++ ) {
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fskd->space_filter.icoefs[i] =
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coef_in[fskd->f_space_idx][fskd->bw][i] * 256;
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fskd->space_filter.ixv[i] = 0;;
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fskd->space_filter.iyv[i] = 0;;
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fskd->mark_filter.icoefs[i] =
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coef_in[fskd->f_mark_idx][fskd->bw][i] * 256;
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fskd->mark_filter.ixv[i] = 0;;
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fskd->mark_filter.iyv[i] = 0;;
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fskd->demod_filter.icoefs[i] =
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coef_out[fskd->bw][i] * 1024;
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fskd->demod_filter.ixv[i] = 0;;
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fskd->demod_filter.iyv[i] = 0;;
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}
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return 0;
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}
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int fsk_serial(fsk_data *fskd, short *buffer, int *len, int *outbyte)
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{
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int a;
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int i,j,n1,r;
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int samples = 0;
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int samples=0;
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int olen;
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int beginlen=*len;
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int beginlenx;
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@@ -243,56 +241,58 @@ int fsk_serial(fsk_data *fskd, short *buffer, int *len, int *outbyte)
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to look for the beginning of the start bit. Unfortunately, since TTY/TDD's
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just start sending a start bit with nothing preceding it at the beginning
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of a transmission (what a LOSING design), we cant do it this elegantly */
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/*
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if (demodulator(zap,&x1)) return(-1);
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for (;;) {
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if (demodulator(zap,&x2)) return(-1);
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if (x1>0 && x2<0) break;
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x1 = x2;
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}
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/* 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;
|
||||
|
||||
Reference in New Issue
Block a user