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WSJT-X/lib/wsprd/wsprd.c
Bill Somerville ac3c7babf7 Correct Fortran - C interop in wsprd code 
git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@5571 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
2015-06-10 14:48:26 +00:00

935 lines
32 KiB
C
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/*
This file is part of program wsprd, a detector/demodulator/decoder
for the Weak Signal Propagation Reporter (WSPR) mode.
File name: wsprd.c
Copyright 2001-2015, Joe Taylor, K1JT
Much of the present code is based on work by Steven Franke, K9AN,
which in turn was based on earlier work by K1JT.
Copyright 2014-2015, Steven Franke, K9AN
License: GNU GPL v3
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <math.h>
#include <string.h>
#include <stdint.h>
#include <time.h>
#include <fftw3.h>
#include "fano.h"
#include "wsprd_utils.h"
#define max(x,y) ((x) > (y) ? (x) : (y))
// Possible PATIENCE options: FFTW_ESTIMATE, FFTW_ESTIMATE_PATIENT,
// FFTW_MEASURE, FFTW_PATIENT, FFTW_EXHAUSTIVE
#define PATIENCE FFTW_ESTIMATE
fftw_plan PLAN1,PLAN2,PLAN3;
unsigned char pr3[162]=
{1,1,0,0,0,0,0,0,1,0,0,0,1,1,1,0,0,0,1,0,
0,1,0,1,1,1,1,0,0,0,0,0,0,0,1,0,0,1,0,1,
0,0,0,0,0,0,1,0,1,1,0,0,1,1,0,1,0,0,0,1,
1,0,1,0,0,0,0,1,1,0,1,0,1,0,1,0,1,0,0,1,
0,0,1,0,1,1,0,0,0,1,1,0,1,0,1,0,0,0,1,0,
0,0,0,0,1,0,0,1,0,0,1,1,1,0,1,1,0,0,1,1,
0,1,0,0,0,1,1,1,0,0,0,0,0,1,0,1,0,0,1,1,
0,0,0,0,0,0,0,1,1,0,1,0,1,1,0,0,0,1,1,0,
0,0};
unsigned long nr;
//***************************************************************************
unsigned long readc2file(char *ptr_to_infile, double *idat, double *qdat,
double *freq, int *wspr_type)
{
float buffer[2*65536];
double dfreq;
int i,ntrmin;
char *c2file[15];
FILE* fp;
fp = fopen(ptr_to_infile,"rb");
if (fp == NULL) {
fprintf(stderr, "Cannot open data file '%s'\n", ptr_to_infile);
return 1;
}
unsigned long nread=fread(c2file,sizeof(char),14,fp);
nread=fread(&ntrmin,sizeof(int),1,fp);
nread=fread(&dfreq,sizeof(double),1,fp);
*freq=dfreq;
nread=fread(buffer,sizeof(float),2*45000,fp);
*wspr_type=ntrmin;
for(i=0; i<45000; i++) {
idat[i]=buffer[2*i];
qdat[i]=-buffer[2*i+1];
}
if( nread == 2*45000 ) {
return nread/2;
} else {
return 1;
}
}
//***************************************************************************
unsigned long readwavfile(char *ptr_to_infile, int ntrmin, double *idat, double *qdat )
{
unsigned long i, j, npoints;
int nfft1, nfft2, nh2, i0;
double df;
nfft2=46080; //this is the number of downsampled points that will be returned
nh2=nfft2/2;
if( ntrmin == 2 ) {
nfft1=nfft2*32; //need to downsample by a factor of 32
df=12000.0/nfft1;
i0=1500.0/df+0.5;
npoints=114*12000;
} else if ( ntrmin == 15 ) {
nfft1=nfft2*8*32;
df=12000.0/nfft1;
i0=(1500.0+112.5)/df+0.5;
npoints=8*114*12000;
} else {
fprintf(stderr,"This should not happen\n");
return 1;
}
double *realin;
fftw_complex *fftin, *fftout;
FILE *fp;
short int *buf2;
buf2 = malloc(npoints*sizeof(short int));
fp = fopen(ptr_to_infile,"rb");
if (fp == NULL) {
fprintf(stderr, "Cannot open data file '%s'\n", ptr_to_infile);
return 1;
}
nr=fread(buf2,2,22,fp); //Read and ignore header
nr=fread(buf2,2,npoints,fp); //Read raw data
fclose(fp);
realin=(double*) fftw_malloc(sizeof(double)*nfft1);
fftout=(fftw_complex*) fftw_malloc(sizeof(fftw_complex)*nfft1);
PLAN1 = fftw_plan_dft_r2c_1d(nfft1, realin, fftout, PATIENCE);
for (i=0; i<npoints; i++) {
realin[i]=buf2[i]/32768.0;
}
for (i=npoints; i<nfft1; i++) {
realin[i]=0.0;
}
free(buf2);
fftw_execute(PLAN1);
fftw_free(realin);
fftin=(fftw_complex*) fftw_malloc(sizeof(fftw_complex)*nfft2);
for (i=0; i<nfft2; i++) {
j=i0+i;
if( i>nh2 ) j=j-nfft2;
fftin[i][0]=fftout[j][0];
fftin[i][1]=fftout[j][1];
}
fftw_free(fftout);
fftout=(fftw_complex*) fftw_malloc(sizeof(fftw_complex)*nfft2);
PLAN2 = fftw_plan_dft_1d(nfft2, fftin, fftout, FFTW_BACKWARD, PATIENCE);
fftw_execute(PLAN2);
for (i=0; i<nfft2; i++) {
idat[i]=fftout[i][0]/1000.0;
qdat[i]=fftout[i][1]/1000.0;
}
fftw_free(fftin);
fftw_free(fftout);
return nfft2;
}
//***************************************************************************
void sync_and_demodulate(double *id, double *qd, long np,
unsigned char *symbols, float *f1, float fstep,
int *shift1, int lagmin, int lagmax, int lagstep,
float *drift1, int symfac, float *sync, int mode)
{
/***********************************************************************
* mode = 0: no frequency or drift search. find best time lag. *
* 1: no time lag or drift search. find best frequency. *
* 2: no frequency or time lag search. calculate soft-decision *
* symbols using passed frequency and shift. *
************************************************************************/
float dt=1.0/375.0, df=375.0/256.0, fbest=0.0;
int i, j, k;
double pi=4.*atan(1.0),twopidt;
float f0=0.0,fp,fplast=-10000.0,ss;
int lag;
double i0[162],q0[162],i1[162],q1[162],i2[162],q2[162],i3[162],q3[162];
double p0,p1,p2,p3,cmet,totp,syncmax,fac;
double c0[256],s0[256],c1[256],s1[256],c2[256],s2[256],c3[256],s3[256];
double dphi0, cdphi0, sdphi0, dphi1, cdphi1, sdphi1, dphi2, cdphi2, sdphi2,
dphi3, cdphi3, sdphi3;
float fsum=0.0, f2sum=0.0, fsymb[162];
int best_shift = 0, ifreq;
int ifmin=0, ifmax=0;
syncmax=-1e30;
if( mode == 0 ) {ifmin=0; ifmax=0; fstep=0.0; f0=*f1;}
if( mode == 1 ) {lagmin=*shift1;lagmax=*shift1;ifmin=-5;ifmax=5;f0=*f1;}
if( mode == 2 ) {lagmin=*shift1;lagmax=*shift1;ifmin=0;ifmax=0;f0=*f1;}
twopidt=2*pi*dt;
for(ifreq=ifmin; ifreq<=ifmax; ifreq++) {
f0=*f1+ifreq*fstep;
for(lag=lagmin; lag<=lagmax; lag=lag+lagstep) {
ss=0.0;
totp=0.0;
for (i=0; i<162; i++) {
fp = f0 + ((float)*drift1/2.0)*((float)i-81.0)/81.0;
if( i==0 || (fp != fplast) ) { // only calculate sin/cos if necessary
dphi0=2*pi*(fp-1.5*df)*dt;
cdphi0=cos(dphi0);
sdphi0=sin(dphi0);
dphi1=twopidt*(fp-0.5*df);
cdphi1=cos(dphi1);
sdphi1=sin(dphi1);
dphi2=twopidt*(fp+0.5*df);
cdphi2=cos(dphi2);
sdphi2=sin(dphi2);
dphi3=twopidt*(fp+1.5*df);
cdphi3=cos(dphi3);
sdphi3=sin(dphi3);
c0[0]=1; s0[0]=0;
c1[0]=1; s1[0]=0;
c2[0]=1; s2[0]=0;
c3[0]=1; s3[0]=0;
for (j=1; j<256; j++) {
c0[j]=c0[j-1]*cdphi0 - s0[j-1]*sdphi0;
s0[j]=c0[j-1]*sdphi0 + s0[j-1]*cdphi0;
c1[j]=c1[j-1]*cdphi1 - s1[j-1]*sdphi1;
s1[j]=c1[j-1]*sdphi1 + s1[j-1]*cdphi1;
c2[j]=c2[j-1]*cdphi2 - s2[j-1]*sdphi2;
s2[j]=c2[j-1]*sdphi2 + s2[j-1]*cdphi2;
c3[j]=c3[j-1]*cdphi3 - s3[j-1]*sdphi3;
s3[j]=c3[j-1]*sdphi3 + s3[j-1]*cdphi3;
}
fplast = fp;
}
i0[i]=0.0; q0[i]=0.0;
i1[i]=0.0; q1[i]=0.0;
i2[i]=0.0; q2[i]=0.0;
i3[i]=0.0; q3[i]=0.0;
for (j=0; j<256; j++) {
k=lag+i*256+j;
if( (k>0) & (k<np) ) {
i0[i]=i0[i] + id[k]*c0[j] + qd[k]*s0[j];
q0[i]=q0[i] - id[k]*s0[j] + qd[k]*c0[j];
i1[i]=i1[i] + id[k]*c1[j] + qd[k]*s1[j];
q1[i]=q1[i] - id[k]*s1[j] + qd[k]*c1[j];
i2[i]=i2[i] + id[k]*c2[j] + qd[k]*s2[j];
q2[i]=q2[i] - id[k]*s2[j] + qd[k]*c2[j];
i3[i]=i3[i] + id[k]*c3[j] + qd[k]*s3[j];
q3[i]=q3[i] - id[k]*s3[j] + qd[k]*c3[j];
}
}
p0=i0[i]*i0[i] + q0[i]*q0[i];
p1=i1[i]*i1[i] + q1[i]*q1[i];
p2=i2[i]*i2[i] + q2[i]*q2[i];
p3=i3[i]*i3[i] + q3[i]*q3[i];
p0=sqrt(p0);
p1=sqrt(p1);
p2=sqrt(p2);
p3=sqrt(p3);
totp=totp+p0+p1+p2+p3;
cmet=(p1+p3)-(p0+p2);
ss=ss+cmet*(2*pr3[i]-1);
if( mode == 2) { //Compute soft symbols
if(pr3[i]) {
fsymb[i]=p3-p1;
} else {
fsymb[i]=p2-p0;
}
}
}
if( ss/totp > syncmax ) { //Save best parameters
syncmax=ss/totp;
best_shift=lag;
fbest=f0;
}
} // lag loop
} //freq loop
if( mode <=1 ) { //Send best params back to caller
*sync=syncmax;
*shift1=best_shift;
*f1=fbest;
return;
}
if( mode == 2 ) {
*sync=syncmax;
for (i=0; i<162; i++) { //Normalize the soft symbols
fsum=fsum+fsymb[i]/162.0;
f2sum=f2sum+fsymb[i]*fsymb[i]/162.0;
}
fac=sqrt(f2sum-fsum*fsum);
for (i=0; i<162; i++) {
fsymb[i]=symfac*fsymb[i]/fac;
if( fsymb[i] > 127) fsymb[i]=127.0;
if( fsymb[i] < -128 ) fsymb[i]=-128.0;
symbols[i]=fsymb[i] + 128;
}
return;
}
return;
}
//***************************************************************************
void usage(void)
{
printf("Usage: wsprd [options...] infile\n");
printf(" infile must have suffix .wav or .c2\n");
printf("\n");
printf("Options:\n");
printf(" -a <path> path to writeable data files, default=\".\"\n");
printf(" -e x (x is transceiver dial frequency error in Hz)\n");
printf(" -f x (x is transceiver dial frequency in MHz)\n");
// blanking is not yet implemented. The options are accepted for compatibility
// with development version of wsprd.
// printf(" -t n (n is blanking duration in milliseconds)\n");
// printf(" -b n (n is pct of time that is blanked)\n");
printf(" -H do not use (or update) the hash table\n");
printf(" -m decode wspr-15 .wav file\n");
printf(" -n write noise estimates to file noise.dat\n");
printf(" -q quick mode - doesn't dig deep for weak signals\n");
printf(" -s slow mode - much slower, yields a few more decodes\n");
printf(" -v verbose mode\n");
printf(" -w wideband mode - decode signals within +/- 150 Hz of center\n");
printf(" -z x (x is fano metric table bias, default is 0.42)\n");
}
//***************************************************************************
int main(int argc, char *argv[])
{
extern char *optarg;
extern int optind;
int i,j,k;
unsigned char *symbols, *decdata;
signed char message[]={-9,13,-35,123,57,-39,64,0,0,0,0};
char *callsign,*grid,*grid6, *call_loc_pow, *cdbm;
char *ptr_to_infile,*ptr_to_infile_suffix;
char *data_dir=NULL;
char wisdom_fname[200],all_fname[200],spots_fname[200];
char timer_fname[200],hash_fname[200];
char uttime[5],date[7];
int c,delta,maxpts=65536,verbose=0,quickmode=0,writenoise=0,usehashtable=1,wspr_type=2;
int shift1, lagmin, lagmax, lagstep, worth_a_try, not_decoded;
unsigned int nbits;
unsigned int npoints, metric, maxcycles, cycles, maxnp;
float df=375.0/256.0/2;
float freq0[200],snr0[200],drift0[200],sync0[200];
int shift0[200];
float dt=1.0/375.0, dt_print;
double dialfreq_cmdline=0.0, dialfreq, freq_print;
float dialfreq_error=0.0;
float fmin=-110, fmax=110;
float f1, fstep, sync1, drift1, tblank=0, fblank=0;
double *idat, *qdat;
clock_t t0,t00;
double tfano=0.0,treadwav=0.0,tcandidates=0.0,tsync0=0.0;
double tsync1=0.0,tsync2=0.0,ttotal=0.0;
// Parameters used for performance-tuning:
maxcycles=10000; //Fano timeout limit
double minsync1=0.10; //First sync limit
double minsync2=0.12; //Second sync limit
int iifac=3; //Step size in final DT peakup
int symfac=50; //Soft-symbol normalizing factor
int maxdrift=4; //Maximum (+/-) drift
double minrms=52.0 * (symfac/64.0); //Final test for plausible decoding
delta=60; //Fano threshold step
t00=clock();
fftw_complex *fftin, *fftout;
#include "./metric_tables.c"
int mettab[2][256];
float bias=0.42;
idat=malloc(sizeof(double)*maxpts);
qdat=malloc(sizeof(double)*maxpts);
while ( (c = getopt(argc, argv, "a:b:e:f:Hmnqst:wvz:")) !=-1 ) {
switch (c) {
case 'a':
data_dir = optarg;
break;
case 'b':
fblank = strtof(optarg,NULL);
break;
case 'e':
dialfreq_error = strtof(optarg,NULL); // units of Hz
// dialfreq_error = dial reading - actual, correct frequency
break;
case 'f':
dialfreq_cmdline = strtod(optarg,NULL); // units of MHz
break;
case 'H':
usehashtable = 0;
break;
case 'm':
wspr_type = 15;
break;
case 'n':
writenoise = 1;
break;
case 'q':
quickmode = 1;
break;
case 's':
maxcycles=20000;
iifac=1;
break;
case 't':
tblank = strtof(optarg,NULL);
break;
case 'v':
verbose = 1;
break;
case 'w':
fmin=-150.0;
fmax=150.0;
break;
case 'z':
bias=strtof(optarg,NULL); //fano metric bias (default is 0.42)
break;
case '?':
usage();
return 1;
}
}
if( optind+1 > argc) {
usage();
return 1;
} else {
ptr_to_infile=argv[optind];
}
// setup metric table
for(i=0; i<256; i++) {
mettab[0][i]=round( 10*(metric_tables[2][i]-bias) );
mettab[1][i]=round( 10*(metric_tables[2][255-i]-bias) );
}
FILE *fp_fftw_wisdom_file, *fall_wspr, *fwsprd, *fhash, *ftimer;
strcpy(wisdom_fname,".");
strcpy(all_fname,".");
strcpy(spots_fname,".");
strcpy(timer_fname,".");
strcpy(hash_fname,".");
if(data_dir != NULL) {
strcpy(wisdom_fname,data_dir);
strcpy(all_fname,data_dir);
strcpy(spots_fname,data_dir);
strcpy(timer_fname,data_dir);
strcpy(hash_fname,data_dir);
}
strncat(wisdom_fname,"/wspr_wisdom.dat",20);
strncat(all_fname,"/ALL_WSPR.TXT",20);
strncat(spots_fname,"/wspr_spots.txt",20);
strncat(timer_fname,"/wspr_timer.out",20);
strncat(hash_fname,"/hashtable.txt",20);
if ((fp_fftw_wisdom_file = fopen(wisdom_fname, "r"))) { //Open FFTW wisdom
fftw_import_wisdom_from_file(fp_fftw_wisdom_file);
fclose(fp_fftw_wisdom_file);
}
fall_wspr=fopen(all_fname,"a");
fwsprd=fopen(spots_fname,"w");
// FILE *fdiag;
// fdiag=fopen("wsprd_diag","a");
if((ftimer=fopen(timer_fname,"r"))) {
//Accumulate timing data
nr=fscanf(ftimer,"%lf %lf %lf %lf %lf %lf %lf",
&treadwav,&tcandidates,&tsync0,&tsync1,&tsync2,&tfano,&ttotal);
fclose(ftimer);
}
ftimer=fopen(timer_fname,"w");
if( strstr(ptr_to_infile,".wav") ) {
ptr_to_infile_suffix=strstr(ptr_to_infile,".wav");
t0 = clock();
npoints=readwavfile(ptr_to_infile, wspr_type, idat, qdat);
treadwav += (double)(clock()-t0)/CLOCKS_PER_SEC;
if( npoints == 1 ) {
return 1;
}
dialfreq=dialfreq_cmdline - (dialfreq_error*1.0e-06);
} else if ( strstr(ptr_to_infile,".c2") !=0 ) {
ptr_to_infile_suffix=strstr(ptr_to_infile,".c2");
npoints=readc2file(ptr_to_infile, idat, qdat, &dialfreq, &wspr_type);
if( npoints == 1 ) {
return 1;
}
dialfreq -= (dialfreq_error*1.0e-06);
} else {
printf("Error: Failed to open %s\n",ptr_to_infile);
printf("WSPR file must have suffix .wav or .c2\n");
return 1;
}
// Parse date and time from given filename
strncpy(date,ptr_to_infile_suffix-11,6);
strncpy(uttime,ptr_to_infile_suffix-4,4);
date[6]='\0';
uttime[4]='\0';
// Do windowed ffts over 2 symbols, stepped by half symbols
int nffts=4*floor(npoints/512)-1;
fftin=(fftw_complex*) fftw_malloc(sizeof(fftw_complex)*512);
fftout=(fftw_complex*) fftw_malloc(sizeof(fftw_complex)*512);
PLAN3 = fftw_plan_dft_1d(512, fftin, fftout, FFTW_FORWARD, PATIENCE);
float ps[512][nffts];
float w[512];
for(i=0; i<512; i++) {
w[i]=sin(0.006147931*i);
}
memset(ps,0.0, sizeof(float)*512*nffts);
for (i=0; i<nffts; i++) {
for(j=0; j<512; j++ ) {
k=i*128+j;
fftin[j][0]=idat[k] * w[j];
fftin[j][1]=qdat[k] * w[j];
}
fftw_execute(PLAN3);
for (j=0; j<512; j++ ) {
k=j+256;
if( k>511 )
k=k-512;
ps[j][i]=fftout[k][0]*fftout[k][0]+fftout[k][1]*fftout[k][1];
}
}
fftw_free(fftin);
fftw_free(fftout);
// Compute average spectrum
float psavg[512];
memset(psavg,0.0, sizeof(float)*512);
for (i=0; i<nffts; i++) {
for (j=0; j<512; j++) {
psavg[j]=psavg[j]+ps[j][i];
}
}
// Smooth with 7-point window and limit spectrum to +/-150 Hz
int window[7]={1,1,1,1,1,1,1};
float smspec[411];
for (i=0; i<411; i++) {
smspec[i]=0.0;
for(j=-3; j<=3; j++) {
k=256-205+i+j;
smspec[i]=smspec[i]+window[j+3]*psavg[k];
}
}
// Sort spectrum values, then pick off noise level as a percentile
float tmpsort[411];
for (j=0; j<411; j++) {
tmpsort[j]=smspec[j];
}
qsort(tmpsort, 411, sizeof(float), floatcomp);
// Noise level of spectrum is estimated as 123/411= 30'th percentile
float noise_level = tmpsort[122];
/* Renormalize spectrum so that (large) peaks represent an estimate of snr.
* We know from experience that threshold snr is near -7dB in wspr bandwidth,
* corresponding to -7-26.3=-33.3dB in 2500 Hz bandwidth.
* The corresponding threshold is -42.3 dB in 2500 Hz bandwidth for WSPR-15. */
float min_snr, snr_scaling_factor;
min_snr = pow(10.0,-7.0/10.0); //this is min snr in wspr bw
if( wspr_type == 2 ) {
snr_scaling_factor=26.3;
} else {
snr_scaling_factor=35.3;
}
for (j=0; j<411; j++) {
smspec[j]=smspec[j]/noise_level - 1.0;
if( smspec[j] < min_snr) smspec[j]=0.1;
continue;
}
// Find all local maxima in smoothed spectrum.
for (i=0; i<200; i++) {
freq0[i]=0.0;
snr0[i]=0.0;
drift0[i]=0.0;
shift0[i]=0;
sync0[i]=0.0;
}
int npk=0;
for(j=1; j<410; j++) {
if((smspec[j]>smspec[j-1]) && (smspec[j]>smspec[j+1]) && (npk<200)) {
freq0[npk]=(j-205)*df;
snr0[npk]=10*log10(smspec[j])-snr_scaling_factor;
npk++;
}
}
// Compute corrected fmin, fmax, accounting for dial frequency error
fmin += dialfreq_error; // dialfreq_error is in units of Hz
fmax += dialfreq_error;
// Don't waste time on signals outside of the range [fmin,fmax].
i=0;
for( j=0; j<npk; j++) {
if( freq0[j] >= fmin && freq0[j] <= fmax ) {
freq0[i]=freq0[j];
snr0[i]=snr0[j];
i++;
}
}
npk=i;
t0=clock();
/* Make coarse estimates of shift (DT), freq, and drift
* Look for time offsets up to +/- 8 symbols (about +/- 5.4 s) relative
to nominal start time, which is 2 seconds into the file
* Calculates shift relative to the beginning of the file
* Negative shifts mean that signal started before start of file
* The program prints DT = shift-2 s
* Shifts that cause sync vector to fall off of either end of the data
vector are accommodated by "partial decoding", such that missing
symbols produce a soft-decision symbol value of 128
* The frequency drift model is linear, deviation of +/- drift/2 over the
span of 162 symbols, with deviation equal to 0 at the center of the
signal vector.
*/
int idrift,ifr,if0,ifd,k0;
int kindex;
float smax,ss,pow,p0,p1,p2,p3;
for(j=0; j<npk; j++) { //For each candidate...
smax=-1e30;
if0=freq0[j]/df+256;
for (ifr=if0-1; ifr<=if0+1; ifr++) { //Freq search
for( k0=-10; k0<22; k0++) { //Time search
for (idrift=-maxdrift; idrift<=maxdrift; idrift++) { //Drift search
ss=0.0;
pow=0.0;
for (k=0; k<162; k++) { //Sum over symbols
ifd=ifr+((float)k-81.0)/81.0*( (float)idrift )/(2.0*df);
kindex=k0+2*k;
if( kindex < nffts ) {
p0=ps[ifd-3][kindex];
p1=ps[ifd-1][kindex];
p2=ps[ifd+1][kindex];
p3=ps[ifd+3][kindex];
p0=sqrt(p0);
p1=sqrt(p1);
p2=sqrt(p2);
p3=sqrt(p3);
ss=ss+(2*pr3[k]-1)*((p1+p3)-(p0+p2));
pow=pow+p0+p1+p2+p3;
sync1=ss/pow;
}
}
if( sync1 > smax ) { //Save coarse parameters
smax=sync1;
shift0[j]=128*(k0+1);
drift0[j]=idrift;
freq0[j]=(ifr-256)*df;
sync0[j]=sync1;
}
}
}
}
}
tcandidates += (double)(clock()-t0)/CLOCKS_PER_SEC;
nbits=81;
symbols=malloc(sizeof(char)*nbits*2);
memset(symbols,0,sizeof(char)*nbits*2);
decdata=malloc((nbits+7)/8);
grid=malloc(sizeof(char)*5);
grid6=malloc(sizeof(char)*7);
callsign=malloc(sizeof(char)*13);
call_loc_pow=malloc(sizeof(char)*23);
cdbm=malloc(sizeof(char)*3);
float allfreqs[npk];
memset(allfreqs,0,sizeof(float)*npk);
char allcalls[npk][13];
memset(allcalls,0,sizeof(char)*npk*13);
memset(grid,0,sizeof(char)*5);
memset(grid6,0,sizeof(char)*7);
memset(callsign,0,sizeof(char)*13);
memset(call_loc_pow,0,sizeof(char)*23);
memset(cdbm,0,sizeof(char)*3);
char hashtab[32768][13];
memset(hashtab,0,sizeof(char)*32768*13);
int nh;
if( usehashtable ) {
char line[80], hcall[12];
if( (fhash=fopen(hash_fname,"r+")) ) {
while (fgets(line, sizeof(line), fhash) != NULL) {
sscanf(line,"%d %s",&nh,hcall);
strcpy(*hashtab+nh*13,hcall);
}
} else {
fhash=fopen(hash_fname,"w+");
}
fclose(fhash);
}
int uniques=0, noprint=0;
/*
Refine the estimates of freq, shift using sync as a metric.
Sync is calculated such that it is a float taking values in the range
[0.0,1.0].
Function sync_and_demodulate has three modes of operation
mode is the last argument:
0 = no frequency or drift search. find best time lag.
1 = no time lag or drift search. find best frequency.
2 = no frequency or time lag search. Calculate soft-decision
symbols using passed frequency and shift.
NB: best possibility for OpenMP may be here: several worker threads
could each work on one candidate at a time.
*/
for (j=0; j<npk; j++) {
f1=freq0[j];
drift1=drift0[j];
shift1=shift0[j];
sync1=sync0[j];
// Fine search for best sync lag (mode 0)
fstep=0.0;
lagmin=shift1-144;
lagmax=shift1+144;
lagstep=8;
if(quickmode) lagstep=16;
t0 = clock();
sync_and_demodulate(idat, qdat, npoints, symbols, &f1, fstep, &shift1,
lagmin, lagmax, lagstep, &drift1, symfac, &sync1, 0);
tsync0 += (double)(clock()-t0)/CLOCKS_PER_SEC;
// Fine search for frequency peak (mode 1)
fstep=0.1;
t0 = clock();
sync_and_demodulate(idat, qdat, npoints, symbols, &f1, fstep, &shift1,
lagmin, lagmax, lagstep, &drift1, symfac, &sync1, 1);
tsync1 += (double)(clock()-t0)/CLOCKS_PER_SEC;
if( sync1 > minsync1 ) {
worth_a_try = 1;
} else {
worth_a_try = 0;
}
int idt=0, ii=0, jiggered_shift;
double y,sq,rms;
not_decoded=1;
while ( worth_a_try && not_decoded && idt<=(128/iifac)) {
ii=(idt+1)/2;
if( idt%2 == 1 ) ii=-ii;
ii=iifac*ii;
jiggered_shift=shift1+ii;
// Use mode 2 to get soft-decision symbols
t0 = clock();
sync_and_demodulate(idat, qdat, npoints, symbols, &f1, fstep,
&jiggered_shift, lagmin, lagmax, lagstep, &drift1, symfac,
&sync1, 2);
tsync2 += (double)(clock()-t0)/CLOCKS_PER_SEC;
sq=0.0;
for(i=0; i<162; i++) {
y=(double)symbols[i] - 128.0;
sq += y*y;
}
rms=sqrt(sq/162.0);
if((sync1 > minsync2) && (rms > minrms)) {
deinterleave(symbols);
t0 = clock();
not_decoded = fano(&metric,&cycles,&maxnp,decdata,symbols,nbits,
mettab,delta,maxcycles);
tfano += (double)(clock()-t0)/CLOCKS_PER_SEC;
/* ### Used for timing tests:
if(not_decoded) fprintf(fdiag,
"%6s %4s %4.1f %3.0f %4.1f %10.7f %-18s %2d %5u %4d %6.1f %2d\n",
date,uttime,sync1*10,snr0[j], shift1*dt-2.0, dialfreq+(1500+f1)/1e6,
"@ ", (int)drift1, cycles/81, ii, rms, maxnp);
*/
}
idt++;
if( quickmode ) break;
}
if( worth_a_try && !not_decoded ) {
for(i=0; i<11; i++) {
if( decdata[i]>127 ) {
message[i]=decdata[i]-256;
} else {
message[i]=decdata[i];
}
}
// Unpack the decoded message, update the hashtable, apply
// sanity checks on grid and power, and return
// call_loc_pow string and also callsign (for de-duping).
noprint=unpk_(message,hashtab,call_loc_pow,callsign);
// Remove dupes (same callsign and freq within 1 Hz)
int dupe=0;
for (i=0; i<npk; i++) {
if(!strcmp(callsign,allcalls[i]) &&
(fabs(f1-allfreqs[i]) <1.0)) dupe=1;
}
if( (verbose || !dupe) && !noprint) {
uniques++;
strcpy(allcalls[uniques],callsign);
allfreqs[uniques]=f1;
// Add an extra space at the end of each line so that wspr-x doesn't
// truncate the power (TNX to DL8FCL!)
if( wspr_type == 15 ) {
freq_print=dialfreq+(1500+112.5+f1/8.0)/1e6;
dt_print=shift1*8*dt-2.0;
} else {
freq_print=dialfreq+(1500+f1)/1e6;
dt_print=shift1*dt-2.0;
}
printf("%4s %3.0f %4.1f %10.6f %2d %-s \n",
uttime, snr0[j],dt_print,freq_print,
(int)drift1, call_loc_pow);
fprintf(fall_wspr,
"%6s %4s %3.0f %3.0f %4.1f %10.7f %-22s %2d %5u %4d\n",
date,uttime,sync1*10,snr0[j],
dt_print, freq_print,
call_loc_pow, (int)drift1, cycles/81, ii);
fprintf(fwsprd,"%6s %4s %3d %3.0f %4.1f %10.6f %-22s %2d %5u %4d\n",
date,uttime,(int)(sync1*10),snr0[j],
dt_print, freq_print,
call_loc_pow, (int)drift1, cycles/81, ii);
/* For timing tests
fprintf(fdiag,
"%6s %4s %4.1f %3.0f %4.1f %10.7f %-18s %2d %5u %4d %6.1f\n",
date,uttime,sync1*10,snr0[j],
shift1*dt-2.0, dialfreq+(1500+f1)/1e6,
call_loc_pow, (int)drift1, cycles/81, ii, rms);
*/
}
}
}
printf("<DecodeFinished>\n");
if ((fp_fftw_wisdom_file = fopen(wisdom_fname, "w"))) {
fftw_export_wisdom_to_file(fp_fftw_wisdom_file);
fclose(fp_fftw_wisdom_file);
}
ttotal += (double)(clock()-t00)/CLOCKS_PER_SEC;
fprintf(ftimer,"%7.2f %7.2f %7.2f %7.2f %7.2f %7.2f %7.2f\n\n",
treadwav,tcandidates,tsync0,tsync1,tsync2,tfano,ttotal);
fprintf(ftimer,"Code segment Seconds Frac\n");
fprintf(ftimer,"-----------------------------------\n");
fprintf(ftimer,"readwavfile %7.2f %7.2f\n",treadwav,treadwav/ttotal);
fprintf(ftimer,"Coarse DT f0 f1 %7.2f %7.2f\n",tcandidates,
tcandidates/ttotal);
fprintf(ftimer,"sync_and_demod(0) %7.2f %7.2f\n",tsync0,tsync0/ttotal);
fprintf(ftimer,"sync_and_demod(1) %7.2f %7.2f\n",tsync1,tsync1/ttotal);
fprintf(ftimer,"sync_and_demod(2) %7.2f %7.2f\n",tsync2,tsync2/ttotal);
fprintf(ftimer,"Fano decoder %7.2f %7.2f\n",tfano,tfano/ttotal);
fprintf(ftimer,"-----------------------------------\n");
fprintf(ftimer,"Total %7.2f %7.2f\n",ttotal,1.0);
fclose(fall_wspr);
fclose(fwsprd);
// fclose(fdiag);
fclose(ftimer);
fftw_destroy_plan(PLAN1);
fftw_destroy_plan(PLAN2);
fftw_destroy_plan(PLAN3);
if( usehashtable ) {
fhash=fopen(hash_fname,"w");
for (i=0; i<32768; i++) {
if( strncmp(hashtab[i],"\0",1) != 0 ) {
fprintf(fhash,"%5d %s\n",i,*hashtab+i*13);
}
}
fclose(fhash);
}
if(fblank+tblank+writenoise == 999) return -1; //Silence compiler warning
return 0;
}
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