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DADA format implementation

pull/10/head
Cees Bassa 2014-11-27 18:20:03 +01:00
parent 3511a50c3a
commit 34c9385418
1 changed files with 88 additions and 17 deletions
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105
rffft.c
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@ -18,6 +18,8 @@ void usage(void)
printf("-t <tint> Integration time [1s]\n");
printf("-n <nsub> Number of integrations per file [60]\n");
printf("-m <use> Use every mth integration [1]\n");
printf("-l Treat as lower subband\n");
printf("-d Treat input as dada file\n");
printf("-h This help\n");
return;
@ -26,11 +28,13 @@ void usage(void)
int main(int argc,char *argv[])
{
int i,j,k,l,m,nchan,nint=1,arg=0,nbytes,nsub=60,flag,nuse=1;
int lowersubband=0,dadaformat=0;
fftwf_complex *c,*d;
fftwf_plan fft;
FILE *infile,*outfile;
char infname[128],outfname[128],path[64]="/data/record",prefix[32]="";
int16_t *ibuf;
char *cbuf;
float *z,length,fchan=100.0,tint=1.0;
double freq,samp_rate;
struct timeval start,end;
@ -38,7 +42,7 @@ int main(int argc,char *argv[])
// Read arguments
if (argc>1) {
while ((arg=getopt(argc,argv,"i:f:s:c:t:p:n:hm:"))!=-1) {
while ((arg=getopt(argc,argv,"i:f:s:c:t:p:n:hm:ld"))!=-1) {
switch(arg) {
case 'i':
@ -61,6 +65,14 @@ int main(int argc,char *argv[])
fchan=atof(optarg);
break;
case 'l':
lowersubband=1;
break;
case 'd':
dadaformat=1;
break;
case 'n':
nsub=atoi(optarg);
break;
@ -95,6 +107,7 @@ int main(int argc,char *argv[])
// Dump statistics
printf("Filename: %s\n",infname);
printf("Frequency: %f MHz\n",freq*1e-6);
printf("Bandwidth: %f MHz\n",samp_rate*1e-6);
printf("Sampling time: %f us\n",1e6/samp_rate);
printf("Number of channels: %d\n",nchan);
@ -108,6 +121,10 @@ int main(int argc,char *argv[])
d=fftwf_malloc(sizeof(fftwf_complex)*nchan);
ibuf=(int16_t *) malloc(sizeof(int16_t)*2*nchan);
z=(float *) malloc(sizeof(float)*nchan);
// Allocate character buffer
if (dadaformat==1)
cbuf=(char *) malloc(sizeof(char)*4*nchan);
// Plan
fft=fftwf_plan_dft_1d(nchan,c,d,FFTW_FORWARD,FFTW_ESTIMATE);
@ -115,10 +132,18 @@ int main(int argc,char *argv[])
// Create prefix
gettimeofday(&start,0);
strftime(prefix,30,"%Y-%m-%dT%T",gmtime(&start.tv_sec));
// Override if dada format
if (dadaformat==1)
strcpy(prefix,"dada");
// Open file
infile=fopen(infname,"r");
// Read 4096 byte header if dada format
if (dadaformat==1)
nbytes=fread(cbuf,sizeof(char),4096,infile);
// Forever loop
for (m=0;;m++) {
// File name
@ -137,31 +162,75 @@ int main(int argc,char *argv[])
// Integrate
for (j=0;j<nint;j++) {
// nbytes=fread(fbuf,sizeof(float),2*nchan,infile);
nbytes=fread(ibuf,sizeof(int16_t),2*nchan,infile);
if (dadaformat==1)
nbytes=fread(cbuf,sizeof(char),4*nchan,infile);
else
nbytes=fread(ibuf,sizeof(int16_t),2*nchan,infile);
if (nbytes==0)
break;
// Skip buffer
if (j%nuse!=0)
continue;
// Unpack single polarization data
if (dadaformat==0) {
for (i=0;i<nchan;i++) {
c[i][0]=(float) ibuf[2*i]/32768.0;
c[i][1]=(float) ibuf[2*i+1]/32768.0;
}
// Execute
fftwf_execute(fft);
// Unpack
for (i=0;i<nchan;i++) {
c[i][0]=(float) ibuf[2*i]/32768.0;
c[i][1]=(float) ibuf[2*i+1]/32768.0;
}
// Add
for (i=0;i<nchan;i++) {
if (i<nchan/2)
l=i+nchan/2;
else
l=i-nchan/2;
if (lowersubband==1)
l=nchan-l;
z[l]+=d[i][0]*d[i][0]+d[i][1]*d[i][1];
}
} else {
for (i=0;i<nchan;i++) {
c[i][0]=(float) cbuf[4*i]/256.0;
c[i][1]=(float) cbuf[4*i+1]/256.0;
}
// Execute
fftwf_execute(fft);
// Execute
fftwf_execute(fft);
// Add
for (i=0;i<nchan;i++) {
if (i<nchan/2)
l=i+nchan/2;
else
l=i-nchan/2;
if (lowersubband==1)
l=nchan-l;
z[l]+=d[i][0]*d[i][0]+d[i][1]*d[i][1];
}
for (i=0;i<nchan;i++) {
c[i][0]=(float) cbuf[4*i+2]/256.0;
c[i][1]=(float) cbuf[4*i+3]/256.0;
}
// Execute
fftwf_execute(fft);
// Add
for (i=0;i<nchan;i++) {
if (i<nchan/2)
l=i+nchan/2;
else
l=i-nchan/2;
z[l]+=d[i][0]*d[i][0]+d[i][1]*d[i][1];
// Add
for (i=0;i<nchan;i++) {
if (i<nchan/2)
l=i+nchan/2;
else
l=i-nchan/2;
if (lowersubband==1)
l=nchan-l;
z[l]+=d[i][0]*d[i][0]+d[i][1]*d[i][1];
}
}
}
@ -210,6 +279,8 @@ int main(int argc,char *argv[])
fftwf_free(c);
fftwf_free(d);
free(z);
if (dadaformat==1)
free(cbuf);
return 0;
}