yafox
/
minimodem-mirror
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

fsk cleanup

This commit is contained in:
Kamal Mostafa 2011-06-05 08:49:06 -07:00
parent cd6ab7f77d
commit 2ea1085b45
1 changed files with 15 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

29
src/fsk.c
View File

@ -34,6 +34,8 @@ struct fsk_plan {
unsigned int n_frame_bits; unsigned int n_frame_bits;
#ifdef USE_FFT #ifdef USE_FFT
int fftsize; // fftw wants this to be signed. why? int fftsize; // fftw wants this to be signed. why?
unsigned int nbands;
unsigned int band_width;
unsigned int b_mark; unsigned int b_mark;
unsigned int b_space; unsigned int b_space;
fftwf_plan fftplan; fftwf_plan fftplan;
@ -66,17 +68,17 @@ fsk_plan_new(
fskp->n_frame_bits = fskp->n_data_bits + 3; fskp->n_frame_bits = fskp->n_data_bits + 3;
#ifdef USE_FFT #ifdef USE_FFT
unsigned int fft_bw = filter_bw; fskp->band_width = filter_bw;
float fft_half_bw = (float)fft_bw / 2.0; float fft_half_bw = (float)fskp->band_width / 2.0;
fskp->fftsize = (sample_rate + fft_half_bw) / fft_bw; fskp->fftsize = (sample_rate + fft_half_bw) / fskp->band_width;
unsigned int nbands = fskp->fftsize / 2 + 1; fskp->nbands = fskp->fftsize / 2 + 1;
fskp->b_mark = (f_mark + fft_half_bw) / fft_bw; fskp->b_mark = (f_mark + fft_half_bw) / fskp->band_width;
fskp->b_space = (f_space + fft_half_bw) / fft_bw; fskp->b_space = (f_space + fft_half_bw) / fskp->band_width;
if ( fskp->b_mark >= nbands || fskp->b_space >= nbands ) { if ( fskp->b_mark >= fskp->nbands || fskp->b_space >= fskp->nbands ) {
fprintf(stderr, "b_mark=%u or b_space=%u is invalid (nbands=%u)\n", fprintf(stderr, "b_mark=%u or b_space=%u is invalid (nbands=%u)\n",
fskp->b_mark, fskp->b_space, nbands); fskp->b_mark, fskp->b_space, fskp->nbands);
free(fskp); free(fskp);
errno = EINVAL; errno = EINVAL;
return NULL; return NULL;
@ -90,13 +92,13 @@ fsk_plan_new(
// FIXME check these: // FIXME check these:
fskp->fftin = fftwf_malloc(fskp->fftsize * sizeof(float) * pa_nchannels); fskp->fftin = fftwf_malloc(fskp->fftsize * sizeof(float) * pa_nchannels);
fskp->fftout = fftwf_malloc(nbands * sizeof(fftwf_complex) * pa_nchannels); fskp->fftout = fftwf_malloc(fskp->nbands * sizeof(fftwf_complex) * pa_nchannels);
/* complex fftw plan, works for N channels: */ /* complex fftw plan, works for N channels: */
fskp->fftplan = fftwf_plan_many_dft_r2c( fskp->fftplan = fftwf_plan_many_dft_r2c(
/*rank*/1, &fskp->fftsize, /*howmany*/pa_nchannels, /*rank*/1, &fskp->fftsize, /*howmany*/pa_nchannels,
fskp->fftin, NULL, /*istride*/pa_nchannels, /*idist*/1, fskp->fftin, NULL, /*istride*/pa_nchannels, /*idist*/1,
fskp->fftout, NULL, /*ostride*/1, /*odist*/nbands, fskp->fftout, NULL, /*ostride*/1, /*odist*/fskp->nbands,
FFTW_ESTIMATE); FFTW_ESTIMATE);
if ( !fskp->fftplan ) { if ( !fskp->fftplan ) {
@ -136,7 +138,7 @@ static void
fsk_bit_analyze( fsk_plan *fskp, float *samples, unsigned int bit_nsamples, fsk_bit_analyze( fsk_plan *fskp, float *samples, unsigned int bit_nsamples,
unsigned int *bit_outp, float *bit_strength_outp) unsigned int *bit_outp, float *bit_strength_outp)
{ {
unsigned int pa_nchannels = 1; unsigned int pa_nchannels = 1; // FIXME
bzero(fskp->fftin, (fskp->fftsize * sizeof(float) * pa_nchannels)); bzero(fskp->fftin, (fskp->fftsize * sizeof(float) * pa_nchannels));
memcpy(fskp->fftin, samples, bit_nsamples * sizeof(float)); memcpy(fskp->fftin, samples, bit_nsamples * sizeof(float));
fftwf_execute(fskp->fftplan); fftwf_execute(fskp->fftplan);
@ -146,8 +148,8 @@ fsk_bit_analyze( fsk_plan *fskp, float *samples, unsigned int bit_nsamples,
*bit_outp = mag_mark > mag_space ? 1 : 0; // mark==1, space==0 *bit_outp = mag_mark > mag_space ? 1 : 0; // mark==1, space==0
*bit_strength_outp = fabs(mag_mark - mag_space); *bit_strength_outp = fabs(mag_mark - mag_space);
debug_log( "\t%.2f %.2f %s bit=%u bit_strength=%.2f\n", debug_log( "\t%.2f %.2f %s bit=%u bit_strength=%.2f\n",
*mag_mark_outp, *mag_space_outp, mag_mark, mag_space,
*mag_mark_outp > *mag_space_outp ? "mark " : " space", mag_mark > mag_space ? "mark " : " space",
*bit_outp, *bit_strength_outp); *bit_outp, *bit_strength_outp);
} }
@ -407,7 +409,6 @@ main( int argc, char*argv[] )
if ((ret=simpleaudio_read(sa, read_bufptr, read_nsamples)) <= 0) if ((ret=simpleaudio_read(sa, read_bufptr, read_nsamples)) <= 0)
break; break;
// carrier_nsamples += read_nsamples;
debug_log( "--------------------------\n"); debug_log( "--------------------------\n");