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

fsk cleanup

This commit is contained in:
Kamal Mostafa 2011-06-06 21:33:50 -07:00
parent 69a4cddd3e
commit 0509066f34
1 changed files with 9 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

14
src/fsk.c
View File

@ -203,8 +203,10 @@ fsk_frame_decode( fsk_plan *fskp, float *samples, unsigned int frame_nsamples,
* a transient as a start bit, as often results in a single false * a transient as a start bit, as often results in a single false
* character when the mark "leader" tone begins. Require that the * character when the mark "leader" tone begins. Require that the
* diff between start bit and stop bit strength not be "large". */ * diff between start bit and stop bit strength not be "large". */
if ( fabs(s_str-p_str) > (s_str * AVOID_TRANSIENTS) ) if ( fabs(s_str-p_str) > (s_str * AVOID_TRANSIENTS) ) {
debug_log("avoid_transient\n");
return 0.0; return 0.0;
}
#endif #endif
debug_log("\t\tidle "); debug_log("\t\tidle ");
@ -411,6 +413,7 @@ main( int argc, char*argv[] )
*/ */
unsigned int bfsk_mark_f = 1270; unsigned int bfsk_mark_f = 1270;
unsigned int bfsk_space_f = 1070; unsigned int bfsk_space_f = 1070;
unsigned int autodetect_shift = 200;
// band_width = 10; // band_width = 10;
band_width = 100; /* close enough */ band_width = 100; /* close enough */
@ -482,18 +485,19 @@ main( int argc, char*argv[] )
// FIXME?: hardcoded 300 baud trigger for carrier autodetect // FIXME?: hardcoded 300 baud trigger for carrier autodetect
if ( decode_rate <= 300 && carrier_band < 0 ) { if ( decode_rate <= 300 && carrier_band < 0 ) {
unsigned int i; unsigned int i;
for ( i=0; i<read_nsamples; i+=fskp->fftsize ) { for ( i=0; i+fskp->fftsize<=buf_nsamples; i+=fskp->fftsize ) {
carrier_band = fsk_detect_carrier(fskp, carrier_band = fsk_detect_carrier(fskp,
samples+i, fskp->fftsize, samples+i, fskp->fftsize,
CARRIER_AUTODETECT_THRESHOLD); CARRIER_AUTODETECT_THRESHOLD);
if ( carrier_band >= 0 ) if ( carrier_band >= 0 )
break; break;
} }
advance = i; /* set advance, in case we end up continuing */
if ( carrier_band < 0 ) if ( carrier_band < 0 )
continue; continue;
// FIXME: hardcoded -200 Hz shift here (appropriate for 300 baud) // FIXME: hardcoded negative shift
int b_shift = - (float)(200 + fskp->band_width/2.0) int b_shift = - (float)(autodetect_shift + fskp->band_width/2.0)
/ fskp->band_width; / fskp->band_width;
/* only accept a carrier as b_mark if it will not result /* only accept a carrier as b_mark if it will not result
* in a b_space band which is "too low". */ * in a b_space band which is "too low". */
@ -508,7 +512,7 @@ main( int argc, char*argv[] )
debug_log( "--------------------------\n"); debug_log( "--------------------------\n");
// FIXME: explain // FIXME: explain
unsigned int frame_nsamples = nsamples_per_bit * 11; unsigned int frame_nsamples = nsamples_per_bit * fskp->n_frame_bits;
// FIXME: explain // FIXME: explain
unsigned int try_max_nsamples = nsamples_per_bit; unsigned int try_max_nsamples = nsamples_per_bit;