GitHub/dsd-fme
1
0
Fork 0
mirror of https://github.com/lwvmobile/dsd-fme.git synced 2026-11-14 17:57:28 -05:00
Code Issues Packages Projects Releases Wiki Activity

DMR: Fix forced refresh items; #339

Browse Source 
P25: Tweak Tait Talker Alias 7-bit to check for ASCII values >= 0x20;

RTL: Tweaks to RMS;
This commit is contained in:
lwvmobile
2026-02-27 14:44:40 -05:00
parent b7cd501cc1
commit f6f5f80361
3 changed files with 33 additions and 31 deletions
Download Patch File Download Diff File Expand all files Collapse all files

50
src/rtl_sdr_fm.cpp
View File

@@ -465,27 +465,27 @@ void dc_block_filter(struct demod_state *fm)
}
long int rms(int16_t *samples, int len, int step)
/* largely lifted from rtl_power */
{
int i;
long int rms;
long p, t, s;
double dc, err;
long int rms_val;
int64_t p = 0, t = 0;
int64_t s;
p = t = 0L;
for (i=0; i<len; i+=step) {
s = (long)samples[i];
for (i = 0; i < len; i += step) {
s = samples[i];
t += s;
p += s * s;
}
/* correct for dc offset in squares */
dc = (double)(t*step) / (double)len;
err = t * 2 * dc - dc * dc * len;
rms = (long int)sqrt((p-err) / len);
//going with a value that's easy to figure out when its done the thing
if (rms < 0){ rms = 999; }
return rms;
double dc = (double)(t * (int64_t)step) / (double)len;
double err = (double)t * 2.0 * dc - dc * dc * (double)len;
double val = ((double)p - err) / (double)len;
if (val < 0.0) val = 0.0;
rms_val = (long int)sqrt(val);
if (rms_val < 0) rms_val = 999;
return rms_val;
}
void full_demod(struct demod_state *d)
@@ -1214,20 +1214,18 @@ void rtl_dev_tune(dsd_opts * opts, long int frequency)
}
//return RMS value (root means square) power level -- used as soft squelch inside of framesync
static long int prev_rms = 0;
long int rtl_return_rms()
{
long int sr = 0;
// #ifdef __arm__
// sr = 100;
// #else
//debug -- on main machine, lp_len is around 6420, so this probably contributes to very high CPU usage
// fprintf (stderr, "LP_LEN: %d \n", demod.lp_len);
//I've found that just using a sample size of 160 will give us a good approximation without killing the CPU
// sr = rms(demod.lowpassed, demod.lp_len, 1);
sr = rms(demod.lowpassed, 160, 1); //I wonder what a reasonable value would be for #2 (input len) there
// #endif
return (sr);
long int sr = rms(demod.lowpassed, 512, 1); //change 512 to 160 if using too much CPU
// simple 4-block IIR average for stability
sr = (prev_rms * 3 + sr) / 4;
prev_rms = sr;
return sr;
}
//simple function to clear the rtl sample queue when tuning and during other events (ncurses menu open/close)