diff options
| author | Kyle Keen <keenerd@gmail.com> | 2012-09-04 22:01:17 -0400 |
|---|---|---|
| committer | Steve Markgraf <steve@steve-m.de> | 2012-09-10 18:51:07 +0200 |
| commit | 1533422f982b66b340da26357608cb479b3ff7dd (patch) | |
| tree | 9b4470f7a878862db6eb9072c9c57153c13c6da2 /src/rtl_fm.c | |
| parent | a8e7c7b21ea7fb52b6d2ac9d56be08d6638d751b (diff) | |
rtl_fm: half the oversample bugs
Signed-off-by: Steve Markgraf <steve@steve-m.de>
Diffstat (limited to 'src/rtl_fm.c')
| -rw-r--r-- | src/rtl_fm.c | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/src/rtl_fm.c b/src/rtl_fm.c index c1162dc..df7d768 100644 --- a/src/rtl_fm.c +++ b/src/rtl_fm.c @@ -86,7 +86,7 @@ struct fm_state int signal_len; FILE *file; int edge; - uint32_t freqs[32]; + uint32_t freqs[100]; int freq_len; int freq_now; uint32_t sample_rate; @@ -236,8 +236,9 @@ int low_pass_simple(int16_t *signal2, int len, int step) for(i2=0; i2<step; i2++) { sum += (int)signal2[i + i2]; } - signal2[i] = (int16_t)(sum / step); + signal2[i/step] = (int16_t)(sum / step); } + signal2[i/step + 1] = signal2[i/step]; return len / step; } @@ -346,7 +347,7 @@ int post_squelch(struct fm_state *fm) return 0;} /* weak signal, kill it entirely */ for (i=0; i<len; i++) { - fm->signal2[i/2] = 0; + fm->signal2[i] = 0; } return 0; } @@ -396,7 +397,7 @@ void full_demod(unsigned char *buf, uint32_t len, struct fm_state *fm) fm_demod(fm); sr = post_squelch(fm); if (fm->post_downsample > 1) { - fm->signal_len = low_pass_simple(fm->signal2, fm->signal_len, fm->post_downsample);} + fm->signal_len = low_pass_simple(fm->signal2, fm->signal_len/2, fm->post_downsample)*2;} /* ignore under runs for now */ fwrite(fm->signal2, 2, fm->signal_len/2, fm->file); if (fm->freq_len > 1 && !sr && fm->squelch_hits > CONSEQ_SQUELCH) { @@ -463,7 +464,7 @@ int main(int argc, char **argv) fm.edge = 0; fm.fir_enable = 0; fm.prev_index = -1; - fm.post_downsample = 1; + fm.post_downsample = 1; // once this works, default = 4 fm.custom_atan = 0; sem_init(&data_ready, 0, 0); @@ -505,7 +506,7 @@ int main(int argc, char **argv) break; } } - /* double sample_rate to limit to Δθ to ±π */ + /* quadruple sample_rate to limit to Δθ to ±π/2 */ fm.sample_rate *= fm.post_downsample; if (argc <= optind) { |