diff options
Diffstat (limited to 'src/libfm/fm.c')
| -rw-r--r-- | src/libfm/fm.c | 24 |
1 files changed, 4 insertions, 20 deletions
diff --git a/src/libfm/fm.c b/src/libfm/fm.c index 8463dc5..cd13ea1 100644 --- a/src/libfm/fm.c +++ b/src/libfm/fm.c @@ -194,27 +194,11 @@ again: mod->state = MOD_STATE_RAMP_UP; break; } - /* deviation is defined by the frequency value and the offset */ - dev = offset + *frequency++; + /* just count, and add nothing */ + frequency++; power++; length--; - if (fast_math) { - phase += 65536.0 * dev / rate; - if (phase < 0.0) - phase += 65536.0; - else if (phase >= 65536.0) - phase -= 65536.0; - *baseband++ += cos_tab[(uint16_t)phase] * amplitude * ramp_tab[ramp]; - *baseband++ += sin_tab[(uint16_t)phase] * amplitude * ramp_tab[ramp]; - } else { - phase += 2.0 * M_PI * dev / rate; - if (phase < 0.0) - phase += 2.0 * M_PI; - else if (phase >= 2.0 * M_PI) - phase -= 2.0 * M_PI; - *baseband++ += cos(phase) * amplitude * ramp_tab[ramp]; - *baseband++ += sin(phase) * amplitude * ramp_tab[ramp]; - } + baseband += 2; } break; case MOD_STATE_RAMP_UP: @@ -260,7 +244,7 @@ again: mod->ramp = ramp; } -/* init FM demodulator */ +/* init FM demodulator, bandwidth is the 2 * (deviation + modulation) */ int fm_demod_init(fm_demod_t *demod, double samplerate, double offset, double bandwidth) { if (!has_init) { |