diff options
| -rw-r--r-- | util/spkmodem_decode/spkmodem-decode.c | 71 |
1 files changed, 44 insertions, 27 deletions
diff --git a/util/spkmodem_decode/spkmodem-decode.c b/util/spkmodem_decode/spkmodem-decode.c index ff94e90e..aacc6463 100644 --- a/util/spkmodem_decode/spkmodem-decode.c +++ b/util/spkmodem_decode/spkmodem-decode.c @@ -220,7 +220,9 @@ static void collect_separator_tone(struct decoder_state *st); static int valid_signal(struct decoder_state *st); static void decode_pulse(struct decoder_state *st); static void auto_detect_tone(struct decoder_state *st); +static int silent_signal(struct decoder_state *st); static signed short read_sample(struct decoder_state *st); +static void select_low_tone(struct decoder_state *st); static int set_ascii_bit(struct decoder_state *st); static void print_char(struct decoder_state *st); static void print_stats(struct decoder_state *st); @@ -458,38 +460,13 @@ decode_pulse(struct decoder_state *st) static void auto_detect_tone(struct decoder_state *st) { - int f; - if (st->learn_samples >= LEARN_SAMPLES) return; - /* - * Ignore silence / near silence. - * Both FIR windows will be near zero when no signal exists. - */ - if (st->freq_data <= 2 && st->freq_separator <= 2) { - st->learn_samples++; + if (silent_signal(st)) return; - } - - /* - * Choose the lowest active tone. - * Separator frames carry tone in the separator window, - * data frames carry tone in the data window. - */ - f = st->freq_data; - - if (f <= 0 || (st->freq_separator > 0 && - st->freq_separator < f)) - f = st->freq_separator; - if (f > 0) { - if (f < st->freq_min) - st->freq_min = f; - - if (f > st->freq_max) - st->freq_max = f; - } + select_low_tone(st); st->learn_samples++; @@ -503,6 +480,46 @@ auto_detect_tone(struct decoder_state *st) } } +/* + * Ignore silence / near silence. + * Both FIR windows will be near zero when no signal exists. + */ +static int +silent_signal(struct decoder_state *st) +{ + if (st->freq_data > 2 || st->freq_separator > 2) + return 0; + + st->learn_samples++; + return 1; +} + +/* + * Choose the lowest active tone. + * Separator frames carry tone in the separator window, + * data frames carry tone in the data window. + */ +static void +select_low_tone(struct decoder_state *st) +{ + int f; + + f = st->freq_data; + + if (f <= 0 || (st->freq_separator > 0 && + st->freq_separator < f)) + f = st->freq_separator; + + if (f <= 0) + return; + + if (f < st->freq_min) + st->freq_min = f; + + if (f > st->freq_max) + st->freq_max = f; +} + static signed short read_sample(struct decoder_state *st) { |