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Rewrite spkmodem to use PIT for timing. Double the speed.

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This commit is contained in:
Vladimir 'phcoder' Serbinenko 2013-01-17 20:06:52 +01:00
parent 7d462559da
commit 17334a6b6a
4 changed files with 61 additions and 26 deletions
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26
util/spkmodem-recv.c
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@ -5,19 +5,13 @@
/* Compilation: gcc -o spkmodem-recv spkmodem-recv */
/* Usage: parecord --channels=1 --rate=48000 --format=s16le | ./spkmodem-recv */
#define RATE 48000
#define SAMPLES_PER_TRAME 480
#define AMPLITUDE_THRESHOLD 100000
#define FREQ_SEP_MIN 15
#define FREQ_SEP_NOM 20
#define FREQ_SEP_MAX 25
#define FREQ_DATA_MIN 10
#define FREQ_DATA_THRESHOLD 60
#define FREQ_DATA_MAX 120
#define AMPLITUDE_SAMPLES 2 * SAMPLES_PER_TRAME
#define THRESHOLD 1000
#define SAMPLES_PER_TRAME 240
#define FREQ_SEP_MIN 6
#define FREQ_SEP_MAX 15
#define FREQ_DATA_MIN 15
#define FREQ_DATA_THRESHOLD 25
#define FREQ_DATA_MAX 60
#define THRESHOLD 500
#define DEBUG 0
@ -67,14 +61,14 @@ main ()
c = 0;
lp = 0;
}
if (f2 > 12 && f2 < 25
&& f1 > 5 && f1 < 120)
if (f2 > FREQ_SEP_MIN && f2 < FREQ_SEP_MAX
&& f1 > FREQ_DATA_MIN && f1 < FREQ_DATA_MAX)
{
#if DEBUG
printf ("%d %d %d @%d\n", f1, f2, FREQ_DATA_THRESHOLD,
ftell (stdin) - sizeof (trame));
#endif
if (f1 < 60)
if (f1 < FREQ_DATA_THRESHOLD)
c |= (1 << bitn);
bitn--;
if (bitn < 0)