41 lines
914 B
C
41 lines
914 B
C
#pragma once
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/* modulation */
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typedef struct {
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/* parameters */
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int dtmf_level; /* in dB */
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int digit_length_ms;
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int digit_pause_ms;
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void *opaque;
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int (*get_digit)(void *opaque);
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/* internal state */
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int omega1,omega2,t1,t2;
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int samples_left;
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int amp;
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} DTMF_mod_state;
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void DTMF_mod_init(DTMF_mod_state *s);
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void DTMF_mod(DTMF_mod_state *s, s16 *samples, unsigned int nb);
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/* demodulation */
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#define DTMF_N 205
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typedef struct {
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/* parameters */
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void *opaque;
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void (*put_digit)(void *opaque, int digit);
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/* internal state */
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s16 buf[DTMF_N];
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int buf_ptr;
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s16 cos_tab[DTMF_N];
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s16 sin_tab[DTMF_N];
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int last_digit;
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int dtmf_coefs[8]; /* coefficient number of the DFT */
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} DTMF_demod_state;
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void DTMF_demod_init(DTMF_demod_state *s);
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void DTMF_demod(DTMF_demod_state *s,
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const s16 *samples, unsigned int nb);
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