25 lines
1.1 KiB
C
25 lines
1.1 KiB
C
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typedef struct fm_mod {
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double samplerate; /* sample rate of in and out */
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double offset; /* offset to calculated center frequency */
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double amplitude; /* how much amplitude to add to the buff */
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double phase; /* current phase of FM (used to shift and modulate ) */
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double *sin_tab; /* sine/cosine table for modulation */
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} fm_mod_t;
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void fm_mod_init(fm_mod_t *mod, double samplerate, double offset, double amplitude);
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void fm_modulate(fm_mod_t *mod, sample_t *samples, int num, float *buff);
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typedef struct fm_demod {
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double samplerate; /* sample rate of in and out */
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double phase; /* current rotation phase (used to shift) */
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double rot; /* rotation step per sample to shift rx frequency (used to shift) */
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double last_phase; /* last phase of FM (used to demodulate) */
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iir_filter_t lp[2]; /* filters received IQ signal */
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double *sin_tab; /* sine/cosine table rotation */
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} fm_demod_t;
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void fm_demod_init(fm_demod_t *demod, double samplerate, double offset, double bandwidth);
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void fm_demodulate(fm_demod_t *demod, sample_t *samples, int num, float *buff);
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