v17rx.h File Reference

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Classes
struct	v17_rx_state_t
Defines
#define	_SPANDSP_V17RX_H_
#define	V17_EQUALIZER_PRE_LEN   7
#define	V17_EQUALIZER_POST_LEN   7
#define	V17_EQUALIZER_MASK   63
#define	V17_RX_FILTER_STEPS   27
#define	V17_TRELLIS_STORAGE_DEPTH   16
#define	V17_TRELLIS_LOOKBACK_DEPTH   16
Functions
v17_rx_state_t *	v17_rx_init (v17_rx_state_t *s, int rate, put_bit_func_t put_bit, void *user_data)
	Initialise a V.17 modem receive context.
int	v17_rx_restart (v17_rx_state_t *s, int rate, int short_train)
	Reinitialise an existing V.17 modem receive context.
int	v17_rx_release (v17_rx_state_t *s)
	Release a V.17 modem receive context.
void	v17_rx_set_put_bit (v17_rx_state_t *s, put_bit_func_t put_bit, void *user_data)
	Change the put_bit function associated with a V.17 modem receive context.
void	v17_rx (v17_rx_state_t *s, const int16_t amp[], int len)
	Process a block of received V.17 modem audio samples.
int	v17_rx_equalizer_state (v17_rx_state_t *s, complexf_t **coeffs)
	Get a snapshot of the current equalizer coefficients.
float	v17_rx_carrier_frequency (v17_rx_state_t *s)
float	v17_rx_symbol_timing_correction (v17_rx_state_t *s)
float	v17_rx_signal_power (v17_rx_state_t *s)
void	v17_rx_signal_cutoff (v17_rx_state_t *s, float cutoff)
void	v17_rx_set_qam_report_handler (v17_rx_state_t *s, qam_report_handler_t *handler, void *user_data)
Variables
const complexf_t	v17_14400_constellation [128]
const complexf_t	v17_12000_constellation [64]
const complexf_t	v17_9600_constellation [32]
const complexf_t	v17_7200_constellation [16]

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Detailed Description

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Function Documentation

void v17_rx (  v17_rx_state_t *  s, const int16_t  amp[], int  len )

Process a block of received V.17 modem audio samples. Process a block of received V.17 modem audio samples. Parameters: s  The modem context. amp  The audio sample buffer. len  The number of samples in the buffer.

float v17_rx_carrier_frequency (  v17_rx_state_t *  s  )

Get the current received carrier frequency. Parameters: s  The modem context. Returns: The frequency, in Hertz.

int v17_rx_equalizer_state (  v17_rx_state_t *  s, complexf_t **  coeffs )

Get a snapshot of the current equalizer coefficients. Get a snapshot of the current equalizer coefficients. Parameters: s  The modem context. coeffs  The vector of complex coefficients. Returns: The number of coefficients in the vector.

v17_rx_state_t* v17_rx_init (  v17_rx_state_t *  s, int  rate, put_bit_func_t  put_bit, void *  user_data )

Initialise a V.17 modem receive context. Initialise a V.17 modem receive context. Parameters: s  The modem context. rate  The bit rate of the modem. Valid values are 7200, 9600, 12000 and 14400. put_bit  The callback routine used to put the received data. user_data  An opaque pointer passed to the put_bit routine. Returns: A pointer to the modem context, or NULL if there was a problem.

int v17_rx_release (  v17_rx_state_t *  s  )

Release a V.17 modem receive context. Release a V.17 modem receive context. Parameters: s  The modem context. Returns: 0 for OK

int v17_rx_restart (  v17_rx_state_t *  s, int  rate, int  short_train )

Reinitialise an existing V.17 modem receive context. Reinitialise an existing V.17 modem receive context. Parameters: s  The modem context. rate  The bit rate of the modem. Valid values are 7200, 9600, 12000 and 14400. short_train  TRUE if a short training sequence is expected. Returns: 0 for OK, -1 for bad parameter

void v17_rx_set_put_bit (  v17_rx_state_t *  s, put_bit_func_t  put_bit, void *  user_data )

Change the put_bit function associated with a V.17 modem receive context. Change the put_bit function associated with a V.17 modem receive context. Parameters: s  The modem context. put_bit  The callback routine used to handle received bits. user_data  An opaque pointer.

void v17_rx_set_qam_report_handler (  v17_rx_state_t *  s, qam_report_handler_t *  handler, void *  user_data )

Set a handler routine to process QAM status reports Parameters: s  The modem context. handler  The handler routine. user_data  An opaque pointer passed to the handler routine.

void v17_rx_signal_cutoff (  v17_rx_state_t *  s, float  cutoff )

Set the power level at which the carrier detection will cut in Parameters: s  The modem context. cutoff  The signal cutoff power, in dBm0.

float v17_rx_signal_power (  v17_rx_state_t *  s  )

Get a current received signal power. Parameters: s  The modem context. Returns: The signal power, in dBm0.

float v17_rx_symbol_timing_correction (  v17_rx_state_t *  s  )

Get the current symbol timing correction since startup. Parameters: s  The modem context. Returns: The correction.

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