fsk.h File Reference

Go to the source code of this file.

Classes

struct  fsk_spec_t

Defines

#define _SPANDSP_FSK_H_
#define FSK_MAX_WINDOW_LEN   128

Typedefs

typedef struct fsk_tx_state_s fsk_tx_state_t
typedef struct fsk_rx_state_s fsk_rx_state_t

Enumerations

enum  {
  FSK_V21CH1 = 0, FSK_V21CH2, FSK_V23CH1, FSK_V23CH2,
  FSK_BELL103CH1, FSK_BELL103CH2, FSK_BELL202, FSK_WEITBRECHT,
  FSK_WEITBRECHT50
}

Functions

fsk_tx_state_tfsk_tx_init (fsk_tx_state_t *s, const fsk_spec_t *spec, get_bit_func_t get_bit, void *user_data)
 Initialise an FSK modem transmit context.
int fsk_tx_release (fsk_tx_state_t *s)
int fsk_tx_free (fsk_tx_state_t *s)
void fsk_tx_power (fsk_tx_state_t *s, float power)
 Adjust an FSK modem transmit context's power output.
void fsk_tx_set_get_bit (fsk_tx_state_t *s, get_bit_func_t get_bit, void *user_data)
void fsk_tx_set_modem_status_handler (fsk_tx_state_t *s, modem_tx_status_func_t handler, void *user_data)
 Change the modem status report function associated with an FSK modem transmit context.
int fsk_tx (fsk_tx_state_t *s, int16_t amp[], int len)
 Generate a block of FSK modem audio samples.
float fsk_rx_signal_power (fsk_rx_state_t *s)
void fsk_rx_signal_cutoff (fsk_rx_state_t *s, float cutoff)
 Adjust an FSK modem receive context's carrier detect power threshold.
fsk_rx_state_tfsk_rx_init (fsk_rx_state_t *s, const fsk_spec_t *spec, int framing_mode, put_bit_func_t put_bit, void *user_data)
 Initialise an FSK modem receive context.
int fsk_rx_release (fsk_rx_state_t *s)
int fsk_rx_free (fsk_rx_state_t *s)
int fsk_rx (fsk_rx_state_t *s, const int16_t *amp, int len)
 Process a block of received FSK modem audio samples.
int fsk_rx_fillin (fsk_rx_state_t *s, int len)
 Fake processing of a missing block of received FSK modem audio samples.
void fsk_rx_set_put_bit (fsk_rx_state_t *s, put_bit_func_t put_bit, void *user_data)
void fsk_rx_set_modem_status_handler (fsk_rx_state_t *s, modem_rx_status_func_t handler, void *user_data)
 Change the modem status report function associated with an FSK modem receive context.

Variables

SPAN_DECLARE_DATA const fsk_spec_t preset_fsk_specs []


Detailed Description


Typedef Documentation

FSK modem receive descriptor. This defines the state of a single working instance of an FSK modem receiver.

FSK modem transmit descriptor. This defines the state of a single working instance of an FSK modem transmitter.


Function Documentation

int fsk_rx ( fsk_rx_state_t s,
const int16_t *  amp,
int  len 
)

Process a block of received FSK modem audio samples.

Process a block of received FSK modem audio samples.

Parameters:
s The modem context.
amp The audio sample buffer.
len The number of samples in the buffer.
Returns:
The number of samples unprocessed.

References dds_complexi(), complexi_t::im, power_meter_update(), complexi_t::re, SIG_STATUS_CARRIER_DOWN, and SIG_STATUS_CARRIER_UP.

Referenced by adsi_rx(), modem_connect_tones_rx(), v18_rx(), and v8_rx().

int fsk_rx_fillin ( fsk_rx_state_t s,
int  len 
)

Fake processing of a missing block of received FSK modem audio samples.

Fake processing of a missing block of received FSK modem audio samples (e.g due to packet loss).

Parameters:
s The modem context.
len The number of samples to fake.
Returns:
The number of samples unprocessed.

Referenced by fax_rx_fillin(), and t31_rx_fillin().

fsk_rx_state_t* fsk_rx_init ( fsk_rx_state_t s,
const fsk_spec_t spec,
int  framing_mode,
put_bit_func_t  put_bit,
void *  user_data 
)

Initialise an FSK modem receive context.

Initialise an FSK modem receive context.

Parameters:
s The modem context.
spec The specification of the modem tones and rate.
framing_mode 0 for fully asynchronous mode. 1 for synchronous mode. >1 for this many bits per asynchronous character frame.
put_bit The callback routine used to put the received data.
user_data An opaque pointer.
Returns:
A pointer to the modem context, or NULL if there was a problem.

References dds_phase_rate(), fsk_rx_signal_cutoff(), and power_meter_init().

Referenced by adsi_rx_init(), modem_connect_tones_rx_init(), and v18_init().

void fsk_rx_set_modem_status_handler ( fsk_rx_state_t s,
modem_rx_status_func_t  handler,
void *  user_data 
)

Change the modem status report function associated with an FSK modem receive context.

Change the modem status report function associated with an FSK modem receive context.

Parameters:
s The modem context.
handler The callback routine used to report modem status changes.
user_data An opaque pointer.

void fsk_rx_signal_cutoff ( fsk_rx_state_t s,
float  cutoff 
)

Adjust an FSK modem receive context's carrier detect power threshold.

Adjust an FSK modem receive context's carrier detect power threshold.

Parameters:
s The modem context.
cutoff The power level, in dBm0

References power_meter_level_dbm0().

Referenced by fsk_rx_init(), and modem_connect_tones_rx_init().

float fsk_rx_signal_power ( fsk_rx_state_t s  ) 

Get the current received signal power.

Parameters:
s The modem context.
Returns:
The signal power, in dBm0.

References power_meter_current_dbm0().

int fsk_tx ( fsk_tx_state_t s,
int16_t  amp[],
int  len 
)

Generate a block of FSK modem audio samples.

Generate a block of FSK modem audio samples.

Parameters:
s The modem context.
amp The audio sample buffer.
len The number of samples to be generated.
Returns:
The number of samples actually generated.

References dds_mod(), SIG_STATUS_END_OF_DATA, and SIG_STATUS_SHUTDOWN_COMPLETE.

Referenced by adsi_tx(), and v8_tx().

fsk_tx_state_t* fsk_tx_init ( fsk_tx_state_t s,
const fsk_spec_t spec,
get_bit_func_t  get_bit,
void *  user_data 
)

Initialise an FSK modem transmit context.

Initialise an FSK modem transmit context.

Parameters:
s The modem context.
spec The specification of the modem tones and rate.
get_bit The callback routine used to get the data to be transmitted.
user_data An opaque pointer.
Returns:
A pointer to the modem context, or NULL if there was a problem.

References dds_phase_rate(), and dds_scaling_dbm0().

Referenced by v18_init(), and v8_rx().

void fsk_tx_power ( fsk_tx_state_t s,
float  power 
)

Adjust an FSK modem transmit context's power output.

Adjust an FSK modem transmit context's power output.

Parameters:
s The modem context.
power The power level, in dBm0

References dds_scaling_dbm0().

void fsk_tx_set_modem_status_handler ( fsk_tx_state_t s,
modem_tx_status_func_t  handler,
void *  user_data 
)

Change the modem status report function associated with an FSK modem transmit context.

Change the modem status report function associated with an FSK modem transmit context.

Parameters:
s The modem context.
handler The callback routine used to report modem status changes.
user_data An opaque pointer.


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