v27ter_rx.h File Reference

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Typedefs
typedef struct v27ter_rx_state_s	v27ter_rx_state_t

Functions
v27ter_rx_state_t *	v27ter_rx_init (v27ter_rx_state_t *s, int bit_rate, put_bit_func_t put_bit, void *user_data)
	Initialise a V.27ter modem receive context.
int	v27ter_rx_restart (v27ter_rx_state_t *s, int bit_rate, int old_train)
	Reinitialise an existing V.27ter modem receive context.
int	v27ter_rx_release (v27ter_rx_state_t *s)
	Release a V.27ter modem receive context.
int	v27ter_rx_free (v27ter_rx_state_t *s)
	Free a V.27ter modem receive context.
logging_state_t *	v27ter_rx_get_logging_state (v27ter_rx_state_t *s)
	Get the logging context associated with a V.27ter modem receive context.
void	v27ter_rx_set_put_bit (v27ter_rx_state_t *s, put_bit_func_t put_bit, void *user_data)
	Change the put_bit function associated with a V.27ter modem receive context.
void	v27ter_rx_set_modem_status_handler (v27ter_rx_state_t *s, modem_status_func_t handler, void *user_data)
	Change the modem status report function associated with a V.27ter modem receive context.
	SPAN_DECLARE_NONSTD (int) v27ter_rx(v27ter_rx_state_t *s
	Process a block of received V.27ter modem audio samples.
int	v27ter_rx_equalizer_state (v27ter_rx_state_t *s, complexf_t **coeffs)
	Get a snapshot of the current equalizer coefficients.
float	v27ter_rx_carrier_frequency (v27ter_rx_state_t *s)
float	v27ter_rx_symbol_timing_correction (v27ter_rx_state_t *s)
float	v27ter_rx_signal_power (v27ter_rx_state_t *s)
void	v27ter_rx_signal_cutoff (v27ter_rx_state_t *s, float cutoff)
void	v27ter_rx_set_qam_report_handler (v27ter_rx_state_t *s, qam_report_handler_t handler, void *user_data)

Variables
const int16_t	amp []
const int16_t int	len

Typedef Documentation

v27ter_rx_state_t

typedef struct v27ter_rx_state_s v27ter_rx_state_t

V.27ter modem receive side descriptor. This defines the working state for a single instance of a V.27ter modem receiver.

Function Documentation

SPAN_DECLARE_NONSTD()

SPAN_DECLARE_NONSTD

(

int

)

Process a block of received V.27ter modem audio samples.

Get the next bit of a transmitted serial bit stream.

Fake processing of a missing block of received V.27ter modem audio samples.

Process a block of received V.27ter 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.

Fake processing of a missing block of received V.27ter 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.

Apply T.30 receive processing to a block of audio samples.

Process a block of received V.8 audio samples.

Fake processing of a missing block of received V.29 modem audio samples.

Fake processing of a missing block of received V.27ter modem audio samples.

Generate a block of V.22bis modem audio samples.

Fake processing of a missing block of received V.22bis modem audio samples.

Process a block of received V.18 audio samples.

Fake processing of a missing block of received V.17 modem audio samples.

Generate a block of FAX audio samples.

Apply fake received audio processing.

Process a received T.38 IFP packet from a reliable stream (e.g. TCP).

Generate a block of T.31 modem audio samples.

Fake processing of a missing block of received T.31 modem audio samples.

Dummy receive fillin callback.

Dummy receive callback.

Process a block of samples through an instance of the modem connect tones detector.

Get the next sequence of bytes for transmission.

Get the next byte for transmission.

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

Process a block of received FSK modem audio samples.

Apply T.30 transmit processing to generate a block of audio samples.

Apply fake T.30 receive processing.

Get the next bit of a transmitted serial bit stream.

Parameters

user_data

An opaque point which must point to a transmitter context.

Returns

the next bit, or PUTBIT_END_OF_DATA to indicate the data stream has ended.

Apply fake T.30 receive processing when a block of audio samples is missing (e.g due to packet loss).

Parameters

s	The FAX context.
len	The number of samples to fake.

Returns

The number of samples unprocessed. This should only be non-zero if the software has reached the end of the FAX call.

Apply T.30 transmit processing to generate a block of audio samples.

Parameters

s	The FAX context.
amp	The audio sample buffer.
max_len	The number of samples to be generated.

Returns

The number of samples actually generated. This will be zero when there is nothing to send.

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.

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.

Parameters

s	A pointer to an HDLC transmitter context.

Returns

The next byte for transmission.

Parameters

s	A pointer to an HDLC transmitter context.
buf	The buffer for the data.
max_len	The number of bytes to get.

Returns

The number of bytes actually got.

Parameters

s	The context.
amp	An array of signal samples.
len	The number of samples in the array.

Returns

The number of unprocessed samples.

A dummy routine to use as a receive callback, when we aren't really trying to process what is received. It just absorbs and ignores the data.

Parameters

user_data	The context.
amp	The signal.buffer
len	The length of the signal buffer

Returns

0.

A dummy routine to use as a receive fillin callback, when we aren't really trying to process what is received. It just absorbs and ignores the request.

Parameters

user_data	The context.
len	The length of the signal buffer

Returns

0.

Fake processing of a missing block of received T.31 modem audio samples (e.g due to packet loss).

Parameters

s	The T.31 modem context.
len	The number of samples to fake.

Returns

The number of samples unprocessed.

Generate a block of T.31 modem audio samples.

Parameters

s	The T.31 modem context.
amp	The audio sample buffer.
max_len	The number of samples to be generated.

Returns

The number of samples actually generated.

Parameters

s	The T.38 context.
buf	The packet contents.
len	The length of the packet contents.
seq_no	The packet sequence number, used for logging purposes.

Returns

The length of the packet processed, or -1 if there is an error in the packet, or too few bytes of data to complete it.

Apply fake processing when a block of audio samples is missing (e.g due to packet loss).

Parameters

s	The T.38 context.
len	The number of samples to fake.

Returns

The number of samples unprocessed. This should only be non-zero if the software has reached the end of the FAX call.

Generate a block of FAX audio samples.

Parameters

s	The T.38 context.
amp	The audio sample buffer.
max_len	The number of samples to be generated.

Returns

The number of samples actually generated.

Fake processing of a missing block of received V.17 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.

Process a block of received V.18 audio samples.

Parameters

s	The V.18 context.
amp	The audio sample buffer.
len	The number of samples in the buffer.

Fake processing of a missing block of received V.22bis 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.

Generate a block of V.22bis 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.

Fake processing of a missing block of received V.27ter 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.

Fake processing of a missing block of received V.29 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.

Process a block of received V.8 audio samples.

Parameters

s	The V.8 context.
amp	The audio sample buffer.
len	The number of samples in the buffer.

Get the next bit of a transmitted serial bit stream.

Apply T.30 transmit processing to generate a block of audio samples.

Apply fake T.30 receive processing.

Apply T.30 receive processing to a block of audio samples.

Parameters

s	The FAX context.
amp	The audio sample buffer.
len	The number of samples in the buffer.

Returns

The number of samples unprocessed. This should only be non-zero if the software has reached the end of the FAX call.

Apply fake T.30 receive processing when a block of audio samples is missing (e.g due to packet loss).

Parameters

s	The FAX context.
len	The number of samples to fake.

Returns

The number of samples unprocessed. This should only be non-zero if the software has reached the end of the FAX call.

Apply T.30 transmit processing to generate a block of audio samples.

Parameters

s	The FAX context.
amp	The audio sample buffer.
max_len	The number of samples to be generated.

Returns

The number of samples actually generated. This will be zero when there is nothing to send.

v27ter_rx_carrier_frequency()

float v27ter_rx_carrier_frequency

(

v27ter_rx_state_t *

s

)

Get the current received carrier frequency.

Parameters

s	The modem context.

Returns

The frequency, in Hertz.

References v27ter_rx_state_s::carrier_phase_rate, and dds_frequencyf().

v27ter_rx_equalizer_state()

int v27ter_rx_equalizer_state	(	v27ter_rx_state_t *	s,
		complexf_t **	coeffs )

Get a snapshot of the current equalizer coefficients.

Get a snapshot of the current equalizer coefficients.

Parameters

coeffs

The vector of complex coefficients.

Returns

The number of coefficients in the vector.

References v27ter_rx_state_s::eq_coeff.

v27ter_rx_free()

int v27ter_rx_free

(

v27ter_rx_state_t *

s

)

Free a V.27ter modem receive context.

Free a V.27ter modem receive context.

Parameters

s	The modem context.

Returns

0 for OK

v27ter_rx_get_logging_state()

logging_state_t * v27ter_rx_get_logging_state

(

v27ter_rx_state_t *

s

)

Get the logging context associated with a V.27ter modem receive context.

Get the logging context associated with a V.27ter modem receive context.

Parameters

s	The modem context.

Returns

A pointer to the logging context

References v27ter_rx_state_s::logging.

v27ter_rx_init()

v27ter_rx_state_t * v27ter_rx_init	(	v27ter_rx_state_t *	s,
		int	bit_rate,
		put_bit_func_t	put_bit,
		void *	user_data )

Initialise a V.27ter modem receive context.

Initialise a V.27ter modem receive context.

Parameters

s	The modem context.
bit_rate	The bit rate of the modem. Valid values are 2400 and 4800.
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.

References v27ter_rx_state_s::logging, v27ter_rx_state_s::put_bit, v27ter_rx_state_s::put_bit_user_data, v27ter_rx_restart(), and v27ter_rx_signal_cutoff().

v27ter_rx_release()

int v27ter_rx_release

(

v27ter_rx_state_t *

s

)

Release a V.27ter modem receive context.

Release a V.27ter modem receive context.

Parameters

s	The modem context.

Returns

0 for OK

v27ter_rx_restart()

int v27ter_rx_restart	(	v27ter_rx_state_t *	s,
		int	bit_rate,
		int	old_train )

Reinitialise an existing V.27ter modem receive context.

Reinitialise an existing V.27ter modem receive context.

Parameters

s	The modem context.
bit_rate	The bit rate of the modem. Valid values are 2400 and 4800.
old_train	TRUE if a previous trained values are to be reused.

Returns

0 for OK, -1 for bad parameter

References v27ter_rx_state_s::agc_scaling, v27ter_rx_state_s::agc_scaling_save, v27ter_rx_state_s::baud_half, v27ter_rx_state_s::bit_rate, v27ter_rx_state_s::carrier_drop_pending, CARRIER_NOMINAL_FREQ, v27ter_rx_state_s::carrier_phase, v27ter_rx_state_s::carrier_phase_rate, v27ter_rx_state_s::carrier_phase_rate_save, v27ter_rx_state_s::carrier_track_i, v27ter_rx_state_s::carrier_track_p, v27ter_rx_state_s::constellation_state, v27ter_rx_state_s::diff_angles, v27ter_rx_state_s::eq_skip, v27ter_rx_state_s::gardner_integrate, v27ter_rx_state_s::gardner_step, v27ter_rx_state_s::high_sample, v27ter_rx_state_s::last_sample, v27ter_rx_state_s::logging, v27ter_rx_state_s::low_samples, v27ter_rx_state_s::old_train, v27ter_rx_state_s::power, power_meter_init(), v27ter_rx_state_s::rrc_filter, v27ter_rx_state_s::rrc_filter_step, v27ter_rx_state_s::scramble_reg, v27ter_rx_state_s::scrambler_pattern_count, v27ter_rx_state_s::signal_present, span_log(), v27ter_rx_state_s::total_baud_timing_correction, v27ter_rx_state_s::training_bc, v27ter_rx_state_s::training_count, v27ter_rx_state_s::training_error, and v27ter_rx_state_s::training_stage.

Referenced by v27ter_rx_init().

v27ter_rx_set_modem_status_handler()

void v27ter_rx_set_modem_status_handler	(	v27ter_rx_state_t *	s,
		modem_status_func_t	handler,
		void *	user_data )

Change the modem status report function associated with a V.27ter modem receive context.

Change the modem status report function associated with a V.27ter modem receive context.

Parameters

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

References v27ter_rx_state_s::status_handler, and v27ter_rx_state_s::status_user_data.

v27ter_rx_set_put_bit()

void v27ter_rx_set_put_bit	(	v27ter_rx_state_t *	s,
		put_bit_func_t	put_bit,
		void *	user_data )

Change the put_bit function associated with a V.27ter modem receive context.

Change the put_bit function associated with a V.27ter modem receive context.

Parameters

s	The modem context.
put_bit	The callback routine used to handle received bits.
user_data	An opaque pointer.

References v27ter_rx_state_s::put_bit, and v27ter_rx_state_s::put_bit_user_data.

v27ter_rx_set_qam_report_handler()

void v27ter_rx_set_qam_report_handler	(	v27ter_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.

References v27ter_rx_state_s::qam_report, and v27ter_rx_state_s::qam_user_data.

v27ter_rx_signal_cutoff()

void v27ter_rx_signal_cutoff	(	v27ter_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.

References v27ter_rx_state_s::carrier_off_power, v27ter_rx_state_s::carrier_on_power, and power_meter_level_dbm0().

Referenced by v27ter_rx_init().

v27ter_rx_signal_power()

float v27ter_rx_signal_power

(

v27ter_rx_state_t *

s

)

Get a current received signal power.

Parameters

s	The modem context.

Returns

The signal power, in dBm0.

References v27ter_rx_state_s::power, and power_meter_current_dbm0().

v27ter_rx_symbol_timing_correction()

float v27ter_rx_symbol_timing_correction

(

v27ter_rx_state_t *

s

)

Get the current symbol timing correction since startup.

Parameters

s	The modem context.

Returns

The correction.

References v27ter_rx_state_s::bit_rate, and v27ter_rx_state_s::total_baud_timing_correction.