v17tx.c File Reference

#include <stdio.h>
#include <inttypes.h>
#include <stdlib.h>
#include <string.h>
#include "floating_fudge.h"
#include "spandsp/telephony.h"
#include "spandsp/logging.h"
#include "spandsp/complex.h"
#include "spandsp/vector_float.h"
#include "spandsp/complex_vector_float.h"
#include "spandsp/async.h"
#include "spandsp/dds.h"
#include "spandsp/power_meter.h"
#include "spandsp/v17tx.h"
#include "v17tx_constellation_maps.h"
#include "v17tx_floating_rrc.h"

Defines
#define	CARRIER_NOMINAL_FREQ   1800.0f
#define	V17_TRAINING_SEG_TEP_A   0
#define	V17_TRAINING_SEG_TEP_B   (V17_TRAINING_SEG_TEP_A + 480)
#define	V17_TRAINING_SEG_1   (V17_TRAINING_SEG_TEP_B + 48)
#define	V17_TRAINING_SEG_2   (V17_TRAINING_SEG_1 + 256)
#define	V17_TRAINING_SEG_3   (V17_TRAINING_SEG_2 + 2976)
#define	V17_TRAINING_SEG_4   (V17_TRAINING_SEG_3 + 64)
#define	V17_TRAINING_END   (V17_TRAINING_SEG_4 + 48)
#define	V17_TRAINING_SHUTDOWN_A   (V17_TRAINING_END + 32)
#define	V17_TRAINING_SHUTDOWN_END   (V17_TRAINING_SHUTDOWN_A + 48)
#define	V17_TRAINING_SHORT_SEG_4   (V17_TRAINING_SEG_2 + 38)
#define	V17_BRIDGE_WORD   0x8880
Functions
int	v17_tx (v17_tx_state_t *s, int16_t amp[], int len)
	Generate a block of V.17 modem audio samples.
void	v17_tx_power (v17_tx_state_t *s, float power)
	Adjust a V.17 modem transmit context's output power.
void	v17_tx_set_get_bit (v17_tx_state_t *s, get_bit_func_t get_bit, void *user_data)
	Change the get_bit function associated with a V.17 modem transmit context.
void	v17_tx_set_modem_status_handler (v17_tx_state_t *s, modem_tx_status_func_t handler, void *user_data)
	Change the modem status report function associated with a V.17 modem transmit context.
int	v17_tx_restart (v17_tx_state_t *s, int bit_rate, int tep, int short_train)
	Reinitialise an existing V.17 modem transmit context.
v17_tx_state_t *	v17_tx_init (v17_tx_state_t *s, int bit_rate, int tep, get_bit_func_t get_bit, void *user_data)
	Initialise a V.17 modem transmit context.
int	v17_tx_free (v17_tx_state_t *s)
	Free a V.17 modem transmit context.

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Detailed Description

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Function Documentation

int v17_tx	(	v17_tx_state_t *	s,
		int16_t	amp[],
		int	len
	)

Generate a block of V.17 modem audio samples.

Generate a block of V.17 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 v17_tx_state_t::baud_phase, v17_tx_state_t::carrier_phase, v17_tx_state_t::carrier_phase_rate, dds_complexf(), dds_complexi(), v17_tx_state_t::gain, complexf_t::im, complexf_t::re, v17_tx_state_t::rrc_filter, v17_tx_state_t::rrc_filter_step, and v17_tx_state_t::training_step.

int v17_tx_free

(

v17_tx_state_t *

s

)

Free a V.17 modem transmit context.

Free a V.17 modem transmit context.

Parameters:

s

The modem context.

Returns:

0 for OK

v17_tx_state_t* v17_tx_init	(	v17_tx_state_t *	s,
		int	rate,
		int	tep,
		get_bit_func_t	get_bit,
		void *	user_data
	)

Initialise a V.17 modem transmit context.

Initialise a V.17 modem transmit context. This must be called before the first use of the context, to initialise its contents.

Parameters:

	s	The modem context.
	rate	The bit rate of the modem. Valid values are 7200, 9600, 12000 and 14400.
	tep	TRUE is the optional TEP tone is to be transmitted.
	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 v17_tx_state_t::carrier_phase_rate, dds_phase_ratef(), v17_tx_state_t::get_bit, v17_tx_state_t::get_bit_user_data, v17_tx_state_t::logging, v17_tx_power(), and v17_tx_restart().

void v17_tx_power	(	v17_tx_state_t *	s,
		float	power
	)

Adjust a V.17 modem transmit context's output power.

Adjust a V.17 modem transmit context's power output.

Parameters:

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

References v17_tx_state_t::gain.

Referenced by v17_tx_init().

int v17_tx_restart	(	v17_tx_state_t *	s,
		int	bit_rate,
		int	tep,
		int	short_train
	)

Reinitialise an existing V.17 modem transmit context.

Reinitialise an existing V.17 modem transmit context, so it may be reused.

Parameters:

	s	The modem context.
	bit_rate	The bit rate of the modem. Valid values are 7200, 9600, 12000 and 14400.
	tep	TRUE is the optional TEP tone is to be transmitted.
	short_train	TRUE if the short training sequence should be used.

Returns:

0 for OK, -1 for parameter error.

References v17_tx_state_t::baud_phase, v17_tx_state_t::bit_rate, v17_tx_state_t::bits_per_symbol, v17_tx_state_t::carrier_phase, v17_tx_state_t::constellation, v17_tx_state_t::constellation_state, v17_tx_state_t::convolution, v17_tx_state_t::current_get_bit, v17_tx_state_t::diff, v17_tx_state_t::in_training, v17_tx_state_t::rrc_filter, v17_tx_state_t::rrc_filter_step, v17_tx_state_t::scramble_reg, v17_tx_state_t::short_train, and v17_tx_state_t::training_step.

Referenced by v17_tx_init().

void v17_tx_set_get_bit	(	v17_tx_state_t *	s,
		get_bit_func_t	get_bit,
		void *	user_data
	)

Change the get_bit function associated with a V.17 modem transmit context.

Change the get_bit function associated with a V.17 modem transmit context.

Parameters:

	s	The modem context.
	get_bit	The callback routine used to get the data to be transmitted.
	user_data	An opaque pointer.

References v17_tx_state_t::current_get_bit, v17_tx_state_t::get_bit, and v17_tx_state_t::get_bit_user_data.

void v17_tx_set_modem_status_handler	(	v17_tx_state_t *	s,
		modem_tx_status_func_t	handler,
		void *	user_data
	)

Change the modem status report function associated with a V.17 modem transmit context.

Change the modem status report function associated with a V.17 modem transmit context.

Parameters:

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

References v17_tx_state_t::status_handler, and v17_tx_state_t::status_user_data.