v17tx.c File Reference

#include <stdio.h>
#include <inttypes.h>
#include <stdlib.h>
#include <string.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"

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
#define	PULSESHAPER_GAIN   (9.9888356312f/10.0f)
#define	PULSESHAPER_COEFF_SETS   10
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.
int	v17_tx_restart (v17_tx_state_t *s, int 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 rate, int tep, get_bit_func_t get_bit, void *user_data)
	Initialise a V.17 modem transmit context.
int	v17_tx_release (v17_tx_state_t *s)
	Release a V.17 modem transmit context.
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

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.

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.

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

int v17_tx_release (  v17_tx_state_t *  s  )

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

int v17_tx_restart (  v17_tx_state_t *  s, int  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. 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.

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.

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Variable Documentation

const complexf_t v17_7200_constellation[16]

Initial value: { { 6, -6}, {-2, 6}, { 6, 2}, {-6, -6}, {-6, 6}, { 2, -6}, {-6, -2}, { 6, 6}, {-2, 2}, { 6, -2}, {-2, -6}, { 2, 2}, { 2, -2}, {-6, 2}, { 2, 6}, {-2, -2} }

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