t31.c File Reference

#include <inttypes.h>
#include <stdlib.h>
#include <stdio.h>
#include <fcntl.h>
#include <time.h>
#include <memory.h>
#include <string.h>
#include <ctype.h>
#include <assert.h>
#include <tiffio.h>
#include "spandsp/telephony.h"
#include "spandsp/logging.h"
#include "spandsp/bit_operations.h"
#include "spandsp/dc_restore.h"
#include "spandsp/queue.h"
#include "spandsp/power_meter.h"
#include "spandsp/complex.h"
#include "spandsp/tone_generate.h"
#include "spandsp/async.h"
#include "spandsp/hdlc.h"
#include "spandsp/silence_gen.h"
#include "spandsp/fsk.h"
#include "spandsp/v29rx.h"
#include "spandsp/v29tx.h"
#include "spandsp/v27ter_rx.h"
#include "spandsp/v27ter_tx.h"
#include "spandsp/v17rx.h"
#include "spandsp/v17tx.h"
#include "spandsp/t4.h"
#include "spandsp/t30.h"
#include "spandsp/t38_core.h"
#include "spandsp/at_interpreter.h"
#include "spandsp/t31.h"

Defines
#define	_GNU_SOURCE
#define	MS_PER_TX_CHUNK   30
#define	INDICATOR_TX_COUNT   3
#define	DATA_TX_COUNT   1
#define	DATA_END_TX_COUNT   1
#define	DEFAULT_DTE_TIMEOUT   5
#define	ETX   0x03
#define	DLE   0x10
#define	SUB   0x1A
Typedefs
typedef const char *(*)	at_cmd_service_t (t31_state_t *s, const char *cmd)
Enumerations
enum	{   T31_FLUSH, T31_SILENCE_TX, T31_SILENCE_RX, T31_CED_TONE,   T31_CNG_TONE, T31_NOCNG_TONE, T31_V21_TX, T31_V17_TX,   T31_V27TER_TX, T31_V29_TX, T31_V21_RX, T31_V17_RX,   T31_V27TER_RX, T31_V29_RX }
enum	{   T38_TIMED_STEP_NONE = 0, T38_TIMED_STEP_NON_ECM_MODEM, T38_TIMED_STEP_NON_ECM_MODEM_2, T38_TIMED_STEP_NON_ECM_MODEM_3,   T38_TIMED_STEP_HDLC_MODEM, T38_TIMED_STEP_HDLC_MODEM_2, T38_TIMED_STEP_HDLC_MODEM_3, T38_TIMED_STEP_HDLC_MODEM_4,   T38_TIMED_STEP_PAUSE }
Functions
int	t31_t38_send_timeout (t31_state_t *s, int samples)
void	t31_call_event (t31_state_t *s, int event)
int	t31_at_rx (t31_state_t *s, const char *t, int len)
int	t31_rx (t31_state_t *s, int16_t amp[], int len)
	Process a block of received T.31 modem audio samples.
int	t31_tx (t31_state_t *s, int16_t amp[], int max_len)
	Generate a block of T.31 modem audio samples.
void	t31_set_transmit_on_idle (t31_state_t *s, int transmit_on_idle)
	Select whether silent audio will be sent when transmit is idle.
t31_state_t *	t31_init (t31_state_t *s, at_tx_handler_t *at_tx_handler, void *at_tx_user_data, t31_modem_control_handler_t *modem_control_handler, void *modem_control_user_data, t38_tx_packet_handler_t *tx_t38_packet_handler, void *tx_t38_packet_user_data)
	Initialise a T.31 context.
int	t31_release (t31_state_t *s)
	Release a T.31 context.

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Detailed Description

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Function Documentation

t31_state_t* t31_init	(	t31_state_t *	s,
		at_tx_handler_t *	at_tx_handler,
		void *	at_tx_user_data,
		t31_modem_control_handler_t *	modem_control_handler,
		void *	modem_control_user_data,
		t38_tx_packet_handler_t *	tx_t38_packet_handler,
		void *	tx_t38_packet_user_data
	)

Initialise a T.31 context.

Initialise a T.31 context. This must be called before the first use of the context, to initialise its contents.

Parameters:

	s	The T.31 context.
	at_tx_handler	A callback routine to handle AT interpreter channel output.
	at_tx_user_data	An opaque pointer passed in called to at_tx_handler.
	modem_control_handler	A callback routine to handle control of the modem (off-hook, etc).
	modem_control_user_data	An opaque pointer passed in called to modem_control_handler.
	tx_t38_packet_handler	???
	tx_t38_packet_user_data	???

Returns:

A pointer to the T.31 context.

int t31_release

(

t31_state_t *

s

)

Release a T.31 context.

Release a T.31 context.

Parameters:

s

The T.31 context.

Returns:

0 for OK

int t31_rx	(	t31_state_t *	s,
		int16_t	amp[],
		int	len
	)

Process a block of received T.31 modem audio samples.

Process a block of received T.31 modem audio samples.

Parameters:

	s	The T.31 modem context.
	amp	The audio sample buffer.
	len	The number of samples in the buffer.

Returns:

The number of samples unprocessed.

void t31_set_transmit_on_idle	(	t31_state_t *	s,
		int	transmit_on_idle
	)

Select whether silent audio will be sent when transmit is idle.

Select whether silent audio will be sent when transmit is idle.

Parameters:

	s	The T.31 modem context.
	transmit_on_idle	TRUE if silent audio should be output when the transmitter is idle. FALSE to transmit zero length audio when the transmitter is idle. The default behaviour is FALSE.

int t31_tx	(	t31_state_t *	s,
		int16_t	amp[],
		int	max_len
	)

Generate a block of T.31 modem audio samples.

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.

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