t38_core.c File Reference

#include <inttypes.h>
#include <stdlib.h>
#include <stdio.h>
#include <fcntl.h>
#include <time.h>
#include <string.h>
#include "floating_fudge.h"
#include <assert.h>
#include <memory.h>
#include <tiffio.h>
#include "spandsp/telephony.h"
#include "spandsp/logging.h"
#include "spandsp/bit_operations.h"
#include "spandsp/t38_core.h"

Defines
#define	ACCEPTABLE_SEQ_NO_OFFSET   2000
Functions
const char *	t38_indicator_to_str (int indicator)
	Convert the code for an indicator to a short text name.
const char *	t38_data_type_to_str (int data_type)
	Convert the code for a type of data to a short text name.
const char *	t38_field_type_to_str (int field_type)
	Convert the code for a type of data field to a short text name.
const char *	t38_cm_profile_to_str (int profile)
	Convert the code for a CM profile code to text description.
const char *	t38_jm_to_str (const uint8_t *data, int len)
	Convert a JM message code to text description.
int	t38_v34rate_to_bps (const uint8_t *data, int len)
	Convert a V34rate message to an actual bit rate.
int	t38_core_rx_ifp_packet (t38_core_state_t *s, const uint8_t *buf, int len, uint16_t seq_no)
	Process a received T.38 IFP packet.
int	t38_core_send_indicator (t38_core_state_t *s, int indicator, int count)
	Send an indicator packet.
int	t38_core_send_data (t38_core_state_t *s, int data_type, int field_type, const uint8_t field[], int field_len, int count)
	Send a data packet.
int	t38_core_send_data_multi_field (t38_core_state_t *s, int data_type, const t38_data_field_t field[], int fields, int count)
	Send a data packet.
void	t38_set_data_rate_management_method (t38_core_state_t *s, int method)
void	t38_set_data_transport_protocol (t38_core_state_t *s, int data_transport_protocol)
void	t38_set_fill_bit_removal (t38_core_state_t *s, int fill_bit_removal)
void	t38_set_mmr_transcoding (t38_core_state_t *s, int mmr_transcoding)
void	t38_set_jbig_transcoding (t38_core_state_t *s, int jbig_transcoding)
void	t38_set_max_buffer_size (t38_core_state_t *s, int max_buffer_size)
void	t38_set_max_datagram_size (t38_core_state_t *s, int max_datagram_size)
void	t38_set_t38_version (t38_core_state_t *s, int t38_version)
void	t38_set_sequence_number_handling (t38_core_state_t *s, int check)
int	t38_get_fastest_image_data_rate (t38_core_state_t *s)
t38_core_state_t *	t38_core_init (t38_core_state_t *s, t38_rx_indicator_handler_t *rx_indicator_handler, t38_rx_data_handler_t *rx_data_handler, t38_rx_missing_handler_t *rx_missing_handler, void *rx_user_data, t38_tx_packet_handler_t *tx_packet_handler, void *tx_packet_user_data)

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Detailed Description

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Function Documentation

const char* t38_cm_profile_to_str

(

int

profile

)

Convert the code for a CM profile code to text description.

Parameters:

profile

The profile code from a CM message.

Returns:

A pointer to a short text description of the profile.

int t38_core_rx_ifp_packet	(	t38_core_state_t *	s,
		const uint8_t *	buf,
		int	len,
		uint16_t	seq_no
	)

Process a received T.38 IFP packet.

Parameters:

	s	The T.38 context.
	buf	The packet contents.
	len	The length of the packet contents.
	seq_no	The packet sequence number.

Returns:

0 for OK, else -1.

References t38_core_state_s::check_sequence_numbers, t38_core_state_s::current_rx_data_type, t38_core_state_s::current_rx_field_type, t38_core_state_s::current_rx_indicator, t38_core_state_s::logging, t38_core_state_s::missing_packets, t38_core_state_s::rx_data_handler, t38_core_state_s::rx_expected_seq_no, t38_core_state_s::rx_indicator_handler, t38_core_state_s::rx_missing_handler, t38_core_state_s::rx_user_data, span_log(), span_log_buf(), span_log_test(), t38_data_type_to_str(), t38_field_type_to_str(), t38_indicator_to_str(), and t38_core_state_s::t38_version.

int t38_core_send_data	(	t38_core_state_t *	s,
		int	data_type,
		int	field_type,
		const uint8_t	field[],
		int	field_len,
		int	count
	)

Send a data packet.

Parameters:

	s	The T.38 context.
	data_type	The packet's data type.
	field_type	The packet's field type.
	field	The message data content for the packet.
	field_len	The length of the message data, in bytes.
	count	The number of copies of the packet to send.

Returns:

???

References t38_data_field_t::field, t38_data_field_t::field_len, t38_data_field_t::field_type, t38_core_state_s::logging, span_log(), t38_core_state_s::tx_packet_handler, t38_core_state_s::tx_packet_user_data, and t38_core_state_s::tx_seq_no.

int t38_core_send_data_multi_field	(	t38_core_state_t *	s,
		int	data_type,
		const t38_data_field_t	field[],
		int	fields,
		int	count
	)

Send a data packet.

Parameters:

	s	The T.38 context.
	data_type	The packet's data type.
	field	The list of fields.
	fields	The number of fields in the list.
	count	The number of copies of the packet to send.

Returns:

???

References t38_core_state_s::logging, span_log(), t38_core_state_s::tx_packet_handler, t38_core_state_s::tx_packet_user_data, and t38_core_state_s::tx_seq_no.

int t38_core_send_indicator	(	t38_core_state_t *	s,
		int	indicator,
		int	count
	)

Send an indicator packet.

Parameters:

	s	The T.38 context.
	indicator	The indicator to send.
	count	The number of copies of the packet to send.

Returns:

???

References t38_core_state_s::current_tx_indicator, t38_core_state_s::logging, span_log(), t38_indicator_to_str(), t38_core_state_s::tx_packet_handler, t38_core_state_s::tx_packet_user_data, and t38_core_state_s::tx_seq_no.

const char* t38_data_type_to_str

(

int

data_type

)

Convert the code for a type of data to a short text name.

Parameters:

data_type

The data type.

Returns:

A pointer to a short text name for the data type.

Referenced by t38_core_rx_ifp_packet().

const char* t38_field_type_to_str

(

int

field_type

)

Convert the code for a type of data field to a short text name.

Parameters:

field_type

The field type.

Returns:

A pointer to a short text name for the field type.

Referenced by t38_core_rx_ifp_packet().

const char* t38_indicator_to_str

(

int

indicator

)

Convert the code for an indicator to a short text name.

Parameters:

indicator

The type of indicator.

Returns:

A pointer to a short text name for the indicator.

Referenced by t38_core_rx_ifp_packet(), and t38_core_send_indicator().

const char* t38_jm_to_str	(	const uint8_t *	data,
		int	len
	)

Convert a JM message code to text description.

Parameters:

	data	The data field of the message.
	len	The length of the data field.

Returns:

A pointer to a short text description of the profile.

void t38_set_data_rate_management_method	(	t38_core_state_t *	s,
		int	method
	)

Set the method to be used for data rate management, as per the T.38 spec.

Parameters:

	s	The T.38 context.
	method	1 for pass TCF across the T.38 link, 2 for handle TCF locally.

References t38_core_state_s::data_rate_management_method.

void t38_set_data_transport_protocol	(	t38_core_state_t *	s,
		int	data_transport_protocol
	)

Set the data transport protocol.

Parameters:

	s	The T.38 context.
	data_transport_protocol	UDPTL, RTP or TPKT.

References t38_core_state_s::data_transport_protocol.

void t38_set_fill_bit_removal	(	t38_core_state_t *	s,
		int	fill_bit_removal
	)

Set the non-ECM fill bit removal mode.

Parameters:

	s	The T.38 context.
	fill_bit_removal	TRUE to remove fill bits across the T.38 link, else FALSE.

References t38_core_state_s::fill_bit_removal.

void t38_set_jbig_transcoding	(	t38_core_state_t *	s,
		int	jbig_transcoding
	)

Set the JBIG transcoding mode.

Parameters:

	s	The T.38 context.
	jbig_transcoding	TRUE to transcode to JBIG across the T.38 link, else FALSE.

References t38_core_state_s::jbig_transcoding.

void t38_set_mmr_transcoding	(	t38_core_state_t *	s,
		int	mmr_transcoding
	)

Set the MMR transcoding mode.

Parameters:

	s	The T.38 context.
	mmr_transcoding	TRUE to transcode to MMR across the T.38 link, else FALSE.

References t38_core_state_s::mmr_transcoding.

void t38_set_t38_version	(	t38_core_state_t *	s,
		int	t38_version
	)

Set the T.38 version to be emulated.

Parameters:

	s	The T.38 context.
	t38_version	Version number, as in the T.38 spec.

References t38_core_state_s::t38_version.

int t38_v34rate_to_bps	(	const uint8_t *	data,
		int	len
	)

Convert a V34rate message to an actual bit rate.

Parameters:

	data	The data field of the message.
	len	The length of the data field.

Returns:

The bit rate, or -1 for a bad message.