v18.c File Reference

#include <inttypes.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <memory.h>
#include <tgmath.h>
#include <math.h>
#include "floating_fudge.h"
#include "spandsp/telephony.h"
#include "spandsp/logging.h"
#include "spandsp/queue.h"
#include "spandsp/async.h"
#include "spandsp/complex.h"
#include "spandsp/dds.h"
#include "spandsp/tone_detect.h"
#include "spandsp/tone_generate.h"
#include "spandsp/super_tone_rx.h"
#include "spandsp/power_meter.h"
#include "spandsp/fsk.h"
#include "spandsp/dtmf.h"
#include "spandsp/modem_connect_tones.h"
#include "spandsp/v8.h"
#include "spandsp/v18.h"
#include "spandsp/private/logging.h"
#include "spandsp/private/queue.h"
#include "spandsp/private/tone_generate.h"
#include "spandsp/private/async.h"
#include "spandsp/private/fsk.h"
#include "spandsp/private/dtmf.h"
#include "spandsp/private/modem_connect_tones.h"
#include "spandsp/private/v18.h"

Classes
struct	dtmf_to_ascii_s
Defines
#define	BAUDOT_FIGURE_SHIFT   0x1B
#define	BAUDOT_LETTER_SHIFT   0x1F
Functions
int	v18_encode_dtmf (v18_state_t *s, char dtmf[], const char msg[])
	Convert a text string to a V.18 DTMF string.
int	v18_decode_dtmf (v18_state_t *s, char msg[], const char dtmf[])
	Convert a V.18 DTMF string to a text string.
uint16_t	v18_encode_baudot (v18_state_t *s, uint8_t ch)
uint8_t	v18_decode_baudot (v18_state_t *s, uint8_t ch)
	SPAN_DECLARE_NONSTD (int)
	Get the next bit of a transmitted serial bit stream.
int	v18_put (v18_state_t *s, const char msg[], int len)
	Put a string to a V.18 context's input buffer.
logging_state_t *	v18_get_logging_state (v18_state_t *s)
v18_state_t *	v18_init (v18_state_t *s, int calling_party, int mode, put_msg_func_t put_msg, void *user_data)
	Initialise a V.18 context.
int	v18_release (v18_state_t *s)
	Release a V.18 context.
int	v18_free (v18_state_t *s)
	Release a V.18 context.
const char *	v18_mode_to_str (int mode)
	Return a short name for an V.18 mode.

---

Detailed Description

---

Define Documentation

#define BAUDOT_FIGURE_SHIFT   0x1B

The baudot code to shift from alpha to digits and symbols

#define BAUDOT_LETTER_SHIFT   0x1F

The baudot code to shift from digits and symbols to alpha

---

Function Documentation

SPAN_DECLARE_NONSTD

(

int

)

Get the next bit of a transmitted serial bit stream.

Get the next bit of data from a T.38 rate adapting non-ECM buffer context.

Get a bit of received non-ECM image data.

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.

Get the next bit of a transmitted serial bit stream.

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.

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 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.

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.

Get the next bit of a transmitted serial bit stream.

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

Process a block of received FSK modem audio samples.

Generate a block of FSK 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.

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.

Get the next bit of a transmitted serial bit stream.

Get the next sequence of bytes for transmission.

Get the next byte for transmission.

Parameters:

s

A pointer to an HDLC transmitter context.

Returns:

The next bit for transmission.

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.

Get the next bit of a transmitted serial bit stream.

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

Parameters:

	s	The context.
	amp	An array of signal samples.
	len	The number of samples to generate.

Returns:

The number of samples generated.

Parameters:

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

Returns:

The number of unprocessed samples.

Get the next bit of a transmitted serial bit stream.

Dummy receive fillin callback.

Dummy receive callback.

Generate a block of silent audio samples.

Parameters:

	s	The silence generator 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.

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.

Get the next bit of a transmitted serial bit stream.

Generate a block of T.31 modem audio samples.

Fake processing of a missing 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.

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.

Get the next bit of a transmitted serial bit stream.

Generate a block of FAX audio samples.

Apply fake received audio processing.

Process a block of received FAX audio samples.

Parameters:

	s	The T.38 context.
	amp	The audio sample buffer.
	len	The number of samples in the buffer.

Returns:

The number of samples unprocessed.

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.

Get the next bit of a transmitted serial bit stream.

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

Process a block of received V.17 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.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.

Get the next bit of a transmitted serial bit stream.

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.

Get the next bit of a transmitted serial bit stream.

Process a block of received V.18 audio samples.

Generate a block of V.18 audio samples.

Parameters:

	s	The V.18 context.
	amp	The audio sample buffer.
	max_len	The number of samples to be generated.

Returns:

The number of samples actually generated.

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.

Get the next bit of a transmitted serial bit stream.

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.22bis 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.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.

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.

Get the next bit of a transmitted serial bit stream.

Generate a block of V.27ter 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.

Get the next bit of a transmitted serial bit stream.

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

Process a block of received V.29 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.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.

Get the next bit of a transmitted serial bit stream.

Generate a block of V.29 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.

Get the next bit of a transmitted serial bit stream.

Process a block of received V.8 audio samples.

Generate a block of V.8 audio samples.

Parameters:

	s	The V.8 context.
	amp	The audio sample buffer.
	max_len	The number of samples to be generated.

Returns:

The number of samples actually generated.

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.

References dtmf_rx().

int v18_decode_dtmf	(	v18_state_t *	s,
		char	msg[],
		const char	dtmf[]
	)

Convert a V.18 DTMF string to a text string.

Convert a V.18 DTMF string to a text string.

Parameters:

	s	The V.18 context.
	msg	The resulting test string.
	dtmf	The DTMF string to be converted.

Returns:

The length of the text string.

int v18_encode_dtmf	(	v18_state_t *	s,
		char	dtmf[],
		const char	msg[]
	)

Convert a text string to a V.18 DTMF string.

Convert a text string to a V.18 DTMF string.

Parameters:

	s	The V.18 context.
	dtmf	The resulting DTMF string.
	msg	The text string to be converted.

Returns:

The length of the DTMF string.

int v18_free

(

v18_state_t *

s

)

Release a V.18 context.

Free a V.18 context.

Parameters:

s

The V.18 context.

Returns:

0 for OK.

v18_state_t* v18_init	(	v18_state_t *	s,
		int	calling_party,
		int	mode,
		put_msg_func_t	put_msg,
		void *	user_data
	)

Initialise a V.18 context.

Initialise a V.18 context.

Parameters:

	s	The V.18 context.
	calling_party	TRUE if caller mode, else answerer mode.
	mode	Mode of operation.
	put_msg	A callback routine called to deliver the received text to the application.
	user_data	An opaque pointer for the callback routine.

Returns:

A pointer to the V.18 context, or NULL if there was a problem.

References ASYNC_PARITY_NONE, async_tx_init(), dtmf_rx_init(), dtmf_tx_init(), fsk_rx_init(), fsk_tx_init(), queue_init(), QUEUE_READ_ATOMIC, and QUEUE_WRITE_ATOMIC.

const char* v18_mode_to_str

(

int

mode

)

Return a short name for an V.18 mode.

Parameters:

mode

The code for the V.18 mode.

Returns:

A pointer to the name.

int v18_put	(	v18_state_t *	s,
		const char	msg[],
		int	len
	)

Put a string to a V.18 context's input buffer.

Parameters:

	s	The V.18 context.
	msg	The string to be added.
	len	The length of the string. If negative, the string is assumed to be a NULL terminated string.

Returns:

The number of characters actually added. This may be less than the length of the digit string, if the buffer fills up. If the string is invalid, this function will return -1.

References queue_write().

int v18_release

(

v18_state_t *

s

)

Release a V.18 context.

Release a V.18 context.

Parameters:

s

The V.18 context.

Returns:

0 for OK.