v18.h File Reference

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Typedefs
typedef struct v18_state_s	v18_state_t

Enumerations
enum	{   V18_MODE_NONE = 0 , V18_MODE_5BIT_45 = 1 , V18_MODE_5BIT_50 = 2 , V18_MODE_DTMF = 3 ,   V18_MODE_EDT = 4 , V18_MODE_BELL103 = 5 , V18_MODE_V23VIDEOTEX = 6 , V18_MODE_V21TEXTPHONE = 7 ,   V18_MODE_V18TEXTPHONE = 8 }

Functions
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.
	SPAN_DECLARE_NONSTD (int) v18_tx(v18_state_t *s
	Generate a block of V.18 audio samples.
int	v18_put (v18_state_t *s, const char msg[], int len)
	Put a string to a V.18 context's input buffer.
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)
const char *	v18_mode_to_str (int mode)
	Return a short name for an V.18 mode.

Variables
int16_t	amp []
int16_t int	max_len
const int16_t int	len

Function Documentation

SPAN_DECLARE_NONSTD()

SPAN_DECLARE_NONSTD

(

int

)

Generate a block of V.18 audio samples.

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.

Apply T.30 receive processing to a block of audio samples.

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.

Process a received T.38 IFP packet from a reliable stream (e.g. TCP).

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.

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.

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.

Parameters

s	The T.38 context.
buf	The packet contents.
len	The length of the packet contents.
seq_no	The packet sequence number, used for logging purposes.

Returns

The length of the packet processed, or -1 if there is an error in the packet, or too few bytes of data to complete it.

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.

v18_decode_dtmf()

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.

v18_encode_dtmf()

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.

v18_free()

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_init()

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_EVEN, ASYNC_PARITY_NONE, async_tx_init(), v18_state_s::calling_party, dtmf_rx_init(), dtmf_tx_init(), fsk_rx_init(), fsk_tx_init(), queue_init(), QUEUE_READ_ATOMIC, and QUEUE_WRITE_ATOMIC.

v18_mode_to_str()

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.

v18_put()

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().

v18_release()

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.