Macros
#define	MODEM_CONNECT_TONES_FAX_CED MODEM_CONNECT_TONES_ANS
	FAX CED tone is the same as ANS tone.

Typedefs
typedef struct modem_connect_tones_tx_state_s	modem_connect_tones_tx_state_t
typedef struct modem_connect_tones_rx_state_s	modem_connect_tones_rx_state_t

Enumerations
enum	{ MODEM_CONNECT_TONES_NONE = 0 , MODEM_CONNECT_TONES_FAX_CNG = 1 , MODEM_CONNECT_TONES_ANS = 2 , MODEM_CONNECT_TONES_ANS_PR = 3 , MODEM_CONNECT_TONES_ANSAM = 4 , MODEM_CONNECT_TONES_ANSAM_PR = 5 , MODEM_CONNECT_TONES_FAX_PREAMBLE = 6 , MODEM_CONNECT_TONES_FAX_CED_OR_PREAMBLE = 7 , MODEM_CONNECT_TONES_BELL_ANS = 8 , MODEM_CONNECT_TONES_CALLING_TONE = 9 }

Functions
modem_connect_tones_tx_state_t *	modem_connect_tones_tx_init (modem_connect_tones_tx_state_t *s, int tone_type)
	Initialise an instance of the modem connect tones generator.
int	modem_connect_tones_tx_release (modem_connect_tones_tx_state_t *s)
	Release an instance of the modem connect tones generator.
int	modem_connect_tones_tx_free (modem_connect_tones_tx_state_t *s)
	Free an instance of the modem connect tones generator.
	SPAN_DECLARE_NONSTD (int) modem_connect_tones_tx(modem_connect_tones_tx_state_t *s
	Generate a block of modem connect tones samples.
int	modem_connect_tones_rx_get (modem_connect_tones_rx_state_t *s)
	Test if a modem_connect tone has been detected.
modem_connect_tones_rx_state_t *	modem_connect_tones_rx_init (modem_connect_tones_rx_state_t s, int tone_type, tone_report_func_t tone_callback, void user_data)
	Initialise an instance of the modem connect tones detector.
int	modem_connect_tones_rx_release (modem_connect_tones_rx_state_t *s)
	Release an instance of the modem connect tones detector.
int	modem_connect_tones_rx_free (modem_connect_tones_rx_state_t *s)
	Free an instance of the modem connect tones detector.
const char *	modem_connect_tone_to_str (int tone)

Variables
int16_t	amp []
int16_t int	len

Typedef Documentation

◆ modem_connect_tones_rx_state_t

typedef struct modem_connect_tones_rx_state_s modem_connect_tones_rx_state_t

Modem connect tones receiver descriptor. This defines the state of a single working instance of the tone detector.

◆ modem_connect_tones_tx_state_t

typedef struct modem_connect_tones_tx_state_s modem_connect_tones_tx_state_t

Modem connect tones generator descriptor. This defines the state of a single working instance of the tone generator.

Enumeration Type Documentation

◆ anonymous enum

anonymous enum

Enumerator
MODEM_CONNECT_TONES_NONE	This is reported when a tone stops.
MODEM_CONNECT_TONES_FAX_CNG	CNG tone is a pure 1100Hz tone, in 0.5s bursts, with 3s silences in between. The bursts repeat for as long as is required.
MODEM_CONNECT_TONES_ANS	ANS tone is a pure continuous 2100Hz+-15Hz tone for 3.3s+-0.7s.
MODEM_CONNECT_TONES_ANS_PR	ANS with phase reversals tone is a 2100Hz+-15Hz tone for 3.3s+-0.7s, with a 180 degree phase jump every 450ms+-25ms.
MODEM_CONNECT_TONES_ANSAM	The ANSam tone is a version of ANS with 20% of 15Hz+-0.1Hz AM modulation, as per V.8.
MODEM_CONNECT_TONES_ANSAM_PR	The ANSam with phase reversals tone is a version of ANS_PR with 20% of 15Hz+-0.1Hz AM modulation, as per V.8.
MODEM_CONNECT_TONES_FAX_PREAMBLE	FAX preamble in a string of V.21 HDLC flag octets.
MODEM_CONNECT_TONES_FAX_CED_OR_PREAMBLE	CED tone is the same as ANS tone. FAX preamble in a string of V.21 HDLC flag octets. This is only valid as a tone type to receive. It is never reported as a detected tone type. The report will either be for FAX preamble or CED/ANS tone.
MODEM_CONNECT_TONES_BELL_ANS	Bell ANS tone is a pure continuous 2225Hz+-15Hz tone for 3.3s+-0.7s.
MODEM_CONNECT_TONES_CALLING_TONE	Calling tone is a pure 1300Hz tone, in 0.6s bursts, with 2s silences in between. The bursts repeat for as long as is required.

Function Documentation

◆ modem_connect_tones_rx_free()

int modem_connect_tones_rx_free ( modem_connect_tones_rx_state_t * s )

Free an instance of the modem connect tones detector.

Parameters

s	The context.

Returns: 0 for OK, else -1.

◆ modem_connect_tones_rx_get()

int modem_connect_tones_rx_get ( modem_connect_tones_rx_state_t * s )

Test if a modem_connect tone has been detected.

Parameters

s	The context.

Returns: TRUE if tone is detected, else FALSE.

References modem_connect_tones_rx_state_s::hit, and MODEM_CONNECT_TONES_NONE.

◆ modem_connect_tones_rx_init()

modem_connect_tones_rx_state_t * modem_connect_tones_rx_init	(	modem_connect_tones_rx_state_t *	s,
		int	tone_type,
		tone_report_func_t	tone_callback,
		void *	user_data )

Initialise an instance of the modem connect tones detector.

Parameters

s	The context.
tone_type	The type of connect tone being tested for.
tone_callback	An optional callback routine, used to report tones
user_data	An opaque pointer passed to the callback routine,

Returns: A pointer to the context.

References modem_connect_tones_rx_state_s::am_level, modem_connect_tones_rx_state_s::callback_data, modem_connect_tones_rx_state_s::channel_level, modem_connect_tones_rx_state_s::flags_seen, modem_connect_tones_rx_state_s::framing_ok_announced, fsk_rx_init(), fsk_rx_signal_cutoff(), modem_connect_tones_rx_state_s::good_cycles, modem_connect_tones_rx_state_s::hit, MODEM_CONNECT_TONES_ANS, MODEM_CONNECT_TONES_ANS_PR, MODEM_CONNECT_TONES_ANSAM, MODEM_CONNECT_TONES_ANSAM_PR, MODEM_CONNECT_TONES_FAX_CED_OR_PREAMBLE, MODEM_CONNECT_TONES_FAX_PREAMBLE, MODEM_CONNECT_TONES_NONE, modem_connect_tones_rx_state_s::notch_level, modem_connect_tones_rx_state_s::num_bits, modem_connect_tones_rx_state_s::raw_bit_stream, modem_connect_tones_rx_state_s::tone_callback, modem_connect_tones_rx_state_s::tone_cycle_duration, modem_connect_tones_rx_state_s::tone_present, modem_connect_tones_rx_state_s::tone_type, modem_connect_tones_rx_state_s::v21rx, modem_connect_tones_rx_state_s::z15hz_1, and modem_connect_tones_rx_state_s::znotch_1.

◆ modem_connect_tones_rx_release()

int modem_connect_tones_rx_release ( modem_connect_tones_rx_state_t * s )

Release an instance of the modem connect tones detector.

Parameters

s	The context.

Returns: 0 for OK, else -1.

◆ modem_connect_tones_tx_free()

int modem_connect_tones_tx_free ( modem_connect_tones_tx_state_t * s )

Free an instance of the modem connect tones generator.

Parameters

s	The context.

Returns: 0 for OK, else -1.

◆ modem_connect_tones_tx_init()

modem_connect_tones_tx_state_t * modem_connect_tones_tx_init	(	modem_connect_tones_tx_state_t *	s,
		int	tone_type )

Initialise an instance of the modem connect tones generator.

Parameters

s	The context.

References dds_phase_rate(), dds_scaling_dbm0(), modem_connect_tones_tx_state_s::duration_timer, modem_connect_tones_tx_state_s::hop_timer, MODEM_CONNECT_TONES_ANS, MODEM_CONNECT_TONES_ANS_PR, MODEM_CONNECT_TONES_ANSAM, MODEM_CONNECT_TONES_ANSAM_PR, MODEM_CONNECT_TONES_BELL_ANS, MODEM_CONNECT_TONES_CALLING_TONE, and MODEM_CONNECT_TONES_FAX_CNG.

◆ modem_connect_tones_tx_release()

int modem_connect_tones_tx_release ( modem_connect_tones_tx_state_t * s )

Release an instance of the modem connect tones generator.

Parameters

s	The context.

Returns: 0 for OK, else -1.

◆ SPAN_DECLARE_NONSTD()

SPAN_DECLARE_NONSTD ( int )

Generate a block of modem connect tones samples.

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.

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.

Macros

Typedefs

Enumerations

Functions

Variables

Typedef Documentation

◆ modem_connect_tones_rx_state_t

◆ modem_connect_tones_tx_state_t

Enumeration Type Documentation

◆ anonymous enum

Function Documentation

◆ modem_connect_tones_rx_free()

◆ modem_connect_tones_rx_get()

◆ modem_connect_tones_rx_init()

◆ modem_connect_tones_rx_release()

◆ modem_connect_tones_tx_free()

◆ modem_connect_tones_tx_init()

◆ modem_connect_tones_tx_release()

◆ SPAN_DECLARE_NONSTD()