spandsp  0.0.6
fax_modems.h File Reference

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Typedefs

typedef struct fax_modems_state_s fax_modems_state_t
 

Enumerations

enum  {
  FAX_MODEM_NONE = -1, FAX_MODEM_FLUSH = 0, FAX_MODEM_SILENCE_TX, FAX_MODEM_SILENCE_RX,
  FAX_MODEM_CED_TONE, FAX_MODEM_CNG_TONE, FAX_MODEM_NOCNG_TONE, FAX_MODEM_V21_TX,
  FAX_MODEM_V17_TX, FAX_MODEM_V27TER_TX, FAX_MODEM_V29_TX, FAX_MODEM_V21_RX,
  FAX_MODEM_V17_RX, FAX_MODEM_V27TER_RX, FAX_MODEM_V29_RX
}
 

Functions

const char * fax_modem_to_str (int modem)
 Convert a FAX modem type to a short text description. More...
 
 SPAN_DECLARE_NONSTD (int) fax_modems_v17_v21_rx(void *user_data
 Get the next bit of a transmitted serial bit stream. More...
 
 SPAN_DECLARE_NONSTD (void) fax_modems_hdlc_tx_frame(void *user_data
 
void fax_modems_start_rx_modem (fax_modems_state_t *s, int which)
 
void fax_modems_set_tep_mode (fax_modems_state_t *s, int use_tep)
 
int fax_modems_restart (fax_modems_state_t *s)
 
logging_state_tfax_modems_get_logging_state (fax_modems_state_t *s)
 Get a pointer to the logging context associated with a FAX modems context. More...
 
fax_modems_state_tfax_modems_init (fax_modems_state_t *s, int use_tep, hdlc_frame_handler_t hdlc_accept, hdlc_underflow_handler_t hdlc_tx_underflow, put_bit_func_t non_ecm_put_bit, get_bit_func_t non_ecm_get_bit, tone_report_func_t tone_callback, void *user_data)
 
int fax_modems_release (fax_modems_state_t *s)
 
int fax_modems_free (fax_modems_state_t *s)
 

Variables

const int16_t amp []
 
const int16_t int len
 
const uint8_t * msg
 

Typedef Documentation

◆ fax_modems_state_t

The set of modems needed for FAX, plus the auxilliary stuff, like tone generation.

Function Documentation

◆ fax_modem_to_str()

const char* fax_modem_to_str ( int  modem)

Convert a FAX modem type to a short text description.

Convert a FAX modem type to a short text description.

Parameters
modemThe modem code.
Returns
A pointer to the description.

◆ fax_modems_get_logging_state()

logging_state_t* fax_modems_get_logging_state ( fax_modems_state_t s)

Get a pointer to the logging context associated with a FAX modems context.

Get a pointer to the logging context associated with a FAX modems context.

Parameters
sThe FAX modems context.
Returns
A pointer to the logging context, or NULL.

References fax_modems_state_s::logging.

◆ SPAN_DECLARE_NONSTD()

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.

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_dataAn 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
sThe FAX context.
lenThe 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
sThe FAX context.
ampThe audio sample buffer.
max_lenThe 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
sThe modem context.
ampThe audio sample buffer.
lenThe 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
sThe modem context.
lenThe number of samples to fake.
Returns
The number of samples unprocessed.
Parameters
sA pointer to an HDLC transmitter context.
Returns
The next byte for transmission.
Parameters
sA pointer to an HDLC transmitter context.
bufThe buffer for the data.
max_lenThe number of bytes to get.
Returns
The number of bytes actually got.
Parameters
sThe context.
ampAn array of signal samples.
lenThe 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_dataThe context.
ampThe signal.buffer
lenThe 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_dataThe context.
lenThe 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
sThe T.31 modem context.
lenThe number of samples to fake.
Returns
The number of samples unprocessed.

Generate a block of T.31 modem audio samples.

Parameters
sThe T.31 modem context.
ampThe audio sample buffer.
max_lenThe number of samples to be generated.
Returns
The number of samples actually generated.
Parameters
sThe T.38 context.
bufThe packet contents.
lenThe length of the packet contents.
seq_noThe 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
sThe T.38 context.
lenThe 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
sThe T.38 context.
ampThe audio sample buffer.
max_lenThe 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
sThe modem context.
lenThe number of samples to fake.
Returns
The number of samples unprocessed.

Process a block of received V.18 audio samples.

Parameters
sThe V.18 context.
ampThe audio sample buffer.
lenThe 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
sThe modem context.
lenThe number of samples to fake.
Returns
The number of samples unprocessed.

Generate a block of V.22bis modem audio samples.

Parameters
sThe modem context.
ampThe audio sample buffer.
lenThe 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
sThe modem context.
lenThe 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
sThe modem context.
lenThe number of samples to fake.
Returns
The number of samples unprocessed.

Process a block of received V.8 audio samples.

Parameters
sThe V.8 context.
ampThe audio sample buffer.
lenThe 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
sThe FAX context.
ampThe audio sample buffer.
lenThe 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
sThe FAX context.
lenThe 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
sThe FAX context.
ampThe audio sample buffer.
max_lenThe number of samples to be generated.
Returns
The number of samples actually generated. This will be zero when there is nothing to send.