v29rx.c File Reference

#include <stdlib.h>
#include <inttypes.h>
#include <string.h>
#include <stdio.h>
#include <tgmath.h>
#include <math.h>
#include "floating_fudge.h"
#include "spandsp/telephony.h"
#include "spandsp/logging.h"
#include "spandsp/complex.h"
#include "spandsp/vector_float.h"
#include "spandsp/complex_vector_float.h"
#include "spandsp/vector_int.h"
#include "spandsp/complex_vector_int.h"
#include "spandsp/async.h"
#include "spandsp/power_meter.h"
#include "spandsp/arctan2.h"
#include "spandsp/dds.h"
#include "spandsp/complex_filters.h"
#include "spandsp/v29rx.h"
#include "spandsp/private/logging.h"
#include "spandsp/private/v29rx.h"
#include "v29tx_constellation_maps.h"
#include "v29rx_floating_rrc.h"

Defines

#define IAXMODEM_STUFF
#define CARRIER_NOMINAL_FREQ   1700.0f
#define BAUD_RATE   2400
#define EQUALIZER_DELTA   0.21f
#define V29_TRAINING_SEG_2_LEN   128
#define V29_TRAINING_SEG_3_LEN   384
#define V29_TRAINING_SEG_4_LEN   48
#define SIN_LOW_BAND_EDGE   0.382683432f
#define COS_LOW_BAND_EDGE   0.923879533f
#define SIN_HIGH_BAND_EDGE   0.760405966f
#define COS_HIGH_BAND_EDGE   -0.649448048f
#define ALPHA   0.99f
#define SYNC_LOW_BAND_EDGE_COEFF_0   (2.0f*ALPHA*COS_LOW_BAND_EDGE)
#define SYNC_LOW_BAND_EDGE_COEFF_1   (-ALPHA*ALPHA)
#define SYNC_LOW_BAND_EDGE_COEFF_2   (-ALPHA*SIN_LOW_BAND_EDGE)
#define SYNC_HIGH_BAND_EDGE_COEFF_0   (2.0f*ALPHA*COS_HIGH_BAND_EDGE)
#define SYNC_HIGH_BAND_EDGE_COEFF_1   (-ALPHA*ALPHA)
#define SYNC_HIGH_BAND_EDGE_COEFF_2   (-ALPHA*SIN_HIGH_BAND_EDGE)
#define SYNC_MIXED_EDGES_COEFF_3   (-ALPHA*ALPHA*(SIN_HIGH_BAND_EDGE*COS_LOW_BAND_EDGE - SIN_LOW_BAND_EDGE*COS_HIGH_BAND_EDGE))

Enumerations

enum  {
  TRAINING_STAGE_NORMAL_OPERATION = 0, TRAINING_STAGE_SYMBOL_ACQUISITION, TRAINING_STAGE_LOG_PHASE, TRAINING_STAGE_WAIT_FOR_CDCD,
  TRAINING_STAGE_TRAIN_ON_CDCD, TRAINING_STAGE_TRAIN_ON_CDCD_AND_TEST, TRAINING_STAGE_TEST_ONES, TRAINING_STAGE_PARKED
}

Functions

float v29_rx_carrier_frequency (v29_rx_state_t *s)
float v29_rx_symbol_timing_correction (v29_rx_state_t *s)
float v29_rx_signal_power (v29_rx_state_t *s)
void v29_rx_signal_cutoff (v29_rx_state_t *s, float cutoff)
int v29_rx_equalizer_state (v29_rx_state_t *s, complexf_t **coeffs)
 Get a snapshot of the current equalizer coefficients.
 SPAN_DECLARE_NONSTD (int)
 Get the next bit of a transmitted serial bit stream.
void v29_rx_set_put_bit (v29_rx_state_t *s, put_bit_func_t put_bit, void *user_data)
 Change the put_bit function associated with a V.29 modem receive context.
void v29_rx_set_modem_status_handler (v29_rx_state_t *s, modem_tx_status_func_t handler, void *user_data)
 Change the modem status report function associated with a V.29 modem receive context.
logging_state_tv29_rx_get_logging_state (v29_rx_state_t *s)
 Get the logging context associated with a V.29 modem receive context.
int v29_rx_restart (v29_rx_state_t *s, int bit_rate, int old_train)
 Reinitialise an existing V.29 modem receive context.
v29_rx_state_tv29_rx_init (v29_rx_state_t *s, int bit_rate, put_bit_func_t put_bit, void *user_data)
 Initialise a V.29 modem receive context.
int v29_rx_release (v29_rx_state_t *s)
 Release a V.29 modem receive context.
int v29_rx_free (v29_rx_state_t *s)
 Free a V.29 modem receive context.
void v29_rx_set_qam_report_handler (v29_rx_state_t *s, qam_report_handler_t handler, void *user_data)

Detailed Description


Define Documentation

#define BAUD_RATE   2400

The nominal baud or symbol rate

#define CARRIER_NOMINAL_FREQ   1700.0f

The nominal frequency of the carrier, in Hertz

#define EQUALIZER_DELTA   0.21f

The adaption rate coefficient for the equalizer

#define V29_TRAINING_SEG_2_LEN   128

The length of training segment 2, in symbols

#define V29_TRAINING_SEG_3_LEN   384

The length of training segment 3, in symbols

#define V29_TRAINING_SEG_4_LEN   48

The length of training segment 4, in symbols


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 dds_advance(), dds_advancef(), and span_log().

float v29_rx_carrier_frequency ( v29_rx_state_t s  ) 

Get the current received carrier frequency.

Parameters:
s The modem context.
Returns:
The frequency, in Hertz.

References dds_frequencyf().

int v29_rx_equalizer_state ( v29_rx_state_t s,
complexf_t **  coeffs 
)

Get a snapshot of the current equalizer coefficients.

Get a snapshot of the current equalizer coefficients.

Parameters:
s The modem context.
coeffs The vector of complex coefficients.
Returns:
The number of coefficients in the vector.
int v29_rx_free ( v29_rx_state_t s  ) 

Free a V.29 modem receive context.

Free a V.29 modem receive context.

Parameters:
s The modem context.
Returns:
0 for OK
logging_state_t* v29_rx_get_logging_state ( v29_rx_state_t s  ) 

Get the logging context associated with a V.29 modem receive context.

Get the logging context associated with a V.29 modem receive context.

Parameters:
s The modem context.
Returns:
A pointer to the logging context
v29_rx_state_t* v29_rx_init ( v29_rx_state_t s,
int  bit_rate,
put_bit_func_t  put_bit,
void *  user_data 
)

Initialise a V.29 modem receive context.

Initialise a V.29 modem receive context.

Parameters:
s The modem context.
bit_rate The bit rate of the modem. Valid values are 4800, 7200 and 9600.
put_bit The callback routine used to put the received data.
user_data An opaque pointer passed to the put_bit routine.
Returns:
A pointer to the modem context, or NULL if there was a problem.

References v29_rx_restart(), and v29_rx_signal_cutoff().

int v29_rx_release ( v29_rx_state_t s  ) 

Release a V.29 modem receive context.

Release a V.29 modem receive context.

Parameters:
s The modem context.
Returns:
0 for OK
int v29_rx_restart ( v29_rx_state_t s,
int  bit_rate,
int  old_train 
)

Reinitialise an existing V.29 modem receive context.

Reinitialise an existing V.29 modem receive context.

Parameters:
s The modem context.
bit_rate The bit rate of the modem. Valid values are 4800, 7200 and 9600.
old_train TRUE if a previous trained values are to be reused.
Returns:
0 for OK, -1 for bad parameter

References CARRIER_NOMINAL_FREQ, dds_phase_ratef(), and power_meter_init().

Referenced by v29_rx_init().

void v29_rx_set_modem_status_handler ( v29_rx_state_t s,
modem_rx_status_func_t  handler,
void *  user_data 
)

Change the modem status report function associated with a V.29 modem receive context.

Change the modem status report function associated with a V.29 modem receive context.

Parameters:
s The modem context.
handler The callback routine used to report modem status changes.
user_data An opaque pointer.
void v29_rx_set_put_bit ( v29_rx_state_t s,
put_bit_func_t  put_bit,
void *  user_data 
)

Change the put_bit function associated with a V.29 modem receive context.

Change the put_bit function associated with a V.29 modem receive context.

Parameters:
s The modem context.
put_bit The callback routine used to handle received bits.
user_data An opaque pointer.
void v29_rx_set_qam_report_handler ( v29_rx_state_t s,
qam_report_handler_t  handler,
void *  user_data 
)

Set a handler routine to process QAM status reports

Parameters:
s The modem context.
handler The handler routine.
user_data An opaque pointer passed to the handler routine.
void v29_rx_signal_cutoff ( v29_rx_state_t s,
float  cutoff 
)

Set the power level at which the carrier detection will cut in

Parameters:
s The modem context.
cutoff The signal cutoff power, in dBm0.

References power_meter_level_dbm0().

Referenced by v29_rx_init().

float v29_rx_signal_power ( v29_rx_state_t s  ) 

Get the current received signal power.

Parameters:
s The modem context.
Returns:
The signal power, in dBm0.

References power_meter_current_dbm0().

float v29_rx_symbol_timing_correction ( v29_rx_state_t s  ) 

Get the current symbol timing correction since startup.

Parameters:
s The modem context.
Returns:
The correction.

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