modem_echo.c File Reference

#include <stdlib.h>
#include <inttypes.h>
#include <string.h>
#include <stdio.h>
#include "floating_fudge.h"
#include "spandsp/telephony.h"
#include "spandsp/bit_operations.h"
#include "spandsp/dc_restore.h"
#include "spandsp/modem_echo.h"

Functions
modem_echo_can_state_t *	modem_echo_can_create (int len)
void	modem_echo_can_free (modem_echo_can_state_t *ec)
void	modem_echo_can_flush (modem_echo_can_state_t *ec)
void	modem_echo_can_adaption_mode (modem_echo_can_state_t *ec, int adapt)
int16_t	modem_echo_can_update (modem_echo_can_state_t *ec, int16_t tx, int16_t rx)

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Detailed Description

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Function Documentation

void modem_echo_can_adaption_mode	(	modem_echo_can_state_t *	ec,
		int	adapt
	)

Set the adaption mode of a modem echo canceller context.

Parameters:

	ec	The echo canceller context.
	adapt	The mode.

References modem_echo_can_state_t::adapt.

modem_echo_can_state_t* modem_echo_can_create

(

int

len

)

Create a modem echo canceller context.

Parameters:

len

The length of the canceller, in samples. eturn The new canceller context, or NULL if the canceller could not be created.

References modem_echo_can_state_t::curr_pos, modem_echo_can_state_t::fir_state, modem_echo_can_state_t::fir_taps16, modem_echo_can_state_t::fir_taps32, and modem_echo_can_state_t::taps.

void modem_echo_can_flush

(

modem_echo_can_state_t *

ec

)

Flush (reinitialise) a modem echo canceller context.

Parameters:

ec

The echo canceller context.

References modem_echo_can_state_t::curr_pos, fir16_state_t::curr_pos, modem_echo_can_state_t::fir_state, modem_echo_can_state_t::fir_taps16, modem_echo_can_state_t::fir_taps32, modem_echo_can_state_t::taps, and modem_echo_can_state_t::tx_power.

void modem_echo_can_free

(

modem_echo_can_state_t *

ec

)

Free a modem echo canceller context.

Parameters:

ec

The echo canceller context.

References modem_echo_can_state_t::fir_state, modem_echo_can_state_t::fir_taps16, and modem_echo_can_state_t::fir_taps32.

int16_t modem_echo_can_update	(	modem_echo_can_state_t *	ec,
		int16_t	tx,
		int16_t	rx
	)

Process a sample through a modem echo canceller.

Parameters:

	ec	The echo canceller context.
	tx	The transmitted audio sample.
	rx	The received audio sample. eturn The clean (echo cancelled) received sample.

References modem_echo_can_state_t::adapt, modem_echo_can_state_t::curr_pos, modem_echo_can_state_t::fir_state, modem_echo_can_state_t::fir_taps16, modem_echo_can_state_t::fir_taps32, fir16_state_t::history, modem_echo_can_state_t::taps, and modem_echo_can_state_t::tx_power.