private/echo.h
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/*
* SpanDSP - a series of DSP components for telephony
*
* private/echo.h - An echo cancellor, suitable for electrical and acoustic
* cancellation. This code does not currently comply with
* any relevant standards (e.g. G.164/5/7/8).
*
* Written by Steve Underwood <steveu@coppice.org>
*
* Copyright (C) 2001 Steve Underwood
*
* All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License version 2.1,
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/*! \file */
#if !defined(_SPANDSP_PRIVATE_ECHO_H_)
#define _SPANDSP_PRIVATE_ECHO_H_
/*!
G.168 echo canceller descriptor. This defines the working state for a line
echo canceller.
*/
struct echo_can_state_s
{
int tx_power[4];
int rx_power[3];
int clean_rx_power;
int rx_power_threshold;
int nonupdate_dwell;
int curr_pos;
int taps;
int tap_mask;
int adaption_mode;
int32_t supp_test1;
int32_t supp_test2;
int32_t supp1;
int32_t supp2;
int vad;
int cng;
int16_t geigel_max;
int geigel_lag;
int dtd_onset;
int tap_set;
int tap_rotate_counter;
int32_t latest_correction; /* Indication of the magnitude of the latest
adaption, or a code to indicate why adaption
was skipped, for test purposes */
int32_t last_acf[28];
int narrowband_count;
int narrowband_score;
fir16_state_t fir_state;
/*! Echo FIR taps (16 bit version) */
int16_t *fir_taps16[4];
/*! Echo FIR taps (32 bit version) */
int32_t *fir_taps32;
/* DC and near DC blocking filter states */
int32_t tx_hpf[2];
int32_t rx_hpf[2];
/* Parameters for the optional Hoth noise generator */
int cng_level;
int cng_rndnum;
int cng_filter;
/* Snapshot sample of coeffs used for development */
int16_t *snapshot;
};
#endif
/*- End of file ------------------------------------------------------------*/
echo_can_state_s
Definition private/echo.h:38
echo_can_state_s::fir_taps32
int32_t * fir_taps32
Definition private/echo.h:76
echo_can_state_s::fir_taps16
int16_t * fir_taps16[4]
Definition private/echo.h:74
fir16_state_t
Definition fir.h:46