spandsp: echo.h Source File

spandsp 0.0.6

private/echo.h
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1/*
2 * SpanDSP - a series of DSP components for telephony
3 *
4 * private/echo.h - An echo cancellor, suitable for electrical and acoustic
5 * cancellation. This code does not currently comply with
6 * any relevant standards (e.g. G.164/5/7/8).
7 *
8 * Written by Steve Underwood <steveu@coppice.org>
9 *
10 * Copyright (C) 2001 Steve Underwood
11 *
12 * All rights reserved.
13 *
14 * This program is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU Lesser General Public License version 2.1,
16 * as published by the Free Software Foundation.
17 *
18 * This program is distributed in the hope that it will be useful,
19 * but WITHOUT ANY WARRANTY; without even the implied warranty of
20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21 * GNU Lesser General Public License for more details.
22 *
23 * You should have received a copy of the GNU Lesser General Public
24 * License along with this program; if not, write to the Free Software
25 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
26 */
27
28/*! \file */
29
30#if !defined(_SPANDSP_PRIVATE_ECHO_H_)
31#define _SPANDSP_PRIVATE_ECHO_H_
32
33/*!
34 G.168 echo canceller descriptor. This defines the working state for a line
35 echo canceller.
36*/
37 struct echo_can_state_s
38{
39 int tx_power[4];
40 int rx_power[3];
41 int clean_rx_power;
42
43 int rx_power_threshold;
44 int nonupdate_dwell;
45
46 int curr_pos;
47
48 int taps;
49 int tap_mask;
50 int adaption_mode;
51
52 int32_t supp_test1;
53 int32_t supp_test2;
54 int32_t supp1;
55 int32_t supp2;
56 int vad;
57 int cng;
58
59 int16_t geigel_max;
60 int geigel_lag;
61 int dtd_onset;
62 int tap_set;
63 int tap_rotate_counter;
64
65 int32_t latest_correction; /* Indication of the magnitude of the latest
66 adaption, or a code to indicate why adaption
67 was skipped, for test purposes */
68 int32_t last_acf[28];
69 int narrowband_count;
70 int narrowband_score;
71
72 fir16_state_t fir_state;
73 /*! Echo FIR taps (16 bit version) */
74 int16_t *fir_taps16[4];
75 /*! Echo FIR taps (32 bit version) */
76 int32_t *fir_taps32;
77
78 /* DC and near DC blocking filter states */
79 int32_t tx_hpf[2];
80 int32_t rx_hpf[2];
81
82 /* Parameters for the optional Hoth noise generator */
83 int cng_level;
84 int cng_rndnum;
85 int cng_filter;
86
87 /* Snapshot sample of coeffs used for development */
88 int16_t *snapshot;
89};
90
91#endif
92/*- 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