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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:02:30 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:02:30 +0000 |
commit | 76cb841cb886eef6b3bee341a2266c76578724ad (patch) | |
tree | f5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /drivers/misc/echo/oslec.h | |
parent | Initial commit. (diff) | |
download | linux-76cb841cb886eef6b3bee341a2266c76578724ad.tar.xz linux-76cb841cb886eef6b3bee341a2266c76578724ad.zip |
Adding upstream version 4.19.249.upstream/4.19.249
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/misc/echo/oslec.h')
-rw-r--r-- | drivers/misc/echo/oslec.h | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/drivers/misc/echo/oslec.h b/drivers/misc/echo/oslec.h new file mode 100644 index 000000000..f4175360c --- /dev/null +++ b/drivers/misc/echo/oslec.h @@ -0,0 +1,94 @@ +/* + * OSLEC - A line echo canceller. This code is being developed + * against and partially complies with G168. Using code from SpanDSP + * + * Written by Steve Underwood <steveu@coppice.org> + * and David Rowe <david_at_rowetel_dot_com> + * + * Copyright (C) 2001 Steve Underwood and 2007-2008 David Rowe + * + * All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2, 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 General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + * + */ + +#ifndef __OSLEC_H +#define __OSLEC_H + +/* Mask bits for the adaption mode */ +#define ECHO_CAN_USE_ADAPTION 0x01 +#define ECHO_CAN_USE_NLP 0x02 +#define ECHO_CAN_USE_CNG 0x04 +#define ECHO_CAN_USE_CLIP 0x08 +#define ECHO_CAN_USE_TX_HPF 0x10 +#define ECHO_CAN_USE_RX_HPF 0x20 +#define ECHO_CAN_DISABLE 0x40 + +/** + * oslec_state: G.168 echo canceller descriptor. + * + * This defines the working state for a line echo canceller. + */ +struct oslec_state; + +/** + * oslec_create - Create a voice echo canceller context. + * @len: The length of the canceller, in samples. + * @return: The new canceller context, or NULL if the canceller could not be + * created. + */ +struct oslec_state *oslec_create(int len, int adaption_mode); + +/** + * oslec_free - Free a voice echo canceller context. + * @ec: The echo canceller context. + */ +void oslec_free(struct oslec_state *ec); + +/** + * oslec_flush - Flush (reinitialise) a voice echo canceller context. + * @ec: The echo canceller context. + */ +void oslec_flush(struct oslec_state *ec); + +/** + * oslec_adaption_mode - set the adaption mode of a voice echo canceller context. + * @ec The echo canceller context. + * @adaption_mode: The mode. + */ +void oslec_adaption_mode(struct oslec_state *ec, int adaption_mode); + +void oslec_snapshot(struct oslec_state *ec); + +/** + * oslec_update: Process a sample through a voice echo canceller. + * @ec: The echo canceller context. + * @tx: The transmitted audio sample. + * @rx: The received audio sample. + * + * The return value is the clean (echo cancelled) received sample. + */ +int16_t oslec_update(struct oslec_state *ec, int16_t tx, int16_t rx); + +/** + * oslec_hpf_tx: Process to high pass filter the tx signal. + * @ec: The echo canceller context. + * @tx: The transmitted auio sample. + * + * The return value is the HP filtered transmit sample, send this to your D/A. + */ +int16_t oslec_hpf_tx(struct oslec_state *ec, int16_t tx); + +#endif /* __OSLEC_H */ |