/* SPDX-License-Identifier: GPL-2.0-only */ /* * 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. */ #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 */