/* $Id$ */ /* * Copyright (C) 2008-2009 Teluu Inc. (http://www.teluu.com) * Copyright (C) 2003-2008 Benny Prijono * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #ifndef __PJMEDIA_ECHO_H__ #define __PJMEDIA_ECHO_H__ /** * @file echo.h * @brief Echo Cancellation API. */ #include /** * @defgroup PJMEDIA_Echo_Cancel Accoustic Echo Cancellation API * @ingroup PJMEDIA_PORT * @brief Echo Cancellation API. * @{ * * This section describes API to perform echo cancellation to audio signal. * There may be multiple echo canceller implementation in PJMEDIA, ranging * from simple echo suppressor to a full Accoustic Echo Canceller/AEC. By * using this API, application should be able to use which EC backend to * use base on the requirement and capability of the platform. */ PJ_BEGIN_DECL /** * Opaque type for PJMEDIA Echo Canceller state. */ typedef struct pjmedia_echo_state pjmedia_echo_state; /** * Echo cancellation options. */ typedef enum pjmedia_echo_flag { /** * Use any available backend echo canceller algorithm. This is * the default settings. This setting is mutually exclusive with * PJMEDIA_ECHO_SIMPLE and PJMEDIA_ECHO_SPEEX. */ PJMEDIA_ECHO_DEFAULT= 0, /** * Force to use Speex AEC as the backend echo canceller algorithm. * This setting is mutually exclusive with PJMEDIA_ECHO_SIMPLE. */ PJMEDIA_ECHO_SPEEX = 1, /** * If PJMEDIA_ECHO_SIMPLE flag is specified during echo canceller * creation, then a simple echo suppressor will be used instead of * an accoustic echo cancellation. This setting is mutually exclusive * with PJMEDIA_ECHO_SPEEX. */ PJMEDIA_ECHO_SIMPLE = 2, /** * For internal use. */ PJMEDIA_ECHO_ALGO_MASK = 15, /** * If PJMEDIA_ECHO_NO_LOCK flag is specified, no mutex will be created * for the echo canceller, but application will guarantee that echo * canceller will not be called by different threads at the same time. */ PJMEDIA_ECHO_NO_LOCK = 16 } pjmedia_echo_flag; /** * Create the echo canceller. * * @param pool Pool to allocate memory. * @param clock_rate Media clock rate/sampling rate. * @param samples_per_frame Number of samples per frame. * @param tail_ms Tail length, miliseconds. * @param latency_ms Total lacency introduced by playback and * recording device. Set to zero if the latency * is not known. * @param options Options. If PJMEDIA_ECHO_SIMPLE is specified, * then a simple echo suppressor implementation * will be used instead of an accoustic echo * cancellation. * See #pjmedia_echo_flag for other options. * @param p_echo Pointer to receive the Echo Canceller state. * * @return PJ_SUCCESS on success, or the appropriate status. */ PJ_DECL(pj_status_t) pjmedia_echo_create(pj_pool_t *pool, unsigned clock_rate, unsigned samples_per_frame, unsigned tail_ms, unsigned latency_ms, unsigned options, pjmedia_echo_state **p_echo ); /** * Create multi-channel the echo canceller. * * @param pool Pool to allocate memory. * @param clock_rate Media clock rate/sampling rate. * @param channel_count Number of channels. * @param samples_per_frame Number of samples per frame. * @param tail_ms Tail length, miliseconds. * @param latency_ms Total lacency introduced by playback and * recording device. Set to zero if the latency * is not known. * @param options Options. If PJMEDIA_ECHO_SIMPLE is specified, * then a simple echo suppressor implementation * will be used instead of an accoustic echo * cancellation. * See #pjmedia_echo_flag for other options. * @param p_echo Pointer to receive the Echo Canceller state. * * @return PJ_SUCCESS on success, or the appropriate status. */ PJ_DECL(pj_status_t) pjmedia_echo_create2(pj_pool_t *pool, unsigned clock_rate, unsigned channel_count, unsigned samples_per_frame, unsigned tail_ms, unsigned latency_ms, unsigned options, pjmedia_echo_state **p_echo ); /** * Destroy the Echo Canceller. * * @param echo The Echo Canceller. * * @return PJ_SUCCESS on success. */ PJ_DECL(pj_status_t) pjmedia_echo_destroy(pjmedia_echo_state *echo ); /** * Reset the echo canceller. * * @param echo The Echo Canceller. * * @return PJ_SUCCESS on success. */ PJ_DECL(pj_status_t) pjmedia_echo_reset(pjmedia_echo_state *echo ); /** * Let the Echo Canceller know that a frame has been played to the speaker. * The Echo Canceller will keep the frame in its internal buffer, to be used * when cancelling the echo with #pjmedia_echo_capture(). * * @param echo The Echo Canceller. * @param play_frm Sample buffer containing frame to be played * (or has been played) to the playback device. * The frame must contain exactly samples_per_frame * number of samples. * * @return PJ_SUCCESS on success. */ PJ_DECL(pj_status_t) pjmedia_echo_playback(pjmedia_echo_state *echo, pj_int16_t *play_frm ); /** * Let the Echo Canceller know that a frame has been captured from the * microphone. The Echo Canceller will cancel the echo from the captured * signal, using the internal buffer (supplied by #pjmedia_echo_playback()) * as the FES (Far End Speech) reference. * * @param echo The Echo Canceller. * @param rec_frm On input, it contains the input signal (captured * from microphone) which echo is to be removed. * Upon returning this function, this buffer contain * the processed signal with the echo removed. * The frame must contain exactly samples_per_frame * number of samples. * @param options Echo cancellation options, reserved for future use. * Put zero for now. * * @return PJ_SUCCESS on success. */ PJ_DECL(pj_status_t) pjmedia_echo_capture(pjmedia_echo_state *echo, pj_int16_t *rec_frm, unsigned options ); /** * Perform echo cancellation. * * @param echo The Echo Canceller. * @param rec_frm On input, it contains the input signal (captured * from microphone) which echo is to be removed. * Upon returning this function, this buffer contain * the processed signal with the echo removed. * @param play_frm Sample buffer containing frame to be played * (or has been played) to the playback device. * The frame must contain exactly samples_per_frame * number of samples. * @param options Echo cancellation options, reserved for future use. * Put zero for now. * @param reserved Reserved for future use, put NULL for now. * * @return PJ_SUCCESS on success. */ PJ_DECL(pj_status_t) pjmedia_echo_cancel( pjmedia_echo_state *echo, pj_int16_t *rec_frm, const pj_int16_t *play_frm, unsigned options, void *reserved ); PJ_END_DECL /** * @} */ #endif /* __PJMEDIA_ECHO_H__ */