| /* $Id$ */ |
| /* |
| * Copyright (C) 2008-2011 Teluu Inc. (http://www.teluu.com) |
| * Copyright (C) 2003-2008 Benny Prijono <benny@prijono.org> |
| * |
| * 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 <pjmedia/types.h> |
| |
| |
| |
| /** |
| * @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, |
| |
| /** |
| * If PJMEDIA_ECHO_USE_SIMPLE_FIFO flag is specified, the delay buffer |
| * created for the echo canceller will use simple FIFO mechanism, i.e. |
| * without using WSOLA to expand and shrink audio samples. |
| */ |
| PJMEDIA_ECHO_USE_SIMPLE_FIFO = 32, |
| |
| /** |
| * If PJMEDIA_ECHO_USE_SW_ECHO flag is specified, software echo canceller |
| * will be used instead of device EC. |
| */ |
| PJMEDIA_ECHO_USE_SW_ECHO = 64 |
| |
| } 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__ */ |
| |