/* $Id$ */ /* * Copyright (C) 2008-2011 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 and * PJMEDIA_ECHO_WEBRTC. */ 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 and PJMEDIA_ECHO_WEBRTC. */ PJMEDIA_ECHO_SIMPLE = 2, /** * Force to use WebRTC AEC as the backend echo canceller algorithm. * This setting is mutually exclusive with PJMEDIA_ECHO_SIMPLE and * PJMEDIA_ECHO_SPEEX. */ PJMEDIA_ECHO_WEBRTC = 3, /** * 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, /** * If PJMEDIA_ECHO_USE_NOISE_SUPPRESSOR flag is specified, the echo * canceller will also apply noise suppressor method to reduce noise. */ PJMEDIA_ECHO_USE_NOISE_SUPPRESSOR = 128, /** * Use default aggressiveness setting for the echo canceller algorithm. * This setting is mutually exclusive with the other aggressiveness * settings. */ PJMEDIA_ECHO_AGGRESSIVENESS_DEFAULT = 0, /** * Use conservative aggressiveness setting for the echo canceller * algorithm. This setting is mutually exclusive with the other * aggressiveness settings. */ PJMEDIA_ECHO_AGGRESSIVENESS_CONSERVATIVE = 0x100, /** * Use moderate aggressiveness setting for the echo canceller algorithm. * This setting is mutually exclusive with the other aggressiveness * settings. */ PJMEDIA_ECHO_AGGRESSIVENESS_MODERATE = 0x200, /** * Use aggressive aggressiveness setting for the echo canceller * algorithm. This setting is mutually exclusive with the other * aggressiveness settings. */ PJMEDIA_ECHO_AGGRESSIVENESS_AGGRESSIVE = 0x300, /** * For internal use. */ PJMEDIA_ECHO_AGGRESSIVENESS_MASK = 0xF00 } pjmedia_echo_flag; /** Statistic not specified. */ #define PJMEDIA_ECHO_STAT_NOT_SPECIFIED 999999 /** * Echo cancellation statistics. */ typedef struct pjmedia_echo_stat { /** * The name of the EC backend. * NULL if not specified. */ const char *name; /** * Echo delay median value (in ms). * PJMEDIA_ECHO_STAT_NOT_SPECIFIED if unavailable. */ int median; /** * Echo delay standard deviation (in ms). * PJMEDIA_ECHO_STAT_NOT_SPECIFIED if unavailable. */ int std; /** * Fraction of poor delay. Value between 0 to 1. The closer to 1, * the poorer the EC quality. * PJMEDIA_ECHO_STAT_NOT_SPECIFIED if unavailable. */ float frac_delay; /** * Learning still in progress? PJ_TRUE if yes, false if done. * PJMEDIA_ECHO_STAT_NOT_SPECIFIED if unavailable. */ unsigned learning; /** * Learning duration (in ms). * PJMEDIA_ECHO_STAT_NOT_SPECIFIED if unavailable. */ unsigned duration; /** * Detected echo tail length (in ms). * PJMEDIA_ECHO_STAT_NOT_SPECIFIED if unavailable. */ unsigned tail; /** * Minimum scaling factor (in ms). * PJMEDIA_ECHO_STAT_NOT_SPECIFIED if unavailable. */ int min_factor; /** * Average scaling factor (in ms). * PJMEDIA_ECHO_STAT_NOT_SPECIFIED if unavailable. */ int avg_factor; /** * Text describing the statistic. */ pj_str_t stat_info; /** * Internal buffer. */ char buf_[128]; } pjmedia_echo_stat; /** * Initialize Echo cancellation stat. * * @param stat The statistic to be initialized. */ PJ_DECL(void) pjmedia_echo_stat_default(pjmedia_echo_stat *stat); /** * 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 ); /** * Get the echo canceller statistics. * * @param echo The Echo Canceller. * @param p_stat Pointer to receive the stat. * * @return PJ_SUCCESS on success. */ PJ_DECL(pj_status_t) pjmedia_echo_get_stat(pjmedia_echo_state *echo, pjmedia_echo_stat *p_stat); /** * 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__ */