1 /* Copyright (C) Jean-Marc Valin */ 2 /** 3 @file speex_echo.h 4 @brief Echo cancellation 5 */ 6 /* 7 Redistribution and use in source and binary forms, with or without 8 modification, are permitted provided that the following conditions are 9 met: 10 11 1. Redistributions of source code must retain the above copyright notice, 12 this list of conditions and the following disclaimer. 13 14 2. Redistributions in binary form must reproduce the above copyright 15 notice, this list of conditions and the following disclaimer in the 16 documentation and/or other materials provided with the distribution. 17 18 3. The name of the author may not be used to endorse or promote products 19 derived from this software without specific prior written permission. 20 21 THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 22 IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 23 OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 24 DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, 25 INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 26 (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 27 SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 29 STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN 30 ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 31 POSSIBILITY OF SUCH DAMAGE. 32 */ 33 34 #ifndef SPEEX_ECHO_H 35 #define SPEEX_ECHO_H 36 37 #include "misc.h" 38 39 #ifdef __cplusplus 40 extern "C" { 41 #endif 42 43 /*struct drft_lookup;*/ 44 struct SpeexEchoState_; 45 46 typedef struct SpeexEchoState_ SpeexEchoState; 47 48 /** Creates a new echo canceller state */ 49 SpeexEchoState *speex_echo_state_init(int frame_size, int filter_length); 50 51 /** Destroys an echo canceller state */ 52 void speex_echo_state_destroy(SpeexEchoState *st); 53 54 /** Performs echo cancellation a frame */ 55 void speex_echo_cancel(SpeexEchoState *st, short *ref, short *echo, short *out, spx_int32_t *Y); 56 57 /** Reset the echo canceller state */ 58 void speex_echo_state_reset(SpeexEchoState *st); 59 60 #ifdef __cplusplus 61 } 62 #endif 63 64 #endif 65