1 /* $Id$ */ 2 /* 3 * Copyright (C) 2008-2011 Teluu Inc. (http://www.teluu.com) 4 * Copyright (C) 2003-2008 Benny Prijono <benny@prijono.org> 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation; either version 2 of the License, or 9 * (at your option) any later version. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program; if not, write to the Free Software 18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 19 */ 20 #ifndef __PJMEDIA_PLC_H__ 21 #define __PJMEDIA_PLC_H__ 22 23 24 /** 25 * @file plc.h 26 * @brief Packet Lost Concealment (PLC) API. 27 */ 28 #include <pjmedia/types.h> 29 30 /** 31 * @defgroup PJMED_PLC Packet Lost Concealment (PLC) 32 * @ingroup PJMEDIA_FRAME_OP 33 * @brief Packet lost compensation algorithm 34 * @{ 35 * 36 * This section describes PJMEDIA's implementation of Packet Lost 37 * Concealment algorithm. This algorithm is used to implement PLC for 38 * codecs that do not have built-in support for one (e.g. G.711 or GSM 39 * codecs). 40 * 41 * The PLC algorithm (either built-in or external) is embedded in 42 * PJMEDIA codec instance, and application can conceal lost frames 43 * by calling <b><tt>recover()</tt></b> member of the codec's member 44 * operation (#pjmedia_codec_op). 45 * 46 * See also @ref plc_codec for more info. 47 */ 48 49 50 PJ_BEGIN_DECL 51 52 53 /** 54 * Opaque declaration for PLC. 55 */ 56 typedef struct pjmedia_plc pjmedia_plc; 57 58 59 60 /** 61 * Create PLC session. This function will select the PLC algorithm to 62 * use based on the arguments. 63 * 64 * @param pool Pool to allocate memory for the PLC. 65 * @param clock_rate Media sampling rate. 66 * @param samples_per_frame Number of samples per frame. 67 * @param options Must be zero for now. 68 * @param p_plc Pointer to receive the PLC instance. 69 * 70 * @return PJ_SUCCESS on success. 71 */ 72 PJ_DECL(pj_status_t) pjmedia_plc_create( pj_pool_t *pool, 73 unsigned clock_rate, 74 unsigned samples_per_frame, 75 unsigned options, 76 pjmedia_plc **p_plc); 77 78 79 /** 80 * Save a good frame to PLC. 81 * 82 * @param plc The PLC session. 83 * @param frame The good frame to be stored to PLC. This frame 84 * must have the same length as the configured 85 * samples per frame. 86 * 87 * @return PJ_SUCCESS on success. 88 */ 89 PJ_DECL(pj_status_t) pjmedia_plc_save( pjmedia_plc *plc, 90 pj_int16_t *frame ); 91 92 93 /** 94 * Generate a replacement for lost frame. 95 * 96 * @param plc The PLC session. 97 * @param frame Buffer to receive the generated frame. This buffer 98 * must be able to store the frame. 99 * 100 * @return PJ_SUCCESS on success. 101 */ 102 PJ_DECL(pj_status_t) pjmedia_plc_generate( pjmedia_plc *plc, 103 pj_int16_t *frame ); 104 105 106 107 108 PJ_END_DECL 109 110 /** 111 * @} 112 */ 113 114 #endif /* __PJMEDIA_PLC_H__ */ 115 116