D-Modem/pjproject-2.11.1/pjmedia/include/pjmedia-codec/bcg729.h
2021-10-29 14:41:03 -04:00

121 lines
3.6 KiB
C

/* $Id$ */
/*
* Copyright (C) 2017 Teluu Inc. (http://www.teluu.com)
*
* 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_CODEC_BCG729_H__
#define __PJMEDIA_CODEC_BCG729_H__
/**
* @file bcg729.h
* @brief BCG729 codec.
*/
#include <pjmedia-codec/types.h>
/**
* @defgroup PJMED_BCG729 BCG729 Codec
* @ingroup PJMEDIA_CODEC_CODECS
* @brief Implementation of BCG729 codecs.
* @{
*
* This section describes functions to initialize and register BCG729 codec
* factory to the codec manager. After the codec factory has been registered,
* application can use @ref PJMEDIA_CODEC API to manipulate the codec.
*
* This codec factory contains G.729 codec.
*
* \section pjmedia_codec_bcg729 BCG729
*
* BCG729 is compliant with ITU-T G.729 and Annexes A, B specifications.
*
* BCGG729 supports 16-bit PCM audio signal with sampling rate 8000Hz,
* frame length 10ms, and resulting in bitrate 8000bps.
*
* \subsection codec_setting Codec Settings
*
* General codec settings for this codec such as VAD and PLC can be
* manipulated through the <tt>setting</tt> field in #pjmedia_codec_param.
* Please see the documentation of #pjmedia_codec_param for more info.
*
* Note that G.729 VAD status should be signalled in SDP, see more
* description below.
*
* \subsubsection annexb Annex B
*
* The capability of VAD/DTX is specified in Annex B.
*
* By default, Annex B is enabled. This default setting of Annex B can
* be modified using #pjmedia_codec_mgr_set_default_param().
*
* In #pjmedia_codec_param, Annex B is configured via VAD setting and
* format parameter "annexb" in the SDP "a=fmtp" attribute in
* decoding fmtp field. Valid values are "yes" and "no",
* the implementation default is "yes". When this parameter is omitted
* in the SDP, the value will be "yes" (RFC 4856 Section 2.1.9).
*
* Here is an example of modifying default setting of Annex B to
* be disabled using #pjmedia_codec_mgr_set_default_param():
\code
pjmedia_codec_param param;
pjmedia_codec_mgr_get_default_param(.., &param);
...
// Set VAD
param.setting.vad = 0;
// Set SDP format parameter
param.setting.dec_fmtp.cnt = 1;
param.setting.dec_fmtp.param[0].name = pj_str("annexb");
param.setting.dec_fmtp.param[0].val = pj_str("no");
...
pjmedia_codec_mgr_set_default_param(.., &param);
\endcode
*
* \note
* The difference of Annex B status in SDP offer/answer may be considered as
* incompatible codec in SDP negotiation.
*
*/
PJ_BEGIN_DECL
/**
* Initialize and register BCG729 codec factory to pjmedia endpoint.
*
* @param endpt The pjmedia endpoint.
*
* @return PJ_SUCCESS on success.
*/
PJ_DECL(pj_status_t) pjmedia_codec_bcg729_init(pjmedia_endpt *endpt);
/**
* Unregister BCG729 codec factory from pjmedia endpoint and deinitialize
* the BCG729 codec library.
*
* @return PJ_SUCCESS on success.
*/
PJ_DECL(pj_status_t) pjmedia_codec_bcg729_deinit(void);
PJ_END_DECL
/**
* @}
*/
#endif /* __PJMEDIA_CODEC_BCG729_H__ */