| /* $Id$ */ |
| /* |
| * 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_CODECS_PASSTHROUGH_H__ |
| #define __PJMEDIA_CODECS_PASSTHROUGH_H__ |
| |
| /** |
| * @file pjmedia-codec/passthrough.h |
| * @brief Passthrough codecs. |
| */ |
| |
| #include <pjmedia-codec/types.h> |
| |
| /** |
| * @defgroup PJMED_PASSTHROUGH_CODEC Passthrough Codecs |
| * @ingroup PJMEDIA_CODEC_CODECS |
| * @brief Implementation of passthrough codecs |
| * @{ |
| * |
| * This section describes functions to initialize and register passthrough |
| * codecs factory to the codec manager. After the codec factory has been |
| * registered, application can use @ref PJMEDIA_CODEC API to manipulate |
| * the codec. |
| * |
| * Passthrough codecs are codecs wrapper that does NOT perform encoding |
| * or decoding, it just PACK and PARSE encoded audio data from/into RTP |
| * payload. This will accomodate pjmedia ports which work with encoded |
| * audio data, e.g: encoded audio files, sound device with capability |
| * of playing/recording encoded audio data. |
| * |
| * This codec factory contains various codecs, i.e: G.729, iLBC, |
| * AMR, and G.711. |
| * |
| * |
| * \section pjmedia_codec_passthrough_g729 Passthrough G.729 |
| * |
| * G.729 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(.., ¶m); |
| ... |
| // 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(.., ¶m); |
| \endcode |
| * |
| * \note |
| * The difference of Annex B status in SDP offer/answer may be considered as |
| * incompatible codec in SDP negotiation. |
| * |
| * |
| * \section pjmedia_codec_passthrough_ilbc Passthrough iLBC |
| * |
| * The iLBC codec is developed by Global IP Solutions (GIPS), formerly |
| * Global IP Sound. The iLBC offers low bitrate and graceful audio quality |
| * degradation on frame losses. |
| * |
| * The iLBC codec supports 16-bit PCM audio signal with sampling rate of |
| * 8000Hz operating at two modes: 20ms and 30ms frame length modes, resulting |
| * in bitrates of 15.2kbps for 20ms mode and 13.33kbps for 30ms mode. |
| * |
| * \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. |
| * |
| * \subsubsection mode Mode |
| * |
| * The default mode should be set upon initialization, see |
| * #pjmedia_codec_passthrough_init2(). After the codec is initialized, the |
| * default mode can be modified using #pjmedia_codec_mgr_set_default_param(). |
| * |
| * In #pjmedia_codec_param, iLBC mode can be set by specifying SDP |
| * format parameter "mode" in the SDP "a=fmtp" attribute for decoding |
| * direction. Valid values are "20" and "30" (for 20ms and 30ms mode |
| * respectively). |
| * |
| * Here is an example to set up #pjmedia_codec_param to use mode 20ms: |
| * \code |
| pjmedia_codec_param param; |
| ... |
| // setting iLBC mode in SDP |
| param.setting.dec_fmtp.cnt = 1; |
| param.setting.dec_fmtp.param[0].name = pj_str("mode"); |
| param.setting.dec_fmtp.param[0].val = pj_str("20"); |
| ... |
| \endcode |
| * |
| * |
| * \section pjmedia_codec_passthrough_amr Passthrough AMR |
| * |
| * IPP AMR supports 16-bit PCM audio signal with sampling rate 8000Hz, |
| * 20ms frame length and producing various bitrates that ranges from 4.75kbps |
| * to 12.2kbps. |
| * |
| * \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. |
| * |
| * \subsubsection bitrate Bitrate |
| * |
| * By default, encoding bitrate is 7400bps. This default setting can be |
| * modified using #pjmedia_codec_mgr_set_default_param() by specifying |
| * prefered AMR bitrate in field <tt>info::avg_bps</tt> of |
| * #pjmedia_codec_param. Valid bitrates could be seen in |
| * #pjmedia_codec_amrnb_bitrates. |
| * |
| * \subsubsection payload_format Payload Format |
| * |
| * There are two AMR payload format types, bandwidth-efficient and |
| * octet-aligned. Default setting is using octet-aligned. This default payload |
| * format can be modified using #pjmedia_codec_mgr_set_default_param(). |
| * |
| * In #pjmedia_codec_param, payload format can be set by specifying SDP |
| * format parameters "octet-align" in the SDP "a=fmtp" attribute for |
| * decoding direction. Valid values are "0" (for bandwidth efficient mode) |
| * and "1" (for octet-aligned mode). |
| * |
| * \subsubsection mode_set Mode-Set |
| * |
| * Mode-set is used for restricting AMR modes in decoding direction. |
| * |
| * By default, no mode-set restriction applied. This default setting can be |
| * be modified using #pjmedia_codec_mgr_set_default_param(). |
| * |
| * In #pjmedia_codec_param, mode-set could be specified via format parameters |
| * "mode-set" in the SDP "a=fmtp" attribute for decoding direction. Valid |
| * value is a comma separated list of modes from the set 0 - 7, e.g: |
| * "4,5,6,7". When this parameter is omitted, no mode-set restrictions applied. |
| * |
| * Here is an example of modifying AMR default codec param: |
| \code |
| pjmedia_codec_param param; |
| |
| pjmedia_codec_mgr_get_default_param(.., ¶m); |
| ... |
| // set default encoding bitrate to the highest 12.2kbps |
| param.info.avg_bps = 12200; |
| |
| // restrict decoding bitrate to 10.2kbps and 12.2kbps only |
| param.setting.dec_fmtp.param[0].name = pj_str("mode-set"); |
| param.setting.dec_fmtp.param[0].val = pj_str("6,7"); |
| |
| // also set to use bandwidth-efficient payload format |
| param.setting.dec_fmtp.param[1].name = pj_str("octet-align"); |
| param.setting.dec_fmtp.param[1].val = pj_str("0"); |
| |
| param.setting.dec_fmtp.cnt = 2; |
| ... |
| pjmedia_codec_mgr_set_default_param(.., ¶m); |
| \endcode |
| * |
| * |
| * \section pjmedia_codec_passthrough_g711 Passthrough G.711 |
| * |
| * The G.711 is an ultra low complexity codecs and in trade-off it results |
| * in high bitrate, i.e: 64kbps for 16-bit PCM with sampling rate 8000Hz. |
| * |
| * The factory contains two main compression algorithms, PCMU/u-Law and |
| * PCMA/A-Law. |
| * |
| * \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. |
| */ |
| |
| PJ_BEGIN_DECL |
| |
| |
| /** |
| * Codec passthrough configuration settings. |
| */ |
| typedef struct pjmedia_codec_passthrough_setting |
| { |
| unsigned fmt_cnt; /**< Number of encoding formats |
| to be enabled. */ |
| pjmedia_format *fmts; /**< Encoding formats to be |
| enabled. */ |
| unsigned ilbc_mode; /**< iLBC default mode. */ |
| } pjmedia_codec_passthrough_setting; |
| |
| |
| /** |
| * Initialize and register passthrough codecs factory to pjmedia endpoint, |
| * all supported encoding formats will be enabled. |
| * |
| * @param endpt The pjmedia endpoint. |
| * |
| * @return PJ_SUCCESS on success. |
| */ |
| PJ_DECL(pj_status_t) pjmedia_codec_passthrough_init( pjmedia_endpt *endpt ); |
| |
| |
| /** |
| * Initialize and register passthrough codecs factory to pjmedia endpoint |
| * with only specified encoding formats enabled. |
| * |
| * @param endpt The pjmedia endpoint. |
| * @param setting The settings. |
| * |
| * @return PJ_SUCCESS on success. |
| */ |
| PJ_DECL(pj_status_t) pjmedia_codec_passthrough_init2( |
| pjmedia_endpt *endpt, |
| const pjmedia_codec_passthrough_setting *setting); |
| |
| |
| /** |
| * Unregister passthrough codecs factory from pjmedia endpoint. |
| * |
| * @return PJ_SUCCESS on success. |
| */ |
| PJ_DECL(pj_status_t) pjmedia_codec_passthrough_deinit(void); |
| |
| |
| PJ_END_DECL |
| |
| |
| /** |
| * @} |
| */ |
| |
| #endif /* __PJMEDIA_CODECS_PASSTHROUGH_H__ */ |
| |