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Diffstat (limited to 'pjmedia/include/pjmedia-codec/ipp_codecs.h')
| -rw-r--r-- | pjmedia/include/pjmedia-codec/ipp_codecs.h | 255 |
1 files changed, 252 insertions, 3 deletions
diff --git a/pjmedia/include/pjmedia-codec/ipp_codecs.h b/pjmedia/include/pjmedia-codec/ipp_codecs.h index 16459b3b..98eb8a87 100644 --- a/pjmedia/include/pjmedia-codec/ipp_codecs.h +++ b/pjmedia/include/pjmedia-codec/ipp_codecs.h @@ -33,11 +33,260 @@ * @brief Implementation of IPP codecs * @{ * - * This section describes functions to register and register IPP codec + * This section describes functions to initialize and register IPP 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 various codecs, e.g: G.729, G.723.1, G.726, - * G.728, G.722.1, AMR. + * + * This codec factory contains various codecs, i.e: G.729, G.723.1, G.726, + * G.728, G.722.1, AMR, and AMR-WB. + * + * + * \section pjmedia_codec_ipp_g729 IPP G.729 + * + * IPP G.729 is compliant with ITU-T G.729 and Annexes A, B, C, C+, D, + * E, I specifications. However, currently the pjmedia implementation is + * using Annexes A and B only. + * + * IPP G.729 supports 16-bit PCM audio signal with sampling rate 8000Hz, + * frame length 10ms, and resulting in bitrate 8000bps (annexes D and E + * introduce bitrates 6400bps and 11800bps). + * + * \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_ipp_g7231 IPP G.723.1 + * + * IPP G.723.1 speech codec is compliant with ITU-T G.723.1 and Annex A + * specifications. + * + * IPP G.723.1 supports 16-bit PCM audio signal with sampling rate 8000Hz, + * frame length 30ms, and resulting in bitrates 5300bps and 6300bps. + * + * By default, pjmedia implementation uses encoding bitrate of 6300bps. + * The bitrate is signalled in-band in G.723.1 frames and interoperable. + * + * \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. + * + * + * \section pjmedia_codec_ipp_g726 IPP G.726 + * + * IPP G.726 is compliant with ITU-T G.726 and G.726 Annex A specifications. + * + * IPP G.726 supports 16-bit PCM audio signal with sampling rate 8000Hz, + * 10ms frame length and producing 16kbps, 24kbps, 32kbps, 48kbps bitrates. + * The bitrate is specified explicitly in its encoding name, i.e: G726-16, + * G726-24, G726-32, G726-48. + * + * \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. + * + * + * \section pjmedia_codec_ipp_g728 IPP G.728 + * + * IPP G.728 is compliant with ITU-T G.728 with I, G, H Appendixes + * specifications for Low-Delay CELP coder. + * + * IPP G.728 supports 16-bit PCM audio signal with sampling rate 8000Hz, + * 20ms frame length and producing 9.6kbps, 12.8kbps, and 16kbps bitrates. + * + * The pjmedia implementation currently uses 16kbps bitrate only. + * + * \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. + * + * + * \section pjmedia_codec_ipp_g7221 IPP G.722.1 + * + * The pjmedia implementation of IPP G.722.1 supports 16-bit PCM audio + * signal with sampling rate 16000Hz, 20ms frame length and producing + * 16kbps, 24kbps, and 32kbps bitrates. + * + * \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 + * + * The codec implementation supports only standard bitrates, i.e: + * 24kbps and 32kbps. Both are enabled by default. + * + * \remark + * There is a flaw in the codec manager as currently it could not + * differentiate G.722.1 codecs by bitrates, hence invoking + * #pjmedia_codec_mgr_set_default_param() may only affect a G.722.1 codec + * with the highest priority (or first index found in codec enumeration + * when they have same priority) and invoking + * #pjmedia_codec_mgr_set_codec_priority() will set priority of all G.722.1 + * codecs with sampling rate as specified. + * + * + * \section pjmedia_codec_ipp_amr IPP AMR + * + * The IPP AMR is compliant with GSM06.90-94 specifications for GSM Adaptive + * Multi-Rate codec. + * + * 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_ipp_amrwb IPP AMR-WB + * + * The IPP AMR-WB is compliant with 3GPP TS 26.190-192, 194, 201 + * specifications for Adaptive Multi-Rate WideBand codec. + * + * IPP AMR-WB supports 16-bit PCM audio signal with sampling rate 16000Hz, + * 20ms frame length and producing various bitrates. Valid bitrates could be + * seen in #pjmedia_codec_amrwb_bitrates. The pjmedia implementation default + * bitrate is 15850bps. + * + * \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 15850bps. 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. + * + * \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. */ PJ_BEGIN_DECL |