More completely specified how to include SDP parameters and codec-specific parameters (same approach as in XEP-0167); added and corrected Theora examples.
A Jingle video session is described by one or more encodings contained within a wrapper &DESCRIPTION; element. In the language of RFC 4566 these encodings are payload-types; therefore, each <payload-type/> child element specifies an encoding that can be used for the video stream. Such encodings are often used in the context of the Real-time Transfer Protocol (RTP; see RFC 3550) but may be used in other contexts as well. The most common encodings for the Audio/Video Profile (AVP) of RTP are listed in &rfc3551; (these "static" types are reserved from payload ID 0 through payload ID 95), although other encodings are allowed (these "dynamic" types use payload IDs 96 to 127) in accordance with the dynamic assignment rules described in Section 3 of RFC 3551. The &PAYLOADTYPE; element's 'id' attribute is REQUIRED and its 'name' attribute is RECOMMENDED. The encodings SHOULD be provided in order of preference.
The &DESCRIPTION; element is intended to be a child of a &JINGLE; element as specified in XEP-0166.
+The &DESCRIPTION; element is intended to be a child of a &CONTENT; element as specified in XEP-0166.
The defined attributes of the &PAYLOADTYPE; element are as follows:
positiveInteger |
Each <payload-type/> element MAY contain one or more child elements that specify particular parameters related to the payload. For example, as described in draft-ietf-avt-rtp-theora
+ ]]>
+ Note: The parameter names are effectively guaranteed to be unique, since &IANA; maintains a registry of SDP parameters (see <http://www.iana.org/assignments/sdp-parameters>).
As noted, if additional parameters are to be specified, they shall be represented as attributes of the <payload-type/> element of the child <parameter/> element, as in the following example.
Support for the Theora codec
Support for the Theora codec is RECOMMENDED.