From 6754343f23d92368047f3030c60ef0296551ce67 Mon Sep 17 00:00:00 2001 From: Peter Saint-Andre Date: Mon, 30 Oct 2006 23:07:38 +0000 Subject: [PATCH] 0.6-pre2 git-svn-id: file:///home/ksmith/gitmigration/svn/xmpp/trunk@134 4b5297f7-1745-476d-ba37-a9c6900126ab --- xep-0167.xml | 94 ++++++++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 84 insertions(+), 10 deletions(-) diff --git a/xep-0167.xml b/xep-0167.xml index 6788d132..10875a64 100644 --- a/xep-0167.xml +++ b/xep-0167.xml @@ -10,7 +10,7 @@ This document defines a content description format for Jingle audio sessions. &LEGALNOTICE; 0167 - Experimental + Proposed Standards Track Standards JIG Council @@ -27,8 +27,8 @@ 0.6 2006-10-30 - psa -

Revised schema to allow child elements of the payload-type element; added Speex examples.

 + psa/se +

Specified how to include SDP parameters and codec-specific parameters; added Speex examples.

 0.5 @@ -91,8 +91,46 @@ -

A Jingle audio 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/> element specifies an encoding that can be used for the audio stream. In Jingle Audio, these encodings are used in the context of RTP. 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 'id' attribute is REQUIRED. The 'name' attribute is RECOMMENDED for static payload types, and REQUIRED for dynamic payload types. The 'clockrate' attribute is RECOMMENDED and should specify the sampling frequency in hertz. The 'channels' attribute is RECOMMENDED and should specify the number of channels; if omitted, it MUST be assumed to contain one channel.

-

The encodings SHOULD be provided in order of preference.

+

A Jingle audio 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/> element specifies an encoding that can be used for the audio stream. In Jingle Audio, these encodings are used in the context of RTP. 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 allowable attributes are as follows:

+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
AttributeDescriptionInclusion
channelsThe number of channels; if omitted, it MUST be assumed to contain one channelRECOMMENDED
clockrateThe sampling frequency in HertRECOMMENDED
idThe payload identifierREQUIRED
maxptimeMaximum packet time as specified in RFC 4566OPTIONAL
nameThe appropriate subtype of the audio MIME typeRECOMMENDED for static payload types, REQUIRED for dynamic payload types
ptimePacket time as specified in RFC 4566OPTIONAL
+

The encodings SHOULD be provided in order of preference.

@@ -111,7 +149,11 @@ ]]>

The <description/> element is intended to be a child of a &JINGLE; element as specified in XEP-0166.

-

Each <payload-type/> element MAY contain a child element that specifies more detailed information. For example, as described in draft-ietf-avt-rtp-speex, the "ptime", "sr", "ebw", "vbr", "eng", and "mode" parameters may be specified in relation to usage of the Speex See <http://www.speex.org/>. codec. XML representation of such parameters shall be provided in separate specifications or in a registry to be maintained by the XMPP Registrar.

+

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-speex This Internet-Draft has expired; see <http://www.watersprings.org/pub/id/draft-ietf-avt-rtp-speex-00.txt> for an archived version., the "ebw", "eng", "mode", "sr", and "vbr" parameters may be specified in relation to usage of the Speex See <http://www.speex.org/>. codec. Where such parameters are encoded via the "fmtp" SDP attribute, they shall be represented in Jingle via the following format:

+ + ]]> +

The parameter names are guaranteed to be unique, since &IANA; maintains a registry of SDP parameters (see <http://www.iana.org/assignments/sdp-parameters>).

If the payload type is static (payload-type IDs 0 through 95 inclusive), it MUST be mapped to a media field defined in RFC 4566: Session Description Protocol (SDP). The generic format for the media field is as follows:

@@ -135,6 +177,19 @@ m=audio 9999 RTP/AVP 13 m=audio 9999 RTP/AVP 96 a=rtpmap:96 SPEEX/16000 ]]> +

As noted, if additional parameters are to be specified, they shall be represented as attributes of the <payload-type/> element or of the child <parameter/> element, as in the following example.

+ + + + + ]]> +

If an entity supports the Jingle audio content description format, it MUST advertise that fact by returning a feature of "http://jabber.org/protocol/jingle/description/audio" in response to &xep0030; information requests.

@@ -308,24 +363,43 @@ a=rtpmap:96 SPEEX/16000 - - + + - - + + + + + + + + + + + + + + + + + + + + + ]]>