Internet Draft Hoschka draft-hoschka-rtp-mime-00.txt W3C/INRIA/MIT February 26, 1999 Expires: August 26, 1999 MIME Type Registration of RTP Payload Types STATUS OF THIS MEMO This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet- Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. ABSTRACT This document defines a procedure to register RTP Payload Types as audio or video MIME types. This is useful to identify the type of an RTP transmission in a text-based format or protocol. It also registers all RTP payload types defined in the document "RTP Profile for Audio and Video Conferences" (AVT profile) as MIME types. This is a rough draft. 1. Procedure For Registering MIME Types for RTP Payload Types Registering an RTP payload type as MIME type follows the same procedures as described in RFC2048. In the registration template (see Section 2.8 of RFC2048), the fact that the type can be transferred via RTP should be noted under "Encoding considerations". Depending on whether the type has already been registered for transfer with a non-RTP protocol (e.g. MIME mail or http) or not, several different cases can occur: a) Not yet registered as a MIME type Example Registration Form: ---------- To: ietf-types@iana.org Subject: Registration of MIME media type audio/XXX MIME media type name: audio MIME subtype name: XXX Required parameters: Optional parameters: Encoding considerations: This type can be transferred via RTP [RFCXXXX] only. Security considerations: none Interoperability considerations: none Published specification: RFCYYYY Applications which use this media type: foo-tools Additional information: none Person & email address to contact for further information: Dr. Foo foo-owner@foo.org Intended usage: COMMON Author/Change controller: Dr. Foo ----------- b) MIME type exists for a non-RTP protocol The encoding considerations of the existing type should be changed to indicate that the type can also be transferred via RTP. RTP-specific parameters can be added, and it must be clearly stated that these are only to be used when the media type is tranmitted via RTP transport. c) Update an existing MIME type for RTP to be used for a non-RTP protocol The encoding considerations of the existing type should be changed to indicate that the type can also be transferred via a non-RTP protocol (e.g. SMTP, HTTP). Non-RTP-specific parameters can be added, and it must be clearly stated that these are only to be used when the media type is tranmitted via a non-RTP transport. 2. Registrations for "Audio/Video Profile" In the following sections, all RTP payload types described in draft-ietf-profile-new-04.txt are registered as MIME types. The following fields of the registration template in RFC2048 have generic values for all of these registrations: Person & email address to contact for further information: See Section describing the respective type in draft-ietf-profile-new-04.txt. If no e-mail address is given, contact the author of draft-ietf-profile-new-04.txt Author/Change controller: See Section describing the respective type in draft-ietf-profile-new-04.txt 2.1 Audio Type Registrations Table X contains information for registering the RTP audio payload types defined in draft-ietf-profile-new-04.txt as MIME types. The MIME media type name of all types defined in this table is "audio". The first column gives the name of the encoding used in draft-ietf-profile-new-04.txt. The second column gives the name of the MIME subtype. The third column specifies whether the type has an optional (O, constant value in AVT profile) or mandatory (M, variable value in AVT profile) "samplingrate" parameter or not (-, N/A in AVT profile). The "sampling-rate" parameter is defined as for the "sampling rate" column in Table 1 in draft-ietf-profile-new-04.txt. It has an integer value. Example: sampling-rate=8000 The forth column specifies whether the type has an optional (O, constant value in AVT profile) "ms-per-frame" parameter or not (-, no value in AVT profile). The "ms-per-frame" parameter is defined as for the "ms/frame" column in Table 1 in draft-ietf-profile-new-04.txt. It has an integer value. Example: ms-per-frame=30 The fifth column specifies whether the type has an optional (O, constant value in AVT profile) or mandatory (M, no value in AVT profile) "ms-per-frame" parameter. The "default-ms-per-packet" parameter is defined as for the "default ms/packet" column in Table 1 in draft-ietf-profile-new-04.txt. It has an integer value. Example: default-ms-per-packet=30 @@ Section 1 should lay down general rules on when to register sampling-rate, ms-per-frame and default-ms-per-packet with an RTP audio type. name of MIME sampling default encoding subtype rate ms/frame ms/packet ____________________________________________________________________________ 1016 1016 O O O CN cn M - M DVI4 dvi4 M O O G722 g722 O - M G723 g723 O O O G726-16 g726 O - O G726-24 g726-24 O - O G726-32 g726-32 O - O G726-40 g726-40 O - O G727-16 g727-16 O - O G727-24 g727-24 O - O G727-32 g727-32 O - O G727-40 g727-40 O - O G728 g728 O O O G729 g720 O O O GSM gsm O O O L8 l8 M O M L16 l16 M O M LPC lpc O O O MPA mpa M O M PCMA pcma M O M PCMU pcmu M O M QCELP qcelp O O M SX7300P sx7300p O O O SX8300P sx8300p O O O SX9600P sx9600p O O O VDVI vdvi M O M 2.2 Audio types with addititional parameters [@@@ to be determined - do any of the types above need additional parameters specific to the respective type ?] 3. Video Type Registrations [@@@ analogous to audio] 4. Author's address Philipp Hoschka MIT-LCS INRIA W3C 545, Technology Square Route des Lucioles 2004 ph@w3.org Cambridge, MA 02139 06904, Sophia-Antipolis Cedex USA BP 93, France Tel:(+1) 617.258.0604 Tel:(+33) 4 92 38 79 84 Fax:(+1) 617.258.5999 Fax:(+33) 4 92 38 77 65 http://www.w3.org/people/hoschka 5. References @@@ to be supplied