WAVE and AVI Codec Registries
RFC 2361
Document | Type |
RFC - Informational
(June 1998; Errata)
Was draft-fleischman-codec-subtree (individual)
|
|
---|---|---|---|
Last updated | 2013-03-02 | ||
Stream | Legacy | ||
Formats | plain text pdf html bibtex | ||
Stream | Legacy state | (None) | |
Consensus Boilerplate | Unknown | ||
RFC Editor Note | (None) | ||
IESG | IESG state | RFC 2361 (Informational) | |
Telechat date | |||
Responsible AD | (None) | ||
Send notices to | (None) |
Network Working Group E. Fleischman Request for Comments: 2361 Microsoft Corporation Category: Informational June 1998 WAVE and AVI Codec Registries Status of this Memo This memo provides information for the Internet community. It does not specify an Internet standard of any kind. Distribution of this memo is unlimited. Copyright Notice Copyright (C) The Internet Society (1998). All Rights Reserved. Abstract Internet applications may reference specific codecs within the WAVE and AVI registries as follows: * video/vnd.avi; codec=XXX identifies a specific video codec (i.e., XXX) within the AVI Registry. * audio/vnd.wave; codec=YYY identifies a specific audio codec (i.e., YYY) within the WAVE Registry. Appendix A and Appendix B provides an authoritative reference for the interpretation of the required "codec" parameter. That is, the current set of audio codecs that are registered within the WAVE Registry are enumerated in Appendix A. Appendix B enumerates the current set of video codecs that have been registered to date within the AVI Registry. 1 Introduction Internet-oriented multimedia applications reference multimedia content via predefined mechanisms (e.g., [2]). In the general case, this content was created primarily for the use of these Internet- oriented applications. Unfortunately, this Internet-oriented multimedia content represents a small minority of the total amount of multimedia content that has been created to date. For this reason, a growing interest is forming in establishing mechanisms by which the repertoire of multimedia content available to Internet-oriented applications(e.g., for RTSP [3]) may be greatly extended to include multimedia content that has been created outside of distinctly Internet contexts. For this to occur, a mechanism must Fleischman Informational [Page 1] RFC 2361 WAVE and AVI Codec Registries June 1998 be created for Internet protocols (e.g., [1], [3], [4]) to be able to identify the codecs by which this so-called "traditional" multimedia content has been encoded. Unfortunately, several distinct encoding systems exist for traditional multimedia content. Each system has its own registry to ensure unique and stable codec identifications within that system. Perhaps the best known of these registries are Microsoft (for WAVE and AVI content) and Apple (for QuickTime content). The purpose of this paper is to establish a mechanism by which codecs registered within Microsoft's WAVE and AVI Registries may be referenced within the IANA Namespace by Internet applications. 2 References to Registries within the IANA Vendor Tree Reference [7] specifies that the IANA Namespace encompasses several trees. Discussions within the IETF-Types mailing list concluded that the most appropriate tree in which to reference codecs, which had already been registered by non-IANA Registries, is the Vendor Tree. As a result, the non-IANA registry is identified within the IANA Vendor tree by vnd.RegistryName. A specific codec, which has been registered within that registry, is identified by a required codec parameter as specified by Section 2.2.3 of [7]. 3 WAVE and AVI Registries Both the WAVE and AVI Registries are historic databases that have been maintained by Microsoft as a free service. The Registries sought to assist developers of WAVE and AVI content and to standardize WAVE and AVI content by 1) avoiding conflict and/or duplication with current definitions, and 2) providing the registered information in a standard document and format that is publicly available. The historic nature of these databases implies that unless the original registrants informed the registrar of a change of status (e.g., company acquired, new contact, new location, new phone), the contact information has generally not been updated from the originally registered values. Audio codecs within the WAVE Registry are identified by WAVE Format IDs. The (audio) WAVE Format ID is officially known as "WAVE form Registration Number". The WAVE Format ID is a hexadecimal integer value. These codecs may be referenced within the IANA namespace as Fleischman Informational [Page 2] RFC 2361 WAVE and AVI Codec Registries June 1998 "audio/vnd.wave; codec=XXX", where XXX represents a valid WAVE Format ID (e.g., the WAVE Format ID of "123" is referenced within the IANA namespace by "audio/vnd.wave; codec=123"). Video codecs within the AVI Registry are identified by AVI Codec IDs. The AVI Codec ID value is a FourCC encoding. A FourCC is 32-bits long and represents a (case-sensitive) four-character (i.e., ASCII) codeShow full document text