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 (C) The Internet Society (1998). All Rights Reserved.
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.
Internet-oriented multimedia applications reference multimedia
content via predefined mechanisms (e.g., ). 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 ) 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., , , ) 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  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 .
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