Hi all,
Please find below an I-D for the proposed registration of MIME type
audio/rtp-vorbis. All comments most welcome.
Barry
<p>-----------8<-------------
Network Working Group Barry Short
Internet-Draft The Ogg Vorbis Community / OpenDrama
Expires: July 7, 2003 January 7, 2003
<p> The audio/rtp-vorbis MIME Type
draft-short-avt-rtp-vorbis-mime-00.txt
<p>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.
This internet draft will expire on July 7, 2003.
The key words "MUST", "MUST NOT", "REQUIRED",
"SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED",
"MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [1].
<p>Copyright Notice
Copyright (C) The Internet Society (2003). All Rights Reserved.
<p>Abstract
This document explains the need for a MIME subtype which identifies
a Vorbis audio payload to be used within a Realtime Transport
Protocol (RTP) bitstream.
This document also provides the necessary information to register
audio/rtp-vorbis as a MIME type.
<p><p><p><p><p>Short Expires
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<p>1. Introduction
The Vorbis Bitstream format [5] developed by Xiph.org is a
compressed audio format that uses pyschoacoustic compression
algorithms with highly optimized bit-allocation. It has been
developed as part of a larger project which aims to present a series
of multimedia content carrier bitstreams, which are to be freely
available to the computing community at large. These bitstreams are
created by software or hardware encoder-decoders (codecs).
For file based storage, Vorbis is generally encapsulated within the
Ogg bitstream format described in [2]. However, raw packets from the
Vorbis codecs can be used directly with transport mechanisms that
provide their own framing and packet-separation.
One such mechanism is the Real-time Transport Protocol (RTP),
described in [3]. A payload format for using Vorbis audio over RTP
is described in [4]. This document serves to register the
audio/rtp-vorbis MIME type, and is a companion document to [4].
<p><p>2. Registration Information:
<p> To: ietf-types@iana.org
Subject: Registration of MIME type audio/rtp-vorbis
Media MIME type name: audio
Media MIME subtype name: rtp-vorbis
Required Parameters: none
Optional Parameters: none
<p><p> Encoding Considerations:
The Vorbis audio data is always wrapped within and RTP bitstream
when transported with this MIME type.
Since the Vorbis data is already compressed as detailed above,
further lossless compression MAY be unnecessary. However, RTP
header compression MAY be used to reduce the packet size.
See [4] for further information on RTP encoding issues.
<p><p><p><p><p>Short Expires
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<p> Security Considerations:
The Vorbis format is highly specified [5] and so cannot contain
security violating code. It could be possible to exploit errors or
vulnerabilities in the decoder implementation, by abusing fields
with arbitrary code. It is the decoder's responsibility to ensure
that untrusted code is not executed.
Vorbis bitstreams are neither signed nor encrypted, so external
security systems should be added to ensure authenticity or
confidentiality where required.
Cryptographic authentication of incoming RTP and RTCP packets is
highly recommended. Without such protections, attackers could
corrupt the audio bitstream, potentially damaging speakers and
eardrums.
Further RTP security considerations are detailed in [3].
<p> Interoperability Consideration:
Conformance to the specification detailed in [4] ensures no
interoperability issues need arise.
<p> Published Specification:
See [4]
<p> Applications which use this media type:
Any application which uses the specification outlined in [4]
will be able to decode the bitestream.
<p> Additional Information:
Magic Numbers: none
File Extention: none
Macintosh File Type Code: none
Object Identifier(s) of OID(s): none
<p><p><p><p><p><p><p><p>Short
Expires July 7, 2003 [Page 3]
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<p> Person & Email address to contact for further information:
For questions about this proposal contact:
Barry Short <b.short@elec.gla.ac.uk>.
For technical questions about Vorbis see the mailing list of the
developer community <http://www.xiph.org/archives>
<p> Internet Usage: COMMON
<p> Author/Change Controller:
This document was written by Barry Short, changes of this document
will be handled by the author or a representative of the Vorbis
development community.
<p>3. Security Considerations:
Security considerations are discussed in the security considerations
clause in section 2 of this document.
<p>4. References
1. Key words for use in RFCs to Indicate Requirement Levels
(RFC 2119)
2. The Ogg encapsulation format,
Work in Progress, draft-pfeiffer-ogg-fileformat-00.txt
3. RTP: A Transport Protocol for Real-Time Applications, (RFC 1889)
4. RTP Payload Format for Vorbis Encoded Audio.
Work in Progress, draft-kerr-avt-vorbis-rtp-00.txt
5. libvorbis: Available from Xiph website, http://www.xiph.org
<p>5. Author's address
Barry Short
Centre for Music Technology
University of Glasgow
Glasgow
UK
G12 8LT
Phone: +44 141 330 5740
Email: b.short@elec.gla.ac.uk
<p><p><p><p>Short Expires July 7,
2003 [Page 4]
Internet-Draft draft-short-avt-rtp-vorbis-mime-00.txt January 2003
<p>6. Full Copyright Statement
Copyright (C) The Internet Society (2003). All Rights Reserved.
This document and translations of it may be copied and furnished to
others, and derivative works that comment on or otherwise explain it
or assist in its implementation may be prepared, copied, published
and distributed, in whole or in part, without restriction of any
kind, provided that the above copyright notice and this paragraph
are included on all such copies and derivative works. However, this
document itself may not be modified in any way, such as by removing
the copyright notice or references to the Internet Society or other
Internet organizations, except as needed for the purpose of
developing Internet standards in which case the procedures for
copyrights defined in the Internet Standards process must be
followed, or as required to translate it into languages other than
English.
The limited permissions granted above are perpetual and will not be
revoked by the Internet Society or its successors or assigns.
This document and the information contained herein is provided on an
"AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
<p>7. Acknowledgement
This document borrows from previous MIME type registrations,
Internet-Drafts and RFCs. Thanks also to the Vorbis community.
<p><p><p>Short Expires July 7, 2003
[Page 5]
--
Barry Short
Research Assistant
Centre for Music Technology
University of Glasgow
+44 (0)141 330 5740
B.Short@elec.gla.ac.uk
"If you can keep your head when all around are losing theirs,
perhaps you haven't quite grasped the gravity of the situation."
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