The Ogg Encapsulation Format Version 0
RFC 3533

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Network Working Group                                        S. Pfeiffer
Request for Comments: 3533                                         CSIRO
Category: Informational                                         May 2003

                 The Ogg Encapsulation Format Version 0

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 (2003).  All Rights Reserved.

Abstract

   This document describes the Ogg bitstream format version 0, which is
   a general, freely-available encapsulation format for media streams.
   It is able to encapsulate any kind and number of video and audio
   encoding formats as well as other data streams in a single bitstream.

Terminology

   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 BCP 14, RFC 2119 [2].

Table of Contents

   1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . .   2
   2. Definitions  . . . . . . . . . . . . . . . . . . . . . . . . .   2
   3. Requirements for a generic encapsulation format  . . . . . . .   3
   4. The Ogg bitstream format . . . . . . . . . . . . . . . . . . .   3
   5. The encapsulation process  . . . . . . . . . . . . . . . . . .   6
   6. The Ogg page format  . . . . . . . . . . . . . . . . . . . . .   9
   7. Security Considerations  . . . . . . . . . . . . . . . . . . .  11
   8. References . . . . . . . . . . . . . . . . . . . . . . . . . .  12
   A. Glossary of terms and abbreviations  . . . . . . . . . . . . .  13
   B. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . .  14
      Author's Address . . . . . . . . . . . . . . . . . . . . . . .  14
      Full Copyright Statement . . . . . . . . . . . . . . . . . . .  15

Pfeiffer                     Informational                      [Page 1]
RFC 3533                          OGG                           May 2003

1. Introduction

   The Ogg bitstream format has been developed as a part of a larger
   project aimed at creating a set of components for the coding and
   decoding of multimedia content (codecs) which are to be freely
   available and freely re-implementable, both in software and in
   hardware for the computing community at large, including the Internet
   community.  It is the intention of the Ogg developers represented by
   Xiph.Org that it be usable without intellectual property concerns.

   This document describes the Ogg bitstream format and how to use it to
   encapsulate one or several media bitstreams created by one or several
   encoders.  The Ogg transport bitstream is designed to provide
   framing, error protection and seeking structure for higher-level
   codec streams that consist of raw, unencapsulated data packets, such
   as the Vorbis audio codec or the upcoming Tarkin and Theora video
   codecs.  It is capable of interleaving different binary media and
   other time-continuous data streams that are prepared by an encoder as
   a sequence of data packets.  Ogg provides enough information to
   properly separate data back into such encoder created data packets at
   the original packet boundaries without relying on decoding to find
   packet boundaries.

   Please note that the MIME type application/ogg has been registered
   with the IANA [1].

2. Definitions

   For describing the Ogg encapsulation process, a set of terms will be
   used whose meaning needs to be well understood.  Therefore, some of
   the most fundamental terms are defined now before we start with the
   description of the requirements for a generic media stream
   encapsulation format, the process of encapsulation, and the concrete
   format of the Ogg bitstream.  See the Appendix for a more complete
   glossary.

   The result of an Ogg encapsulation is called the "Physical (Ogg)
   Bitstream".  It encapsulates one or several encoder-created
   bitstreams, which are called "Logical Bitstreams".  A logical
   bitstream, provided to the Ogg encapsulation process, has a
   structure, i.e., it is split up into a sequence of so-called
   "Packets".  The packets are created by the encoder of that logical
   bitstream and represent meaningful entities for that encoder only
   (e.g., an uncompressed stream may use video frames as packets).  They
   do not contain boundary information - strung together they appear to
   be streams of random bytes with no landmarks.

Pfeiffer                     Informational                      [Page 2]
RFC 3533                          OGG                           May 2003

   Please note that the term "packet" is not used in this document to
   signify entities for transport over a network.

3. Requirements for a generic encapsulation format

   The design idea behind Ogg was to provide a generic, linear media