RFC 3533 (rfc3533) - Page 2 of 15
The Ogg Encapsulation Format Version 0
Alternative Format: Original Text Document
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