Network Working Group D. Hoffman
Request for Comments: 2250 G. Fernando
Obsoletes: 2038 Sun Microsystems, Inc.
Category: Standards Track V. Goyal
Precept Software, Inc.
AT&T Labs - Research
RTP Payload Format for MPEG1/MPEG2 Video
Status of this Memo
This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.
Copyright (C) The Internet Society (1998). All Rights Reserved.
This memo describes a packetization scheme for MPEG video and audio
streams. The scheme proposed can be used to transport such a video
or audio flow over the transport protocols supported by RTP. Two
approaches are described. The first is designed to support maximum
interoperability with MPEG System environments. The second is
designed to provide maximum compatibility with other RTP-encapsulated
media streams and future conference control work of the IETF.
This memo is a revision of RFC 2038, an Internet standards track
protocol. In this revision, the packet loss resilience mechanisms in
Section 3.4 were extended to include additional picture header
information required for MPEG2. A new section on security
considerations for this payload type is added.
Hoffman, et. al. Standards Track [Page 1]RFC 2250 RTP Format for MPEG1/MPEG2 Video January 19981. Introduction
ISO/IEC JTC1/SC29 WG11 (also referred to as the MPEG committee) has
defined the MPEG1 standard (ISO/IEC 11172) and the MPEG2 standard
(ISO/IEC 13818). This memo describes a packetization scheme to
transport MPEG video and audio streams using the Real-time Transport
Protocol (RTP), version 2 [3, 4].
The MPEG1 specification is defined in three parts: System, Video and
Audio. It is designed primarily for CD-ROM-based applications, and
is optimized for approximately 1.5 Mbits/sec combined data rates. The
video and audio portions of the specification describe the basic
format of the video or audio stream. These formats define the
Elementary Streams (ES). The MPEG1 System specification defines an
encapsulation of the ES that contains Presentation Time Stamps (PTS),
Decoding Time Stamps and System Clock references, and performs
multiplexing of MPEG1 compressed video and audio ES's with user data.
The MPEG2 specification is structured in a similar way. However, it
hasn't been restricted only to CD-ROM applications. The MPEG2 System
specification defines two system stream formats: the MPEG2 Transport
Stream (MTS) and the MPEG2 Program Stream (MPS). The MTS is tailored
for communicating or storing one or more programs of MPEG2 compressed
data and also other data in relatively error-prone environments. The
MPS is tailored for relatively error-free environments.
We seek to achieve interoperability among 4 types of end-systems in
the following specification. The 4 types are:
1. Transmitting Interworking Unit (TIU)
Receives MPEG information from a native MTS system for
distribution over packet networks using a native RTP-based
system layer (such as an IP-based internetwork). Examples:
real-time encoder, MTS satellite link to Internet, video
server with MTS-encoded source material.
2. Receiving Interworking Unit (RIU)
Receives MPEG information in real time from an RTP-based
network for forwarding to a native MTS environment.
Examples: Internet-based video server to MTS-based cable
Hoffman, et. al. Standards Track [Page 2]RFC 2250 RTP Format for MPEG1/MPEG2 Video January 1998
3. Transmitting Internet End-System (TAES)
Transmits MPEG information generated or stored within the
internet end-system itself, or received from internet-based
computer networks. Example: video server.
4. Receiving Internet End-System (RAES)
Receives MPEG information over an RTP-based internet for