TCP/IP Tutorial and Technical Overview - IBM Redbooks

Delay since last SR (DLSR)
Contains the delay between receiving the last SR packet
from the source SSRC_n and the sending of the current
exception report block in units of 1/65536 seconds.
21.3.6 Moving Picture Experts Group (MPEG) standards
MPEG is a standard for encoding and decoding video in a compressed format.
The latest version is MPEG-4.
It was jointly developed by the ITU-T Video Coding Experts Group (VCEG)
together with the ISO/IEC Moving Picture Experts Group (MPEG) as the product
of a collective partnership effort known as the Joint Video Team (JVT). ISO/IEC
MPPEG-4 and ITU-T H.264 are technically identical. The following list describes
the standards:
► MPEG-1: Initially designed as a video and audio compression standard.
Later, it became the standard for video CD. This standard included the MPEG
Audio Layer 3 (MP3) compression format.
► MPEG-2: Designed as the TV compression format for transport of video and
audio for broadcast-quality television. Used for over-the-air digital television
ATSC, DVB and ISDB, digital satellite TV services, digital cable television
signals, and (with slight modifications) for digital video disk (DVD).
► MPEG-3: Originally designed for HDTV. It was obsoleted because MPEG-2
was sufficient for HDTV.
► MPEG-4: The latest version of video compression with low-bit rate encoding
and security support. Additional higher efficiency video standards are
included for Advanced Simple Profile (ASP) and Advanced Video Coding
(AVC). AVC works well on a very wide variety of networks and systems (for
example, for broadcast, DVD storage, RTP/IP packet networks, and ITU-T
multimedia systems).
MPEC provides multipicture motion compensation using previously-encoded
pictures as references in a much more flexible way than in past standards,
allowing up to 32 reference pictures to be used in some cases (unlike in prior
standards, where the limit was typically one or two). In certain types of scenes,
for example, scenes with rapid repetitive flashing or back-and-forth scene cuts or
uncovered background areas, it allows a very significant reduction in bit rate.
It uses variable block-size motion compensation (VBSMC) with block sizes as
large as 16 by16 and as small as 4 by 4, enabling very precise segmentation of
moving regions.
Chapter 21. Internet Protocol Television 767