DigitalVideoAndHDTVAlgorithmsAndInterfaces.pdf

Many MPEG terms – such as
frame, picture, and macroblock –
can refer to elements of the
source video, to the corresponding
elements in the coded
bitstream, or to the corresponding
elements in the reconstructed
video. It is generally clear
from context which is meant.
Symes, Peter, Video Compression
Demystified (New York: McGraw-
Hill, 2000).
MPEG-2
The MPEG-2 effort was initiated to extend MPEG-1 to
interlaced scanning, to larger pictures, and to data rates
much higher than 1.5 Mb/s. MPEG-2 is now widely
deployed for the distribution of digital television,
including standard-definition television (SDTV), DVD,
and high-definition television (HDTV). MPEG-2 is
defined by a series of standards from ISO/IEC.
MPEG-2 accommodates both progressive and interlaced
material. A video frame can be coded directly as
a frame-structured picture. Alternatively, a video frame
(typically originated from an interlaced source) may be
coded as a pair of field-structured pictures – a top-field
picture and a bottom-field picture. The two fields are
time-offset by half the frame time, and are intended for
interlaced display. Field pictures always come in pairs
having opposite parity (top/bottom). Both pictures in
a field pair have the same picture coding type (I, P, or
B), except that an I-field may be followed by a P-field
(in which case the pair is treated as an I-frame).
While the MPEG-2 work was underway, an MPEG-3
effort was launched to address HDTV. The MPEG-3
committee concluded early on that MPEG-2, at high
data rate, would accommodate HDTV. Consequently,
the MPEG-3 effort was abandoned. MPEG-4, MPEG-7,
and MPEG-21 are underway; the numbers have no
plan. MPEG-4 is concerned with coding at very low bit
rates. MPEG-7, titled Multimedia Content Description
Interface, will standardize description of various types
of multimedia information (metadata). MPEG-21 seeks
to establish an open framework for multimedia delivery
and consumption, thereby enabling use of multimedia
resources across a wide range of networks and devices.”
In my estimation, none of MPEGs 4, 7, or 21 are relevant
to handling studio- or distribution-quality video
signals.
I will detail JPEG and motion-JPEG (M-JPEG) compression
on page 447, DV compression on page 461, and
MPEG-2 video compression on page 473. Video and
audio compression technology is detailed in the book
by Peter Symes cited in the margin.
126 DIGITAL VIDEO AND HDTV ALGORITHMS AND INTERFACES