Page 213 - DCAP303_MULTIMEDIA_SYSTEMS

Unit 12: Image Format

• MPEG-4 was created to stream DVD quality video at lower data rates and smaller file sizes. notes
The MPEG-4 supports video/audio “objects”, 3D content, sprites, text and other media
types. The MPEG-4 has become extremely popular due to the ability to fit a two-hour movie
to a CD file retaining comparatively high quality.
• MPEG-7 describes multimedia content.
• MPEG-21 is supposed to become a standard as a multimedia framework.

The MPEG was established in 1988 by the initiative of Hiroshi Yasuda (Nippon
Telegraph and Telephone) and Leonardo Chiariglione.
12.5.1 standards

The MPEG standards consist of different Parts. Each part covers a certain aspect of the whole
specification. The standards also specify Profiles and Levels. Profiles are intended to define a set of
tools that are available, and Levels define the range of appropriate values for the properties associated
with them. Some of the approved MPEG standards were revised by later amendments and/or new
editions. The MPEG has standardized the following compression formats and ancillary standards:

• MpeG-1 (1993): Coding of moving pictures and associated audio for digital storage media
at up to about 1.5 Mbit/s (ISO/IEC 11172). The first MPEG compression standard for audio
and video. It is commonly limited to about 1.5 Mbit/s although the specification is capable
of much higher bit rates. It was basically designed to allow moving pictures and sound to be
encoded into the bitrate of a Compact Disc. It is used on Video CD, SVCD and can be used
for low-quality video on DVD Video. It was used in digital satellite/cable TV services before
MPEG-2 became widespread. To meet the low bit requirement, MPEG-1 down samples the
images, as well as uses picture rates of only 24–30 Hz, resulting in a moderate quality. It
includes the popular MPEG-1 Audio Layer III (MP3) audio compression format.
• MpeG-2 (1995): Generic coding of moving pictures and associated audio information (ISO/
IEC 13818). Transport, video and audio standards for broadcast-quality television. MPEG-2
standard was considerably broader in scope and of wider appeal – supporting interlacing
and high definition. The MPEG-2 is considered important because it has been chosen as
the compression scheme for over-the-air digital television ATSC, DVB and ISDB, digital
satellite TV services like Dish Network, digital cable television signals, SVCD and DVD
Video. It is also used on Blu-ray Discs, but these normally use MPEG-4 Part 10 or SMPTE
VC-1 for high-definition content.

• MpeG-3: MPEG-3 dealt with standardizing scalable and multi-resolution compression and
was intended for HDTV compression but was found to be redundant and was merged with
MPEG-2; as a result there is no MPEG-3 standard. The MPEG-3 is not to be confused with
MP3, which is MPEG-1 Audio Layer III.

• MpeG-4 (1998): Coding of audio-visual objects (ISO/IEC 14496) MPEG-4 uses further coding
tools with additional complexity to achieve higher compression factors than MPEG-2. In
addition to more efficient coding of video, MPEG-4 moves closer to computer graphics
applications. In more complex profiles, the MPEG-4 decoder effectively becomes a rendering
processor and the compressed bitstream describes three-dimensional shapes and surface
texture. The MPEG-4 supports Intellectual Property Management and Protection (IPMP),
which provides the facility to use proprietary technologies to manage and protect content
like digital rights management. It also supports MPEG-J, a fully programmatic solution
for creation of custom interactive multimedia applications (Java application environment
with a Java API) and many other features. Several new higher-efficiency video standards
(newer than MPEG-2 Video) are included, notably:

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