MPEG-4 is a convergence of
MPEG-1, MPEG-2, etc. It incorporates a wide range of new technologies for video
compression … such as custom semiconductors and increase processing-power
advancements. MPEG-4 has its biggest advantage on video compression in general
and IP video transport in particular; … both developments require
significantly more calculations to be made in both the encoder and the decoder.
Together, these innovations have allowed a 50-percent reduction in bandwidth
for equivalent video quality as compared to MPEG-2 and have enabled new
applications such as HD video delivery over the Internet and by-way-of Blu-ray
and IPTV networks. MPEG-4 achieves many of its advances in compression
efficiency through the introduction of new video objects[1][1]
(Simpson); in MPEG-4 each element of a broadcast could be
generated separately and then transmitted as separate data units inside the
MPEG-4 stream, the decoder ... would process each of the different signals
elements and then combine them to form a video signal that is sent to the
viewer's display. In MPEG-2, all of the separate elements would be combined together
at the broadcaster's facility and then compressed and transmitted to the
viewer. Synthetic-image technology in MPEG-4 reduces bandwidth and gives
users control over items being displayed. MPEG-2 is an older
compression-version and do not have these innovations; it is less bandwidth
efficient when sending natural signals (brightness and color data) of thousand
of pixels.
[1][1]New video objects … created by the encoder from the natural
sources, such as video cameras and audio microphones, that capture input from
the natural world, or they can be created as completely new objects created
from synthetic sources that are generated through computer graphics or other
means; much less bandwidth is consumed when synthetic signal
are sent as compared to natural signals … due primarily to the innate
complexity of natural signals and the need to reproduce accurately the pixels
that make up a natural image(Simpson).
Simpson, Wes. Video Over IP. Burlington:
Elsevier, 2008. Print.
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