Image Processing Reference
In-Depth Information
Maybe the Future Is H.264
Encoding with the H.264 standard is quite independent of the MPEG-4 frameworks. It
stands alone as a codec in its own right. MPEG-4 is only one of a variety of contexts in
which it can be applied. Depending on whether you are broadcasting a TV bit stream or
an IP-based broadband service, you may embed the encoded video in an MPEG-2 trans-
port mechanism or an RTSP stream of some kind.
Codec plug-ins for H.264 will almost certainly be available for all platforms and frame-
works in which video coding is currently used and some that we haven't yet thought about.
The European Broadcasting Union (EBU) is developing a strategy for high-definition
TV in Europe. Although the exact format and presentation are not 100% clear, it looks very
likely that the H.264 codec will be adopted for this. It remains yet to be clarified whether
the raster size will be set at 720 or 1080 lines but it will probably be progressively scanned
and run at a frame rate of 50 Hz. Bit rates of around 8 Mbps are being proposed, which
would allow 2 channels to be delivered within a single DTT multiplex. A DSat transpon-
der could carry 5 or 6 channels of high density at this bit rate depending on how the mul-
tiplexing is accomplished.
H.264 is certainly becoming very popular in the digital TV industry. Several satellite
TV operators have indicated that it is their codec of choice for next-generation TV services.
Or Perhaps the Future Is VC-1
Everything we might say about the potential of H.264 is also largely true of the SMPTE
VC-1 standard. Both are being proposed as possible coding schemes for HDTV broadcasts
and next-generation DVD players.
The VC-1 standard is independent of Microsoft because it is going to be licensed
through SMPTE or its agents. WM-9 will continue to be available as an alternative under
quite different licensing rules. VC-1 might be widely available and deployed on all oper-
ating systems. WM-9 will be available on Windows and whatever other platforms
Microsoft deems beneficial to its marketing.
Codec plug-ins for VC-1 will probably be available for most platforms and frame-
works in which video coding is used. At this stage it seems it will not be as dominant as
H.264 but it is very early in the life cycle for both codecs and hard to see beyond the short-
term future for both of them.
The biggest uncertainty about VC-1 is the current progress of the standardization
process. This appears to have become bogged down in a series of discussions and is not
moving forward as rapidly as was first anticipated. Originally, Microsoft promised a stan-
dard within 6 to 12 months of the commencement of the process. A year later, no clear date
has emerged for the release of the final document, probably because the amount of work
that was required was underestimated. It is likely that there will eventually be a VC-1
standards document but the question now is whether it will be in time to gain any market
share that has not already been won by H.264.
The chances of VC-1's achieving any kind of dominance seem to be receding as H.264
gains acceptance. There are predictions that any deployments of VC-1 will be short lived
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