Posts
> Thanksgiving Day Channel 11 here in NY broadcast the NFL Network
production of the Giants/Broncos game had artifacts in what seemed to
be every transition. Maybe it was because of the rebroadcast
> Blu-ray looks spectacular, but sports can sometimes be dodgy, through
no fault of the set.
My dear Verne:
Broadcast TV has less data bandwidth than a Blu-ray disc. It is also
broadcast in the air, which adds lots of noise and possible
interference to the signal. Corrective data is provided in order to
mask some of these problems. If you are receiving a weak signal or
multipath, the TV must work harder to mask the additional errors. But
those errors may not be completely masked; there may be artifacts left.
Of course, additional data devoted to correcting errors also takes up
bandwidth that otherwise would be used to produce a better picture.
Another big difference is that the bandwidth that IS available for
broadcasting is shared with other additional services. WPIX Channel 11
for example is carrying a subchannel (11.2) called "LATV" which uses
about 1.5MHz of the available 19.3MHz bandwidth. OTOH, Blu-ray can
devote more of its available bandwidth to making high-quality pictures
and sound.
Finally, the type of compression used for each system may differ and
that can have a big effect on the quality of the picture. Blu-ray can
use either MPEG-2 or H.264. Broadcast TV (ATSC) can only use MPEG-2, a
less-efficient compression codec than H.264. If your Blu-ray disc uses
H.264 (which is most likely as it's the most common Blu-ray codec),
that fact alone can provide better results when compared to MPEG-2,
based on an equal data bandwidth available for video. This is because
H.264 is much more efficient at coding and decoding a high-quality
picture than MPEG-2 is. You really can't make a fair comparison
between broadcast DTV and any Blu-ray disc.
Dennis Degan, Video Editor-Consultant-Knowledge Bank
NBC Today Show, New York
------------------------------------
To learn more about the FinalCutPro-L group, please visit
http://groups.yahoo.com/group/FinalCutPro-LYahoo! Groups Links
<*> To visit your group on the web, go to:
http://groups.yahoo.com/group/FinalCutPro-L/
<*> Your email settings:
Individual Email | Traditional
<*> To change settings online go to:
http://groups.yahoo.com/group/FinalCutPro-L/join
(Yahoo! ID required)
<*> To change settings via email:
FinalCutPro-L-digest@yahoogroups.com
FinalCutPro-L-fullfeatured@yahoogroups.com
<*> To unsubscribe from this group, send an email to:
FinalCutPro-L-unsubscribe@yahoogroups.com
<*> Your use of Yahoo! Groups is subject to:
http://docs.yahoo.com/info/terms/
No comments:
Post a Comment