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So
now we had both rival 50Hz and 60Hz HDTV production and transmission
systems. The Japanese had MUSE (multiple subnyquist sampling encoding)
and the Europeans had HD MAC (Multiplexed Analogue Components) for
Transmission.
The
European lobby made much of the fact that all the receivers would need
to be changed if the Japanese system won, they omitted to say that this
was also the case if the European system won.
For
production equipment the pinnacle of performance was achieved in the
late 80’s with large format CCD camera’s and uncompressed Digital
recorders.
The
early 90’s was a cooling off period though with some useful
standardization work including the much lauded common image format which
used the same 1920 x 1080 Image format for both 50 Hz and 60Hz.
The
end of the 90’s was dirty tricks time, influential senators remembered
that the Broadcasters had successfully quarantined spectrum for HDTV
Broadcasting and put pressure on them to make it so. The Broadcasters at
this time were preoccupied with the threat of mult-ichannel using
compression over cable and Sattelite. They then coined the phrase DTV
(Digital TV) and tried to deflect the politicians.
Enter
also at this time software vendors who could just about process Standard
definition in real time and didn’t understand the broadcast interlace
system. Using political influence and calling in High School Allegiances
they managed to initially dilute the DTV offering to NTSC Progressive
scan. The Broadcasters now seeing a threat from another direction then
switched back into an HDTV agenda.
The
outcome of all this was the infamous ATSC (Advanced Television System
Committee) table 3 with around 30 different broadcasting formats.
The
eventual result was a split between Broadcasters with some supporting
the normally interlace Common Image Format of 1920 x 1080 for both
Production and Transmission, and others supporting the 1280 x 720
progressive format much loved by the IT community. Progressive eats
double the bandwidth but was easier to process by the novice software
writers of the time.
With
luck in
Europe
the target for mainstream HDTV will be both the common image format
(1920 x 1080) and progressive scan.
Luckily
the NTSC Progressive Format also known as 480P has passed away.
Behind
this story the Professional Equipment vendors were trying hard to make
Equipment Better, Lighter, Cheaper. This resulted in a significant
degradation of picture quality over the costly but superior equipment of
the late 1980’s. In particular subsampling luminance and chrominance
then compressing it to death confused the format debate by seriously
degrading the capabilities of the 1080 I format. Another interesting
point was the realisation that Film images in 50 Hz systems were carried
as progressive images @ 25P. This concept went back to the 1960’s but
was invented as new and promoted heavily as the HD 24P system when the
term field dominance morphed into segment dominance. Woe betide anyone
who got the dominance the wrong way and tried to display motion on a
Digital Projector.
So
moving on to the middle of the first decade of the 20th Century, several
Broadcasters are on air, there is significant religion around the
various formats and finally the technology is approaching the
performance of the late 80’s but with a healthier price tag.
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