MPEG and sports image enhancement

[John Mason]

I babbled on at length starting last Saturday about the poor quality of
ESPN/ABC golf shows I'd viewed for two weeks. Noticed the problems on a
new HDTV/NTSC Philips 64-in. RPTV that uses 9-in tubes.

Caught the Seniors Open on ESPN from the Detroit area Thursday afternoon
(7/13) and immediately saw a vast improvement. Long shots of the
fairways contained considerably more detail, giving more of a
you-are-there feel to the images. I'm still detecting, on medium-close
shots, the bizarre appearance of what looks like dandelion stems where
there are none on the fairways and greens. As the focus shifts slightly,
these stems 'squirm'. I'm used to observing fairly subtle changes in
signal quality between programs, ads, etc. on a 29-year-old video-only
7-ft. projection TV. But the new Philips set makes it easy to detect
even slight shifts in quality from one field camera to another.

Also today, watched some really bad signals from a Golf Channel
broadcast of a game from Scotland, converted from a British (BBC?)
signal. Most of the time the fairways and greens looked like pale green
felt, devoid of any detail and realism. Wonder if MPEG encoding causes
this because the grass is stationary and to save bandwidth it's over
compressed? A few shots showed this fuzzy fake-looking 'grass' in the
foreground with water in background with moving ripples. Thus the
distant water and receding ripples seemed very sharp compared to the
featureless grass.

New set problems or misadjustments? At any time, when I switch to a
premium channel, piped to the Philips via a digital-cable, SA-2000
Explorer converter, and an S-video cable, the movies seem nearly perfect
in quality. Two HDTV channels via the cable provide still another huge
jump in picture quality; from 8-ft away, it's superior in many respects
to typical theater viewing of films.

Thanks to all who earlier provided some 'insider' comments re golf balls
with ears and squiggly grass. --John

[Jay B]

John Mason <jma...@banspam.com> wrote in message
news:396E6FA0...@banspam.com...

<Snip Comments on Ford Senior Players Championship Quality>

> Also today, watched some really bad signals from a Golf Channel
> broadcast of a game from Scotland, converted from a British (BBC?)
> signal. Most of the time the fairways and greens looked like pale green
> felt, devoid of any detail and realism. Wonder if MPEG encoding causes
> this because the grass is stationary and to save bandwidth it's over
> compressed? A few shots showed this fuzzy fake-looking 'grass' in the
> foreground with water in background with moving ripples. Thus the
> distant water and receding ripples seemed very sharp compared to the
> featureless grass.
>

Different video standards. 625 lines down to 525 lines means 100 lines of
information are missing. Add in compression, transmission, re-transmission,
and distribution from the head end...you get pictures exactly the way you
describe them.

Regards
Jay B
Freelance VTR/Profile/EVS Op

[Stephen Neal]

Jay B wrote in message ...

The Golf that I have been watching on the BBC in the UK has also been 16:9
(i.e. Widescreen) on the digital BBC channels, with the central 4:3 portion
being broadcast on the BBC analogue channels (and I guess this 4:3 feed is
the distributed internationally). The 16:9 stuff still looks like it has
been produced with PAL in there somewhere (rather than remaining digital
component) - probably still analogue PAL radio camera links still in use.
The pictures are not terrible - but they are not amazing either... 16:9 PAL
does look pretty horrid.

The colour bandwith reduction and concatenation of compression artefacts
caused by using 16:9 PAL, decoding to component (possibly) in the OB truck
(many - but not all - BBC OB trucks are digital component), distributing to
London via a compressed digital link (possibly with a recode to PAL for use
on an analogue PAL link between the OB and receive site), taking a 4:3
central cut out at TV Centre in London, recoding this to PAL, then sending
to the US over a (no doubt compressed) digital link, then converting to NTSC
before distributing the final signal to US households (again with digital
compression) cannot be pretty... (It may be that the PAL is converted to
NTSC in Britain - but the chain is still horrible...)

Interestingly Wimbledon this year was 4:3 throughout - but the production
process was almost entirely digital component - and the pictures did look
very nice. I think it remained 4:3 (this weeks Davis Cup coverage from
Wimbledon is 16:9) because the sheer complexity of converting all the
individual camera and court feeds to 4:3 would be difficult - but you never
know - it may happen next year...

Steve

[John Mason]

Wow. Appreciate the insider details. I suspected what was going was
complex, but that's horrific...no wonder this Golf Channel setup looks
like it does. I watched the seniors ESPN game broadcast from near
Detroit, Mich., described above, in 16:9 mode, too. But of course that
was stretched 16:9, with most electronic stretching occurring near the
picture edges. In this broadcast the result was gorgeous because it
provided, from only 8 ft. away, a full field-of-view image of intense
deep-green fairways, with adequate details such as fairway criss-cross
mowing receding into the distance. Stretching Mother Nature like this
makes it easy to ignore the distortion--although I hate it--but of
course on closeups of players you often see grossly exaggerated widening
of shoulders, hips, etc. Missed the CBS HDTV broadcast of the Masters
game in the U.S.(no receiver), but those who saw it are still talking
about the extraordinary fidelity. -- John