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uk.tech.digital-tv (Digital TV - General) (uk.tech.digital-tv) Discussion of all matters technical in origin related to the reception of digital television transmissions, be they via satellite, terrestrial or cable. Advertising is forbidden, with no exceptions.

Tennis on 1080i



 
 
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  #11  
Old July 15th 17, 03:10 PM posted to uk.tech.digital-tv
stephen
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Posts: 80
Default Tennis on 1080i

On Tue, 11 Jul 2017 10:12:23 +0100, "Brian Gaff"
wrote:

Its once again the old never mind the quality stuff. they mash up bandwidth
to the bare minimum to squeeze in as many junk channels as they can as
usual.


The EBU (who are sort of the technical club for European broadcasters)
did a load of comparison tests several years ago

The tests were done at lots of different compression ratios, mainly
with JPeg 2000 compression (as the broadcasters tend to push pictures
thru this over and over to get content around the system before
broadcasT)
- but the answers "should" give roughly the same types of answer no
matter what they do to the content just before it goes to consumers.

1080p = double the raw bandwidth of 1080i, so more compression needed
to get to a given transmission channel capacity.
- at any given quality level that seems to mean degradation from the
compression artefacts make the overall quality worse even though the
source material starts off better. JPEG 2000 is much more forgiving
here as it is designed to give lower compression but to degrade
gracefully - more aggressive codecs are needed for the higher
compression needed for broadcast.

1080i and 720p use the same bandwidth - starting with prgressive scan
and having double the number of full frames / sec in their tests
showed 720p was better for most content, esp those with more movement.

however in TV just like many other areas more screen lines is taken to
mean "better" - so TV has gone 1080i.......

The source material is always shot in a specific resolution and I
boubt broadcaster buy andything less than 1080p cameras these days -
but we still see pictures which look like the conversions made a mess
even before the compression was used.

Unless you are close to a big screen then your eye is actually the
most aggressive filter - as long as the compression system does a good
job and you dont lose important bits of the picture

And none of that matters much because someone at the broadcaster has
largely "baked in" the choices - it is going to be ainful and
expensive to change, so whenever that happens we will go to 1080p, or
possibly 4k....

The Freeview plattform is increasing being seen as the entertainment system
for the cheapskates and plebs.
Not that I care any more but when I think of whot could be possible, it
irks me just as the restriction on audio does on most platforms either by
using lossy codecs or just undersampling with that horrible gritty sound as
a result.

I was trying out ambient and sleep sounds on the echo yesterday, Evey one of
theem is irritating due to lossy compression. the phasing effects and
swizzling background in the stereo are just going to do the opposite of
relaxing you.
Sounds like a cheap tape player where the tapes have stretched and snake
over the head rather then going in a linear way.
Absolute crap.
Brian

Stephen Hope
Replace xyz with ntl to reply
  #12  
Old July 18th 17, 01:26 PM posted to uk.tech.digital-tv
klaus
external usenet poster
 
Posts: 11
Default Tennis on 1080i

Scott schrieb:

It should be noted in Germany 1080-50p DTT broadcasts are imminent (or
maybe already started ?)


Thanks :-)

Yes, it started already in mostly urban areas, but public service
stations are only up-scaling from 720p (Sat) to 1080p (DTT)...

 




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