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What's the deal? (August 2005)

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NG
noggin Founding member
harshy posted:
StuartPlymouth posted:
I can't see what all the fuss is with HD, I think my digital picture is quite good anyway - compared to what I used to get on terrestrial analogue.

Are the main electrical chains (such as Dixons, Comet etc) now showing demonstrations, because I wouldn't mind going to see one - then I might have a bit more enthusiasm for this "great TV revolution" Shocked


Well the current digital pictures are good, but compared to good quality analogue picture is poor, apparantly when you watch HD, the picture is very clear with no pixelation.


Well the compression artefacts in HD are smaller - because the samples/pixels are smaller. However you can reduce the picture quality of HD in just the same way as you can SD - by over-compressing and having too many compression stages in the distribution chain.

The Athens Olympics were covered partially in HD - and in the US there were complaints that the picture quality was less-than-idea because of over compression, tied in with a dodgy distribution chain. The source pictures were stunning - what got to people's screens wasn't ... It had excessive blocking on fast motion...
BO
boring_user_name
Quote:

Well the compression artefacts in HD are smaller - because the samples/pixels are smaller. However you can reduce the picture quality of HD in just the same way as you can SD - by over-compressing and having too many compression stages in the distribution chain.

The Athens Olympics were covered partially in HD - and in the US there were complaints that the picture quality was less-than-idea because of over compression, tied in with a dodgy distribution chain. The source pictures were stunning - what got to people's screens wasn't ... It had excessive blocking on fast motion...


Given the choice of heavily compressed HDTV and less compressed SDTV, I would always choose the latter. More pixels doesn't necessarily result in better quality. Hopefully though, as Sky will be using H.264, bandwidth shouldn't present too much of a problem, so we should be able to have both.

Also, I wonder if the SDTV channels will be broadcast in H.264. I doubt though that the current digiboxes have the necessary processing power to decode it. But if the sky digibox software would be rewritten in assembly, it might be possible!
NG
noggin Founding member
boring_user_name posted:
Quote:

Well the compression artefacts in HD are smaller - because the samples/pixels are smaller. However you can reduce the picture quality of HD in just the same way as you can SD - by over-compressing and having too many compression stages in the distribution chain.

The Athens Olympics were covered partially in HD - and in the US there were complaints that the picture quality was less-than-idea because of over compression, tied in with a dodgy distribution chain. The source pictures were stunning - what got to people's screens wasn't ... It had excessive blocking on fast motion...


Given the choice of heavily compressed HDTV and less compressed SDTV, I would always choose the latter. More pixels doesn't necessarily result in better quality. Hopefully though, as Sky will be using H.264, bandwidth shouldn't present too much of a problem, so we should be able to have both.

Also, I wonder if the SDTV channels will be broadcast in H.264. I doubt though that the current digiboxes have the necessary processing power to decode it. But if the sky digibox software would be rewritten in assembly, it might be possible!


Current SD Sky receivers decode the MPEG2 in hardware not software. To upgrade the SD channels to MPEG4 H264 you'd need to replace all of the current SD MPEG2 receivers.

For this reason it is unlikely Sky will move SD services to H264 for a while. There would be interesting discussions about Freesat etc. I guess...

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