jori.hamalainen@teliasonera.com wrote:
I also agree, but I can be very ignorant on this. HDTV is a
'computer' display. And don't see any banding on my computer monitor which runs with 50Hz mains and 85Hz VGA. Or should I see, and what I should look for?
To the decision being based on history and politics, I would also add legacy. It will take some time before stations have enough HD native originated material to fill 100% of their schedules and what about re-runs of pre HD material? Keeping the frame rate the same means standard definition material just needs upscaling, rather than interpolating to a different frame rate as well. Look critically at material that has been NTSC->PAL standards converted to see the compromises the latter involves.
Is there need to up/downscale? See below..
But what happens after say 10 years, when hopefully all material is HD and we do not need to support legacy stuff. But still 50Hz HDTV system is used because of "legacy". I think that current 576i DVB is going to die within a few years. At least I hope there will be pressure from consumer side to move on from mid-60s TV-standard just with a digital transmission line. But I see a plot. First you sell all the people SD digital stuff, then sell them HD stuff. That keeps the commerce going.. :-)
I fear that 10 years is way too short time for anything to die on TV standars.
My current way of thinking is that if legacy formats are upsampled to HDTV resolution, HDTV channel still looks crappy on upsampled stuff, and probably won't do much more harm doing also the framerate conversion. And us Europeans are very used to this because of NTSC->PAL conversion. Also many broadcasters have SDTV co-channel for HDTV channel, so you can watch TV also via SDTV-side. This is the Australian model, have 2 streams per channel, one HDTV and one SDTV.
There should be no need for upsampling of legacy stuff nowadays - it's actually bad for transmission purposes (wastes bandwidth). HDTV receivers are required to handled rather great amounts of data so when receiving SDTV material all scalings, if needed, would be done at customer end.
About stations filling channel with HD-material. Every movie is HD. In 2005 every US serie is most likely filmed with HD. And if european broadcasting/production companies would purchase HD cameras/production stuff today, then all material would be HD (news, documentaries, homeland series, commercials etc). And who needs re-runs on HD channel. Keep the SD channel for those. HDTV tuners can also tune to SDTV.
Of course in my dreamworld HDTV channel should change framerate per show. Movies with 1080p/24fps, EU legacy series/stuff with 50fps and US series with 24/60fps. And that would also enable VDR to do 'easy' noad. If framefrate changes from 24fps to 50/60fps we have commercials.. :-)
Why this needs to be dreamworld? Upsampling/downsampling in realtime is not that big task for current CPUs so HDTV receiver could easily do this.
Better way is to let device produce correct picture for different standards. For old TVs this mean multi-norm TVs and most if not all LCDs and plasmas are capable of displaying requested framerates (configurable TDMS). Not sure about beamers/projectors but I assume they handle different frame rates as well.
This leaves us old TVs, which cannot show HDTV stuff anyhow so shouldn't be a problem.
For interlace to progressive conversion there are several algorithms already available for this work. Conversion can be easily done at realtime thus should not be a problem for any HDTV receiver.
I'd say that this is mostly matter of setting standards of the HDTV set top boxes to reasonably high level. For SDTV boxes it's too late to make changes to standards..
Removal of commercials.. that would be a blizz :) Luckily we have VDR that allows timeshifting. For me almost every serie starts 10min later nowadays :)
Or do you think that year 2020 DVB/576i is still alive? I hope that in Finland 2007 by dropping analogue TV-channels there will HD channels. Not 100 channels more of "reality-tv" with SDTV. VCR's are dying, most retail stores report that consumers don't purchase them anymore (at Finland at least). And has been VCR sold for about 25 years (1980-2004).
If you think about MTV3 or SubTV then I'll ask you that do you _really_ believe they will _not_ show old stuff ?-)
Channels that are funded with commercials are not keen "wasting" bandwidth to HDTV unless its competitors are doing so thus loosing viewers. Why? Simply because they earn more money by displaying more commercials in every 15-20min using multiple channels instead of couple of good quality HDTV channels. I believe, it'll be Canal+ etc. who will provide HDTV in Finland - at least in the beginning (after analogue channels have been shut down - hopefully by end of 2007 the latest).
Br, Pasi