TV deinterlacing

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rlevis

347 posts

Ultimate Geek

#72338 24-Nov-2010 15:39

Perhaps not quite on-topic, but close. Now that TV1 & 2 have moved to 1080i, all channels in NZ are now interlaced. It seems to me that modern TV's must have good deinterlacing to display Freeview from their built-in tuners at a good quality.

It makes sense to switch the HTPC to output 1080i and have the TV do the deinterlacing. It means getting away with a much less powerful gfx card.

But I was wondering, what type of deinterlacing do TV's do? Do they have a vector adapative delinterlacing chip these days?

nickrout

219 posts

Master Geek

#408969 24-Nov-2010 15:52

There are certainly mixed views on this topic. For example the more powerful nvidia cards using VDPAU do beautiful deinterlacing, so you'd probably be better getting the video card to do deinterlacing if you have a good card.

But it can often depend on the exact combination of card, TV and connection method.

richms

28168 posts

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#409111 24-Nov-2010 19:54

Outputting 1080i has never worked well for me, it seems the card deinterlaces and then reinterlaces it again after compositing the desktop image, and then the tv cant make its mind up between film or video mode on the PC output so it flips between them.

Most stuff worth watching is 24p sped up to 25p so will deinterlace fine. The only issues I see are where there is a video mode ticker on op of film mode content which you see on the bottom of C4 during select live.

Richard rich.ms

rlevis

347 posts

Ultimate Geek

#409155 24-Nov-2010 20:50

My TV (Sony Bravia 32") seems to deinterlace well and 1080i output looked pretty good. But this TV is only 1366 X 768 which is closer to 720p than 1080. It doesn't seem to resize down very well as I have found that the image at 1080p is not as clear as 720p, so in the meantime I'm sticking with 720p output. TV1 & 2 are not as good as they were before they changed resolution but it's not too bad.

I'm planning to upgrade to a proper 1080 TV next year.

richms

28168 posts

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#409183 24-Nov-2010 21:39

If its a PC, then outputting 1366x768 should give the best, but I was not able to get it to do that at 50Hz and accept it pixel native either on HDMI or VGA. I gave up and just ran it 60Hz, since most of what I watch is 24FPS as the nice people that cap it inverse telecine it when they encode it, and that works ok ;)

Richard rich.ms

rlevis

347 posts

Ultimate Geek

#409206 24-Nov-2010 22:12

My TV doesn't do 50hz either at native resolution, and TV at 50hz stutters every 1 or 2 seconds at 60hz because of the mismatch.