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Discussion Starter #1
It seems I'm stuck with 60Hz on my Z2, which isn't the best for film sources. I'm a bit horrified that I didn't find this info while I was researching projectors -- I believed the multisync specs.


What is the best solution? I've been trying different Linux players, but the video is so jerky it's unwatchable. It sounds like Windows has some better solution. What is it? How do you get a HTPC to display a 24Hz NTSC DVD smoothly on a 60Hz projector?


I've been comparing the output to a cheap DVD player. I can't see any timing problems with the DVD player at all. I gather that there must be some judder. The Z2 does inverse telecine, reconstructing the 24 frames/sec, and must repeat a couple of them to get it to sync to 60Hz (unless its changing its internal refresh rate for svideo sources). How do I get the HTPC to be this smooth?


Is there any easy way to verify the refresh rates used by the Z2 when doing inverse telecine on a svideo input? I suppose I could try to master a NTSC disc with some sort of test pattern.
 

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I use a LT-150 running at 60Hz/1024x768 with my HTPC (also running at 60Hz and 1024x768).

(Ignore the following if you already know it...) It's important to match the native res and refresh of fixed panel pj's for good, clear playback. But it is technically multisync.. meaning It will accept a refresh from 60-100Hz and covert it to 60Hz. It just looks like crap when it has to scale/change refresh.


While 60Hz isn't the ideal exact multiple of NTSC/Film refresh (59.94/72 or something is best if you can do it from what I hear), I have no problems with it. Video is not jerky at all. If s-vid looks better to you than component/RGB from the HTPC in to the pj, I'd bet you're problems go far beyond a small error in refresh rate.


I'd wonder if jerkyness is a problem with the linux playback software. I tried going the linux route a year or so ago, but was never able to get smooth playback and solid a/v sync out of it. I moved to windows/theatertek, and not only is it easer to use (aspect ratio controls a must for me), it's never had a jitter or a/v sync problem.
 

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Discussion Starter #3
Quote:
Originally posted by etk29321
If s-vid looks better to you than component/RGB from the HTPC in to the pj, I'd bet you're problems go far beyond a small error in refresh rate.


I'd wonder if jerkyness is a problem with the linux playback software.
The image quality is, obviously, better from the HTPC. But the uneven playback rate makes it unwatchable. I'm sure it is a problem with the linux software, which is why I was asking: what do the Windows programs do to make 24Hz video playback smooth on a 60Hz display?


I never had uneven playback issues with a multisync crt, which I would set to 120Hz.
 

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Quote:
Originally posted by qbjkv
The image quality is, obviously, better from the HTPC. But the uneven playback rate makes it unwatchable. I'm sure it is a problem with the linux software, which is why I was asking: what do the Windows programs do to make 24Hz video playback smooth on a 60Hz display?


I never had uneven playback issues with a multisync crt, which I would set to 120Hz.
The player, or perhaps more correctly Directshow, do 3:2 pulldown to display 24fps material on 60Hz displays. This is the same thing that commercial DVD players do.


Because of the way clocks work in Directshow the 3:2 pulldown often is not as seamless as on STB players. Reclock is a very good solution to this problem since it provides a very stable reference clock.


I'm guessing that the linux players don't have very good 3:2 pulldown implementations.
 

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Discussion Starter #6
Quote:
Originally posted by jvincent
The player, or perhaps more correctly Directshow, do 3:2 pulldown to display 24fps material on 60Hz displays. This is the same thing that commercial DVD players do.
Doesn't 3:2 pulldown give you a 30Hz interlaced signal? Are you really using an interlaced video mode, which the pj would have to deinterlace?
 
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