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TV clarity issue during fast motion scenes.
http://forums.linhes.org/viewtopic.php?f=6&t=1810		 Page 1 of 1
Author:  gr8nash [ Tue Jun 22, 2004 11:30 am ]
Post subject:  TV clarity issue during fast motion scenes.
I do know that this has been discussed before, with many people weighing in. However i was not sure after reading the various posts if there is a resolution. In my case i have an

AMD 2500+
512 ram
Via KT6 delta
haupauge 401 tuner
soundblaster 5.1

everything works great on the TV except during fast motion..(the example being used is Sports games) There is some weirs distortion. I do use the Deinterlace funtion as well as Jitter reduction. This isnt a bad problem..its just kind of annoying. I have heard that the Haupauge 250/350 has fast motion issues is that true?? Im looking for some kind of resolution.. even if its..just the way it is for now.. :)
Author:  Xsecrets [ Tue Jun 22, 2004 12:06 pm ]
Post subject: 
well there may be some very slight distortion even with the filters, but if it is highly noticeable you are probably using xvmc and the filters do not apply when using xvmc. Go to settings -> tv -> playback and on the page with pvr350 there is a checkbox down at the bottom of the page about enabling xvmc support make sure it is off.

edit :

Doh! I just looked at the next post and realized you were using a software card. Forget about the xvmc stuff as it won't be used for playback of your files no matter what.
Author:  ceenvee703 [ Tue Jun 22, 2004 12:12 pm ]
Post subject: 
Fast motion image problems boil down to two possibilities, both of which could be coming into play here:

1) not a high-enough bitrate. 4Mbps MPEG2 isn't high enough to hold it together during fast motion, or pans, or things like water or foliage or crowds. 6Mbps is better, 8 is better still. Note that capture resolution comes into play here too... 4Mbps looks better when compressing a 352x480 image than a 720x480 image. Since you're not using a 250 or 350, I forget what MythTV uses to capture.

2) deinterlacing. When you say it's not a bad problem, just annoying, and only during fast motion like sports, it could be that you're used to seeing sports on TV as interlaced, and now it's being deinterlaced by MythTV. Even if you don't turn on deinterlace, your TV out is probably deinterlacing it. I think the only way to preserve interlacing is to use a PVR-350's TV out... there may be other cards whose TV out preserves it (I heard Matrox once), but I'm not sure if their drivers also support interlaced output.
Author:  gazza [ Tue Jun 22, 2004 12:51 pm ]
Post subject: 
I was suffering this problem on motion scenes, and the most acceptable solution was to half the vertical resolution to 288 from 576 (i'm using PAL), and to crank up the bit rate to about 3500.

the quality is not quite as sharp, but the motion, and overall perceived quality is really good. It has the nice affect of reducing the load on the processor a bit too.

gary
Author:  gr8nash [ Tue Jun 22, 2004 2:17 pm ]
Post subject: 
i saw somewhere a chart that gave an equivivlent of capture resolutions..

ie.. 480 x 480 = ~TiVo


does anyone know where this chart is??
Author:  ceenvee703 [ Tue Jun 22, 2004 2:27 pm ]
Post subject: 
Quote:
does anyone know where this chart is??


I've seen others but there is one such chart in the MythTV documentation:

http://www.mythtv.org/docs/mythtv-HOWTO-21.html#ss21.3
Author:  gr8nash [ Tue Jun 22, 2004 2:32 pm ]
Post subject: 
Thats the ONE thanks!!!
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