[mythtv-users] quality

match at ece.utah.edu match at ece.utah.edu
Tue Sep 12 14:29:54 EDT 2006

From:           	Sergei Gerasenko <gerases at publicschoolworks.com>
> I'm running MythTV 0.18 on a box with an nvidia card,

Which nVidia card?

> a 19" Dell 1950FP
> LCD and a PVR-150. When MythTV is running full screen (1280x1024), the
> quality is kinda bad.

How interesting. My experiences are very different. I run 3 MythTV 
boxen with CRT computer monitors. One is a 19" Dell, next is a 20" 
Viewsonic and lastly a Marquee 8500 CRT projector fed through its 
RGBHV interface. The picture is stellar on each one viewing SD 
content, running 1280 x 1024. In fact it's so good that you'd think 
the source was better than the 480 x 480 that we get from the card. 
(Even though the actual content from the antenna or cable company can 
only be resolved to 480 x 480, I have my capture set to 720 x 480. 
Can't really say with any authority that it makes a difference, I've 
never tried a lower setting.)

> From a distance, it looks pretty decent though. I
> understand that the "native" resolution of the PVR card is 480x480. If
> I'm planning to watch TV mostly on the LCD, what's the best way to
> increase the quality? Reduce the gui size? 

You haven't given enough information for me to help. It's doubtful 
that I could help anyway, because I've not had to chase a low quality 
picture issue. For that matter can you be more specific about what 
you're calling "kinda bad" quality? Is it pixelated? Snowy? Colors 
off? What?

I don't much like computer LCD screens, so I'd be tempted to blame it 
for the low quality, but that's just a knee-jerk reaction :-)

Bitrate too low maybe?
> If I decide to feed the signal to my TV, will it look much better? 

Not to me it wouldn't. I don't even own a TV anymore.
> BTW, I checked the deinterlace option. It didn't help too much, but
> improved a little bit.
> But even if I do 'mplayer /dev/video0' (and it's running in 480x480),
> the quality is not stellar. Is that all because of the fact that I'm
> using a computer screen?

Clearly my experiences indicate that the fact that it's a computer 
screen is not the issue, unless it's a particularly bad one. Did I 
mention that I don't like LCDs?
> The best quality I see is in those previews when I choose a recording to
> watch :)
> If this is a known "theoretical" problem, could you point me to a place
> where I could read up on it?
> Thanks for any suggestions!

All I could suggest would be to experiment with resolution and 
bitrate settings, or try another computer monitor for comparison. 


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