[mythtv-users] 350 Tv Out vs. Nvidia 5200

Jesse Guardiani jesse at wingnet.net
Mon Oct 24 10:35:49 EDT 2005

Jesse Guardiani wrote:
> Dave wrote:
>> On 8/23/05, Mark Gardner <markgard at gmail.com> wrote:
>>> Can anyone comment on the quality comparison between the two
>>> abovementioned chipsets?
>>> Advantages / Disadvantages, I have a 350 and have struggled on and off
>>> now for about 5 months to get it to work (Got it to work once but then
>>> the HD died).
>>> Mostly interested in quality of TV playback.
>> After using the PVR-350 for a year and a half, I've recently started
>> to transition to the NVidia 5200, solely b/c of HD compatibility.
> [...]
>> I'm pretty disappointed by the dramatic the difference between the
>> two, I expected the two outputs to "similar" like most people mention.
> My FX5200 is terrible compared to my PVR 350. No contest. Maybe these 
> people either:
> 1.) Have terrible TVs
> 2.) Use the DVI output on the FX5200?

I would like to officially flip-flop on this statement. I'm now using my 
Nvidia FX 5200
(128MB) AGP 8x **instead** of my PVR 350 for TV-OUT.

Advantages to the nvidia card over 350 for tv-out:
1.) BIOS POST, grub/lilo menus, kernel boot, text console, etc... ALL 
appear on the TV-OUT
     by default. This is great for debugging, dropping to the console to 
run some commands, etc...
2.) Hardware OpenGL support. Great for games, mythmusic visualizations, 
3.) AGP bus, so it saves a good bit of PCI bandwidth.

Advantages of PVR 350 card over nvidia for tv-out:
1.) *Slightly* superior TV-OUT quality (see NOTE below)
2.) Smoother playback sometimes, especially with ivtv-0.4.x
3.) Much simpler setup. The nvidia card takes a lot of tweaking before 
it reaches the same quality level.

NOTE: I said before that the nvidia FX 5200 had significantly worse 
TV-OUT quality, but
I no longer think it's quite so bad. After I turned on anti-aliasing via 
`nvidia-settings` the text
and (maybe video?) pixelation got a *lot* better. Also, using 640x480 
instead of 800x600
seemed to help a lot.

But here's the kicker: The last time I tried the nvidia card I had 
MASSIVE problems with
my video being "squished". (Incorrect aspect, basically) I thought this 
was a problem with
the nvidia card at first, but I've now learned that it was a SETTING in 
MythTV causing the
problem. You see, I had MythTV's Overscan feature turned on when I was 
using my PVR
350 for TV-OUT. This moved the OSD ('M' key during playback) to the 
right on the screen
and prevented it from getting chopped off. So I left that feature on 
when I switched to the
nvidia card (I guess I didn't understand it's real purpose yet). 
However, since the nvidia card
renders it's video more directly, I saw the true effect of the MythTV 
overscan feature: squished
video. I just didn't realize what it was because the 350's video isn't 
effected by this setting. So
basically, setting MythTV's overscan to '0' for width and height yields 
a really nice quality
TV-OUT with perfect aspect ratio on the nvidia FX 5200. If you need 
overscan on the 5200
(I did), then set it in your xorg.conf/XF86Config-4. The card does a 
much better job in hardware.

I think the 5200's TV-OUT is still slightly lower quality than the PVR 
350, even with everything
tweaked to perfection, but frankly it's still pretty darn good and the 
advantages far outweigh the
disadvantages for me. Anyone want to trade my PVR 350 for two PVR 150s?


Jesse Guardiani
Programmer/Sys Admin
jesse at wingnet.net

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