[mythtv-users] Nvidia 720x480 troubles

[Harley Peters]

Shawn Asmussen wrote:
> I upgraded to the new 6111 driver today, which went fairly smoothly. If I
> exit the X server, the text mode console looks garbled, but I don't really
> care about that, since obviously the box will be running in graphical mode
> pretty much all of the time.
> 
> I took the opportunity to try and get 720x480 resolution working. I hadn't
> been able to do it with the driver I was using before, and after fiddling
> around with it some more today, and trying a new modeline that I found, I
> got it to work. (The previous NTSC 720x480 modelines that I had found on
> the internet caused the X Server to complain that the hsync was out of
> range, when I tried them with the 6111 driver.)
> 
> Mythtv looked fine when it first came up under 720x480, although there is
> a little bit of unused screen at the top, which from what I understand I
> may be able to tweek using tools that come with the driver. I haven't
> tried that yet. Other than that little bit of space at the top, the mythtv
> menus fill the entire screen. When I watch a recording or live TV it's not
> so great. It works, but there is a significant amount of unused space at
> both the left and right sides of the screen, and the picture appears
> slightly squashed. This is not a case of the video card output failing to
> fit the screen. If I wiggle the mouse around, when it gets to the edge of
> the screen the mouse cursor becomes visible, and its location is at the
> edge of the TV screen, not where the playback picture stops. It seems that
> although the X server is displaying at 720x480, mythtv is only using the
> middle 640 columns for playback, although it uses the full available
> resolution for menus. When watching live TV, and I pull up the program
> guide, I also notice that the black empty space on either side of the
> picture shows up in the preview window also, although I'm not sure exactly
> why that is.
> 
> I'm using a PVR-350, and a PVR-250 in my box (Not using the TV-out on the
> 350 at this point obviously). I have the recording profiles setup to
> record at 720x480 on all of the profiles. My understanding was that by
> running the X server at 720x480, I would get the best results because then
> the video would not need to be scaled to the resolution of the X server.
> However, it seems to be getting scaled to 640x480 anyway. If it's
> relevent, 640x480 was the resolution I was using before I made the switch
> to 720x480. The only thing that even comes to mind is that mythtv is
> rescaling it because 720x480 isn't a 4:3 ratio. If that is the case then,
> I don't understand why 720x480 would be a desirable resolution to capture
> at, or to run on the X server. If mythtv will force the final output to be
> 4:3 scaled, then wouldn't it be better to just capture the video at
> 640x480, and run in 640x480 resolution?
> 
> I've tried looking through the archives to get a handle on this, but all
> I've learned for sure is that I don't really completely understand all of
> the issues involved with using different resolutions. If somebody can help
> clarify this for me, I'd really apprecitate it. My end goal is just to
> aximize the quality of my TV out. Most of what I have seen suggests to me
> that 720x480 is the best resolution to capture at with the Hauppauge card,
> and both common sense, and a few things I have read in posts to the list
> suggest that anything you can do to eliminate having to scale the image is
> good. Unfortunately for me, those two ideas don't seem to be meshing with
> each other very well on my system, and I'm not sure if it's just an issue
> of getting the settings right, or if some of my fundamental assumptions
> aren't sound. HELP!
> 
> 
> Shawn Asmussen
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You need to set your recording profiles to use an aspect ratio of square.
You will also need to set any other program you use (xine, mplayer ) to 
use square as well.
You really shouldn't need to do this but nvidia can't seem to ever get 
anything quite right.

Harley