I'm using an old ATI 3D Rage Pro PCI card.

I've got the composite output (tv out) working using the drivers from http://www.retinalburn.net/linux/dri_xv.html

Everything is working great for me except for one small problem - there are fairly noticable diagnal lines on my TV display. These lines don't appear when I use a VGA monitor on the card's DB15 connector, just on the TV. They seem to be most noticable along the edges of red areas, but they are actually present throughout the display, just more noticable on the edges of red areas.

I don't think this is an X config issue - the lines appear regardless of what resolutions I use, and they appear outside of X as well (for instance when the system is booting or shutting down.)

They almost look like RF interference, and at first I thought that's what they were, but a different video cable made no difference, and they seem too stable to be interference... if they were interference lines I would expect them to move about and such, and they don't.

My gut feeling is that these lines are artifacts from the card resizing the display for TV resolutions. From what I can tell through experimentation, the card's TV out functions more like an external scan converter - that is, X is configured for a normal 800 x 600 VGA monitor, not for TV. If I try to configure X to drive the display at native TV resolutions and refresh rates, tv out stops working. So, I think to X the card "looks like" a regular video card, and the scan converter on the card drives the TV transparently to X. If I'm right about that, then perhaps there's no way to fix this, as there might not be anything configurable, but rather a hardware limitation... but I hope not.

Any thoughts on how I might clear up these lines? They are kind of annoying.

Try a different resolution like 640x480...

No, as I mentioned in my original post, even outside of X (which would be a different resolution), the lines are still there.

I have also tried several different resolutions within X, to no avail. In fact, the diagnal lines I am refering to look exactly the same at 640x480 as they do at 800x600 or 1024x768.

Well that kind of puts a hole in the theory about resizing...

Have you made sure that the cable isn't picking up interference from somewhere? Interference can actually be quite stable especially if it's related to the base signal.

Otherwise it might just be a problem with the card or RF inside the case which is going to be fairly intractable. Sadly the TV out on most video cards is an afterthought to add a checkbox to the specs.

OBTW what kind of cable are you using? S-Video or composite video? It might be worth switching if you can to see if that changes the results.

Well... I think what the card is doing is resizing the image to a TV compatible resolution (I don't know what that would be... 576x420 or something like that?) So regardless of whether I use 640x480, 800x600, or whatever else, I think the card is still re-sizing it. In other words, obviously an NTSC TV can't display 1024x768, so the card must be doing something to what's in the framebuffer in order to display it on the TV, even though X isn't driving the card at a native TV resolution. Hopefully that makes sense. But you may be right, that may not have anything to do with it, it was really just a guess on my part, based on what the artifacts looked like to my eyes.


I've tried different cables, that's about it. I haven't gotten ambitious enough to try a whole nother computer, which is the only way I can really think of to eliminate any source of interference coming from inside the computer. I'll have to give that a shot I guess.


Both the TV and the video card only have composite connectors unfortunately, no s-video, or I'd be using that.

Here are a couple of photos of the screen that show what I'm talking about. Interestingly, in the photos the interference doesn't look like diagnal lines, more like a checkerboard pattern: one pixel on, one pixel off, one pixel on, one pixel off. I'm guessing that's because the camera is only capturing one field, and when the two fields are interlaced it produces the diagnal line effect that's visible to the eye. You can see the pattern along the left and right edges of Bob's blue robe in these photos, and esecially on the left and right edges of the red matt in the picture frame on the wall behind him:

so are you just talking about at the edges of stuff? if so it sounds like interlacing artifacts, and they can be minimized by turning on deinterlace. I would suggest bob.

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Xsecrets

Well, it's certainly more noticable on the edges of things, although it's not limited to that, just more noticable. It seems to be present throughout the picture.

Also, this isn't just when playing videos. As I've mentioned before, it isn't even limited to Myth, it's in *any* video coming out of the composite jack on this computer, even if XWindows isn't even running. It's noticable in the Myth menus, the KnoppMyth splash screen, etc.

I know it doesn't look that bad in the photos I posted above, but in person it's rather annoying.

Where exactly does one turn on deinterlace? I've been looking around the setup menus for about 10 minutes now but can't find it.

it's in the setup tv playback menu first screen I believe.

Also does this only happen on the mythtv box or anything plugged into that tv. I have a tv that has diagonal lines across the screen, but it has them for vcr's and game consoles also, so it's just a tv problem in my case.

_________________
Have a question search the forum and have a look at the KnoppMythWiki.

Xsecrets

Ah. I hadn't looked there, because this isn't something that happens just with TV playback, it's with ALL output from the MythTV box, as I mentioned above. In fact I actually don't even use this box for watching TV, just playing videos, DVDs, and VCDs. I just gave it a shot anyway though, and it didn't make any difference, regardless of what I set it to.


No, it's just with the Myth box. With input from a DVD player (on the same composite jack) it's fine.

Are you in a PAL or NTSC country. My TV is supposed to support NTSC, but I get the kind of funky thing you are seeing, possibly worse with the default TV out settings (NTSC). By adding

to the /etc/X11/XF86Config-4 file and restarting gdm using the follownig command from a console (ctrl-alt-f1) instead of an xterm my picture improved out of sight. I cant read the text in an xterm (even the large font xterm) until I do this.

I'm in the US, so NTSC, and that's what I have it set to in my XConfig. I still haven't had a chance to try the card in a different PC, and unfortunately I don't have another card with Composite out to try in this one.

I'm thinking more and more that it must just be the card though. Again it doesn't matter what resolution I'm running, whether I'm in or out of X, etc. Even on the BIOS boot screen the lines are there.

What would folks recommend for a CHEAP pci card with composite NTSC out? Cheap is the key word here, I really am on a budget. Soemthing in the range of about $10 (used) is what I'm looking for. I don't think that's unrealistic, as this card was only $5, and it works perfectly except for the lines.

I am having EXCACTLY the problem you describe. My Mythbox works perfectly otherwise.

The manual for my card, (ROSEWILL GFRCE RW5200-128D3 FX5200) says that there may be interference, and to try moving it away from the TV (I did, really far... to no effect) and to plug it into a different outlet than the TV (I did this too... no help).

Moreover, if I swith my TV set from monitoring the 'video in' to the "TV Tuner", the lines are still there, too. This is true as long as the cable is physically connected to my Myth box, even if the myth box is powered down. So there is definitely NOT going to be a software solution to this.

If anyone does find a good video card (I don't even care if it's NOT cheap), I'd love a recommendation!