Custom modelines are ignored for TV out

[MarkDoliner]

I'm trying to get 1080i TV out working but I can't seem to get it to use my custom mode line.

Lemme back up, 1920x1080i works great, except that the picture is too big for the actual display. So I want to tweak the mode line to make the picture a little bit smaller. But no matter what I do I can't seem to get X to even consider the mode line.

My display device is "TV-0." If I plug in a monitor instead of the TV then the log file shows that my 1920x1080 mode line is considered and promptly discarded (because the monitor doesn't support that resolution). But when using "TV-0" my custom mode line doesn't even show up in the log file.

I got the mode line by using the built-in 1920x1080i and then running `xvidtune -show`, so I know it's valid. Another interesting data point, when using xvidtune, no matter what I change I always get the message, "You have requested a mode line that is not possible, or not supported by your hardware configuration." Even if I change something then change it back to the initial value.

Are custom mode lines just not supported with TV out? Is this a bug? Is it hopeless? I could try buying a DVI to component converter... but I bought a video card with component out for a reason.

It looks like other people have had the same problem, with no real solution:
http://www.nvnews.net/vbulletin/show...ores+modelines
http://www.nvnews.net/vbulletin/show...ores+modelines

I'm using the 1.0.9631 driver on Ubuntu 7.04 (Feisty Fawn). x86-64.

[pe1chl]

This is a known problem, as you have found out yourself. I don't see why it is needed to answer that question again.

By how much is the picture too large? Some 16 pixels all around?
That is not a problem, it is the specification for a HD TV. It is not the NVIDIA card but your TV that is cutting off the extra, as directed in the SMPTE 274M specs for 1080i.
Of course this is inconvenient when you try to use your TV as a computer monitor displaying a GUI desktop, but that is not what TVs are made for.
When playing a movie, this should not be important.
When the amount cut off is more than that, there may be a different problem.

That said, it would be convenient when Linux window managers could be configured to use only a designated area out of the full desktop, i.e. place their taskbars and icons closer to the center than they normally do. It looks like Windows allows this, because users often report that "it is no problem with Windows" on the same hardware.

[MarkDoliner]

It looks like it's cutting off about 90 pixels on the left, 100 on the right, and maybe 15 on the top and 5 on the bottom.

[pe1chl]

That sounds like a problem in the TV. Not uncommon, unfortunately. My TV initially shows a nice picture, then after 2-3 seconds it does some "autodetection" and zooms the picture to a state similar to what you have. It is possible to shift it around using keys on the remote, but not to change the "zoom".

Again, TVs are not designed to be used as a pixel-perfect computer monitor. There will be uncontrollable scaling as well, meaning that small fonts are hard to read.
Even the presence of a DVI/VGA input does not guarantee much. Scaling and cropping is often done on VGA as well, and DVI opens up a whole new can of worms especially when using interlaced video (many threads on this forum about people fighting their HD TV with DVI input!)
When you want a 1920x1080 LCD monitor that can display HDTV as well, you need to get a computer display with TV functionality, not a TV with some support for computer input.

[rerushg]

Simply put: Custom modelines are not supported in TV-Out modes. That's in the NV documentation. That would be okay but NV overscan control option does not work (that's the "bug" part). So with an HD CRT you're out of luck with component out.

Only known fix (to my knowledge) is to go DVI/DVI with custom modelines, all pretty well documented in other threads.