I've searched a number of topics and tried a number of things now to try to get R5A12 work with my TV. The best I've managed is to get Myth playing in a small 4:3 rectangle within my larger 16:9 HDTV.

I am unable to install with the TV attached (even typing TV at the boot prompt - difficult as that is with no visible prompt). I am forced to install with a VGA display attached t the VGA-out of the nVidia 5200 card.

This is the first time I've tried to install Myth for HD. FWIW, I have generally had success with R5A12 with only a few exceptions - this being one of them of course.

After installation I pull the VGA display off, attach the TV via DVI and reboot. Sadly I see nothing during the wntire boot process - the MythTV UI comes up eventually however, but as I descibe: 4:3 and in a smaller area than the entire display.

Months back, from a Mac (Powerbook) I probed the EDID data from my TV and I believe it reported the usual suspects: suchnsuch x 480 (or was it 540?), suchnsuch x 720 and suchnsuch x 1080.

Perhaps the nVidia card has chosen a mode that is not the maximum? Still, I would expect the TV to scale then....

I edited /etc/X11/XF86Config-4 all night last night (I am new at this) to no visible effect. Specifically, although I added a parallel "Device", "Screen" and "Monitor" (one that I hope has characterisitics that reflect my TV) it is not obvious to me how you specify in the config file which of the many modes for which of the two "Screen"s etc. to use. The card has two "outs", so how is it to know which mode list is associated with which "out"?

Any experts on this?

I tried running mkxf86config (hoping it would return the EDID data from my TV in a XF86Config-4-friendly manner) but I appear not to know how to use this tool.

I wasn't aware that you could have two screen sections I believe you have just made a jumbled mess of the config file and it's just using the first thing it comes to.

You will need to find an appropriate modeline for your tv. Another problem is that many tv's use hdvi or dvih or something like that which is not particularly compatible with computer dvi.

important parts of my XF86Config-4 file (note do not use this directly on as a guide. I'm using vga->component converter, but concept should be similar)



note here only one of the lines is uncommented, but it has a few resolutions I can change to.

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Xsecrets

Someone had a sample config file that illustrated as much. I think it was for running "dual headed" though - who knows how MythTV would handle this scenario. I did not add the second screen to the "ServerLayout" section though (as I had seen done for dual-headed config).

So in your "Screen" section above, you list:



Fine. So which one does MythTV pick up? There are three listed there. Anyway to cycle through these in MythTV/Linux? (Sorry, I have a Mac background.)

And should I need to go back to using my VGA display for maintnence or whatever, I guess I have to restore my config file again? (Keep two copies?) This is why I was hoping to have parallel screen/monitor/card.

(John Calhoun == Astera, depends on whether I post from work or home.)

it always uses the first one if it is valid. to switch between them you use ctrl+alt+"+" however that leaves the virtual screen size the same the best way to change between them is to use xrandr.

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Thanks for pointing me to xrandr. When I ssh in and try xrandr it did nothing ("Can't open display (null)").

I went to my Myth box, exited MythTV, opened an XTerm and tried xrandr. Illuminating....

It says:



It seems to have pulled these modes from thin air. I was wondering why I could edit and edit and edit my XF86Config-4 and see no effect. There is nowhere in my config file these resolutions/timings ... it seems my box is in another reality.

Could my box be using one of the other config files? Like XF86Config?

Or could it relate to having no display attached to the VGA port of the nVidia 5200 (only a TV on the DVI port)?

You need to examine the log file produced by XFree86 when it starts up. It tells you in great detail which modelines it is using and which were discarded. It's in the directory /var/log and is called XFree86.0.log.

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I think the important thing here is to notice that both modes are 60hz refresh. I'll bet if you get some modelines at higher resolutions but keeping the same vertical refresh rate they will work. All of the modelines in my example have a 60hz (or close enough) vertical refresh rate. you could try them, but make sure that your set can accept those resolutions, and be ready to turn the tv off if you get wacked out stuff instead of a good picture.

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Thanks fopr pointing me to XFree86.0.log. THat log is amazing. I think I might see what is going on:



So since the HDTV returns EDID data, this is referecned and the modelines I've been entering have been rejected - why? Because they specify vertical resultions > 540. Likelt 640 x 480 is the only mode allowable.

I'm assuming now that the 540 limitation is a reference to 1080i. Since it is interlaced, I think TV's often threat the resolution as half of 1080. I just need to enter a modeline that represents something like 1920 x 540 with the proper interlaced flag set, etc.

I'll post if I get something to work.

The nvidia driver also allows you to configure X to tell it to ignore EDIDs:

Option "IgnoreEDID" "boolean"
Disable probing of EDID (Extended Display Identification
Data) from your monitor. Requested modes are compared
against values gotten from your monitor EDIDs (if any)
during mode validation. Some monitors are known to lie
about their own capabilities. Ignoring the values that
the monitor gives may help get a certain mode validated.
On the other hand, this may be dangerous if you do not
know what you are doing. Default: Use EDIDs.

(from the /usr/share/doc/NVIDIA_GLX-1.0/README file)

Depending on the device, this might allow you a stopgap solution for the time being until you put together the correct modelines. However, it may also be possible to overdrive your device if the original modelines weren't conservative. On CRTs, this was bad, not sure what it entails for flat panels.

-brendan

I would suggest you try one of the 1080i modelines that I have posted earlier, or find a 540p modeline.

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Xsecrets

Here is the setup I use for 540p using DVI on my sony grand wega. I can't guarantee it'll work for you but I've been using it for several months with no problems. I'm using 540 because I don't (yet) have an HD card so 540 is plenty.

I can't remember off hand what DisplaySize is there for. I think it may be to render fonts at a reasonable size. I'm sure a google search will show something.



Hope that helps. Good luck!

rich

yes the displaysize setting affects the font size. I didn't include it in my snippets, but I had to adjust mine too.

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As I mentioned, any modeline with a height >540 will prompt the EDID threat and will be rejected (I'm not going to override the EDID yet).

These sort of worked:



... but the image was unstable — would blank out from time to time (with the latter mode this happened every half second or so). Also, much too much overscan....

Otherwise, the image looked good (HD), the UI was centered and visible (though cropped due to overscan).... I'm going to keep plugging away.

Success! Here is the modeLine that worked:

Modeline for a Toshiba 30HF84 30" TheaterWide HD-Ready Flat-Screen TV (DVI in):



It was not arrived at by accident either. Specifically this is a modeline that is nearly dead-on spec.

For ATSC HD, 720p is defined to have a pixel frequency of 74.250 MHz (for 60Hz V frequency) — this one is within 0.1% of that frequency (74.160).

To compute the vertical refresh of theis modeLine:
74.160 / 1648 / 750 * 1000000 = 60.000 Hz
Dead on.

Since computer display cards like the number 8, those requirements are met as well (1648 - 1280 is a multiple of 8, etc.).

(I'm learning a lot about modeLines and display timing characteristics.)

This did require (thank you) setting the "IgnoreEDID" option since the TV was specifiying 540 as the maximum height.

BTW, this model TV is going for $700 at Amazon. I think I paid double that a year ago....