[mythtv-users] FYI - vga, hdtv, and modelines

[Ian Forde]

Okay - here's the skinny.  I don't know much about HDTV and I got mine
working with myth (display out only - I'm not talking about receiving
HDTV broadcasts here.)  Here's what I did to make it work.

My HDTV (Toshiba 40h80) has a pair of component inputs.  One is being
used for the PS2, and the other (now) is used by Myth.  So I...

1. Went to Fry's and bought the RCA VHDC300 VGA->Component Video
(Y,Pr,Pb) adaptor.  I could have bought an Audio Authority for the same
$100, but then I'd have to buy it online.
2. Connected my mythtv box to a regular monitor.  No more TV-out
connector ever again.
3. Shut down my computer and disconnected both Linux/myth hard drives.
4. Connected a different hard drive (I had a 40GB lying around after
another home project) to the myth box, booted the box from a Win2k CD,
and installed... well... Windows 2000.

(I know that at this point people are wondering what the hell I'd want
to do a <insert deity here>-awful thing like that for, but trust me.  It
has a happy ending.)

5. Patched Windows box.  Patched, patched, and patched until it would
reboot no more.
6. Installed NVidia drivers and configured for "Single monitor".  Not
Twinview.  No "Clone mode".  Just "Single monitor".
7. Installed Powerstrip, available from http://www.entechtaiwan.net/
8. Grabbed the manual for my TV.  Found out what HDTV resolutions it
supports.  For my TV, I was limited to (according to the manual) 480p,
480i, and 1080i.  So now I'm using 540p. ;)  But I'm getting ahead of
myself here...
8. Followed (carefully) the instructions on
http://www.avsforum.com/avs-vb/showthread.php?s=&threadid=33207
After reading the first few sections I came to realize that if my TV can
do 1080i, it should be able to do 540p!

(A little note here - the directions on the aforementioned link are
about 3 years old.  The only real difference I had was that my computer
wanted to reboot after creating a custom resolution.  I let it reboot,
then I was able to select that resolution safely and keep working...
that's not mentioned in the guide...)

9. Once I had Windows displaying at the resolution I wanted, without too
much wasted space around the borders (horiz/vertical over/underscan
issues mostly dealt with) I clicked on the "Copy to clipboard" button on
one of the screens.

At this point, I celebrated.  I had just done a proof-of-concept that
the hardware works.  The rest is now just software configuration.

10. Start/Run/notepad
11. Edit/Paste

That last line was the modeline I needed.  I ended up doing 2 configs -
just in case.

12. Shut down the system, disconnected the Windows drive, reconnected
the Myth drives, and booted the computer.  Bear in mind that I'm *still*
connected to the monitor and *not* the TV at this point.
13. SSH-ed into the box from my laptop (where I'm writing this), brought
the box down to runlevel 3 (I just did an 'init 3')
14. Edited /etc/X11/XF86Config to put the modelines in.  Here are the
relevant sections:

Section "Monitor"
	Identifier   "Monitor0"
	VendorName   "Television Out"
	ModelName    "TV"
	DisplaySize  960	540
	HorizSync    31.5 - 37.9
	VertRefresh  60.0 - 60.0
	ModeLine	"almost540p" 41.062 960 992 1088 1216 540 541 548 563 +hsync
+vsync
	ModeLine	"My540p" 41.062 960 992 1088 1216 510 511 516 562 +hsync
+vsync
EndSection

Section "Device"
	Identifier  "Videocard0"
	Driver      "nvidia"
	VendorName  "Videocard vendor"
	BoardName   "NVIDIA GeForce 4 (generic)"
	VideoRam    65536
	Option      "RenderAccel" "1"
	Option      "NvAGP" "1"
	Option      "NoLogo"
	Option      "CursorShadow" "on"
	Option      "Connected Monitor" "VGA"
EndSection

Section "Screen"
	Identifier "Screen0"
	Device     "Videocard0"
	Monitor    "Monitor0"
	DefaultDepth     24
	SubSection "Display"
		Depth     24
		Modes    "My540p" "almost540p"
	EndSubSection
EndSection

The entire file is attached at the end, BTW... So then I...

15. Connected the VGA out to the converter box going to the TV.
16. Turned on the TV and switched to component input.
17. init 5
18. Configure Myth to adjust the GUI as necessary for me to see
everything I need onscreen.


How's that for 20 steps or less? ;)

	-I


-- 
                       __________________________________
                       Ian Forde, RHCE, CCSE, SCNA, SCDME
                       CYTBeN, Inc.
                       ian at duckland.org / ian at cytben.com