[mythtv-users] Asus M2NPV-VM - Component vs. DVI

Taco Mel taco_mel at yahoo.com
Thu Aug 23 18:05:51 UTC 2007

I've got everything working OK but I am trying to
fine-tune my settings for optimal display on my TV. 
The setup is:

* Asus M2NPV-VM (integrated GeForce 6150)
* Toshiba 65 inch rear projection HDTV (65HX83)
* Nvidia 9755 driver
* pcHDTV in separate backend
* Hauppauge in separate backend
* MythTV 0.21 (July 28 build from atrpms)
* No XvMC

The TV has both component and DVI inputs and I have
been able to get MythTV to "work" with both.  However
both have some caveats which I will note below.  I am
posting here in hopes of learning which caveats are
due to my configuration and can be fixed.

Component - running X with verbose logging indicates
that the TV out on the graphics card is capable of
only certain modes (one of which is 1920x1080).  There
is no 1776x1000 which I have read elsewhere is a good
match for my TV.  I can run it at 1920x1080 and then
run Myth with appropriate "geometry" options to
account for the overscan.  The picture is OK but Myth
information boxes -- e.g. the box at the upper right
that says "Paused" when it's paused -- can "flash" and
a test pattern with horizontal black lines flickers
badly and looks like a strobe.  Across the bottom
there is sometimes a line that starts at left as red
and transitions to blue at right.  Linux console is
overscanned but readable.

DVI - according to EDID the highest resolution the TV
can accept is 1280x720.  Overriding this and trying to
feed the TV 1920x1080, 1776x1000, etc., results in the
TV not displaying anything.  The menus look good (no
flash) and the picture is good.  I can run Myth with
appropriate "geometry" to account for the overscan. 
The disadvantage is that the fonts on the Linux
desktop are very fuzzy, almost unreadable.  Sometimes
there appears to be a reddish glow on the left side of
the screen.  There is nothing printed on screen during
boot (turn it on, wait for a minute, Nvidia screen
appears and everything starts up).  If you kill X the
console is unreadable, ranging from showing up 3 times
next to each other with purple lines dividing it, to
flashing, to nothing at all.

Here is where I need some advice:

1. Console needs to be visible/readable.  The overscan
does not matter, because I can SSH in for
administration.  But I need to be able to see what
it's doing (e.g. during boot) to troubleshoot any
issues.  Right now, component shows this
(overscanned), DVI shows nothing until the Nvidia
splash screen starting X.

2. Myth must fit on the screen correctly.  I have made
this work with both using the "geometry" argument.  Is
it better, for performance or picture, to scale it
with "geometry" or to try to use the setup menu or to
put in blank menu bars that correspond to the overscan
of the TV and then let Myth run "full screen"?

3. Myth's information boxes must look OK.  This is OK
with DVI and not OK with component due to some really
bad flicker on the component.

4. The Linux desktop to be usable (fonts readable). 
Right now they are fuzzy in both component and DVI. 
The larger Myth fonts are fine.

5. No artifacts.  Right now both the component and DVI
have artifacts (component, single colored line across
the bottom of the screen, very pronounced; DVI, subtle
reddish glow on left side of screen, sometimes visible
when watching a dark scene).

6. Hi-def picture.  Don't laugh at me for this, but I
don't know if I'm seeing HD.  Tpicture looks better
than with our (crappy and unreliable) cable box, which
couldn't reliably tune HD due to signal strength
issues.  Beyond that, signals from the Hauppauge and
pcHDTV look to me to be the same... with my poor
vision and wife saying "it looks fine" I don't know. 
If I am getting this through DVI then the set must be
converting the 1280x720 signal to 1080i... I am
feeding the 1280x720 signal with the BOB de-interlace
to make it look OK.

I would greatly appreciate any suggestions that would
improve any of the conditions I have noted here. 
Thank you!

Take the Internet to Go: Yahoo!Go puts the Internet in your pocket: mail, news, photos & more. 

More information about the mythtv-users mailing list