[mythtv-users] Phillips HDTV - xorg.conf - cannot see EDID

Brion Swanson brions at usalug.net
Mon Dec 17 11:37:42 UTC 2007


On Sun, 2007-12-16 at 23:20 -0500, David Fishburn wrote:
> On Dec 15, 2007 11:54 PM, Brion Swanson <brions at usalug.net> wrote:
> ...
> > Here's the relevant NVIDIA documentation for TV-Out Xorg settings:
> > http://http.download.nvidia.com/XFree86/Linux-x86/100.14.19/README/chapter-16.html
> >
> > And the section with all the options:
> > http://http.download.nvidia.com/XFree86/Linux-x86/100.14.19/README/appendix-b.html
> 
> Brion, thanks for the help and the links.
> 
> After much fiddling around I have come up with the following xorg.conf
> that gets me a hell of a lot closer:
> 
> Section "Monitor"
>     Identifier     "Monitor0"
>     VendorName     "Unknown"
>     ModelName      "Unknown"
>     HorizSync       30.0 - 110.0
>     VertRefresh     50.0 - 150.0
>     # Option         "TVStandard" "HD1080p"
>     Option         "TVStandard" "HD1080i"
>     # Option         "TVStandard" "HD720p"
>     # Option         "DPMS"
>     Option         "DPI" "100 x 100"
> EndSection
> 
> Section "Device"
>     Identifier     "Device0"
>     Driver         "nvidia"
>     VendorName     "NVIDIA Corporation"
> EndSection
> 
> Section "Screen"
>     Identifier     "Screen0"
>     Device         "Device0"
>     Monitor        "Monitor0"
>     DefaultDepth    24
>     Option         "metamodes" "1920x1080 +0+0; nvidia-auto-select
> +0+0; 720x480 +0+0; 800x600 +0+0; 640x480 +0+0"
>     SubSection     "Display"
>         Depth       24
>         Modes      "1600x1200" "1280x1024" "1024x768" "800x600"
> "640x480"
>     EndSubSection
> EndSection
> 
> 
> Couple of items to note (using ASUS M2NPV-VM Mobo nVidia GeForce 6150):
> 
> 1. Connecting via DVI - HDMI cable does not work.
> (WW) NVIDIA(GPU-0): Unable to read EDID for display device CRT-0
> 
> 2.  Using component cables does work (EDID).
> 
> 3.  My TV is capable of HD1080P, but adding:
>     Option         "TVStandard" "HD1080p"
> - Results in a fall back to 800x600 or such resolution and washed out colour.
> 
>     Option         "TVStandard" "HD1080i"
> - Provides me 1920x1080 resolution
> 
>     Option         "DPI" "100 x 100"
> - It wanted 75x75 DPI, but I was able to up it to 100x100.
> 
> 
> Running in "Unscaled" mode on the television results in a very
> annoying line of the far left of the screen about 1 cm wide that
> almost looks like the screen has wrapped around (though it has
> different text in it).  Not sure how to get rid of that.
> 
> 
> Some some final questions:
> 
> 1.  Is the GeForce 6150 capable of powering a HD1080P picture?
> 
> 2.  I thought DVI-HDMI (digital) was superior to Component (analogue).
>  Is this true and should I be able to see a difference (assuming I got
> it to work) between the two?
> 
> 3.  Should I take up these problems (EDID with DVI and so on) with
> nVidia on their forums (http://www.nvnews.net/vbulletin)?
> 
> 4.  If I am taking the plunge into HD content, was is a suitable
> amount of RAM?  I currently only have 1 Gig, which I was planning on
> increasing to 2 Gig.   I do a lot of transcoding (for the PSP and
> xvid).  Should I make it 4 Gig?
> 
> TIA,
> Dave

Hi Dave,

I'd suggest trying Mark's solution first to see if that works for you.
I can't really tell if the 6150 is capable of 1080p or not.  Searching
for it returns mixed results.

(seems to claim it can do it, but doesn't say how)
http://www.pcper.com/article.php?aid=167

(seems to suggest the max resolution is only 1920x1044 at 75hz)
http://www.nvidia.com/object/mobo_gpu_features_benefits.html#gf6nf4
("300 MHz RAMDAC
Blazing-fast RAMDAC supports display with high, ergonomic refresh rates
up to and including 1920x1440 at 75Hz.")

Another mixed forum (some say "probably" some suggest not)
http://avsforum.com/avs-vb/showthread.php?t=601451&page=39

As to your questions:

- For that line on the left, you might try playing with the TVOverscan
option.  I've not used it myself, but it might have some effect. "The
"TVOverScan" option can be used to enable Overscan, when the TV encoder
supports it. Valid values are decimal values in the range 1.0 (which
means overscan as much as possible: make the image as large as possible)
and 0.0 (which means disable overscanning: make the image as small as
possible). Overscanning is disabled (0.0) by default."

1. Can't really tell, but for the moment it looks like "yes, it's
capable but tricky to get working"

2. That's somewhat of a religious debate.  I personally see no benefit
to DVI/HDMI over component aside from fewer cables (1 vs. 3).  In my own
experience I got a richer picture out of component than DVI, but for
some devices that have both (I'm thinking high def DVD players) only
HDMI supports 1080p out, but that's usually an arbitrary limitation made
by the hardware, not the cable.  From what I've seen online, component
video cables are more than capable of supporting 1080p.  Over long runs
(> 30' on average) component video wins over DVI/HDMI because line
impedance causes too great of a signal loss on DVI/HDMI since the cables
were seemingly designed with little regard in this aspect.  Here's a
couple takes on HDMI vs. Component for your own edification:
http://www.engadgethd.com/2007/09/13/hdmi-vs-component/
http://www.bluejeanscable.com/articles/dvihdmicomponent.htm?hdmiinfo

3. Never hurts to check the forums and post your own questions.

4. The amount of RAM necessary depends greatly on what you plan on doing
with the machine.  My desktop has 4G of RAM because I do a lot of video
encoding and ripping.  My MythTV frontend connected to TV downstairs has
1.5 GB primarily for playback but I've gotten by with less - this
hardware just seems to complain (stutter) when I have less than 1.5, I
don't know why.  Another MythTV frontend upstairs has 1 GB and is
running just fine for all playback (up to 1080i for me).

Good luck and hope this helps at least a little.

Brion



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