[mythtv-users] Blending/spanning two crt projectors using myth and nvidia nview

[Steven Adeff]

On 2/21/06, Gene Stapp <genestapp at gmail.com> wrote:
> I checked the archives and couldn't find anything current on this
> subject so I'll go ahead and ask.
> I currently have two sony vph-1272q projectors. Their maximum resolving
> resolution is 660p but 720p looks good albiet a tad soft (I havn't felt
> like going through the 12 hour ordeal of totally converging everything
> yet since I moved) with a max resolution of 1600x1200... I'm looking at
> either horizontally spanning them, which would create a max displayable
> resolution of 1200p or rotating them 90 degrees so that my new max
> resolution when the two projectors pictures are combined would be
> 2400x1600 :)  . Both of these options would use a 16:9 display mode. I
> checked with the foremost authority with crt's on this and it is
> possible to span them so I am totally stoked...
>
> I'm going to try this setup with a overclocked 3200+ mobile (to 2.6ghz)
> and a 6800gt nvidia card. I looked through the search lists and it
> appears mythtv can output spanned content, but is there a performance
> hit and would I be better off using xinerama instead of nvidia nview for
> the spanning? Is there something I need to do with myth to enable
> spanning or does the video card drivers .conf file handle that without
> myth knowing. I found some previous threads from 2003 where spanning was
> turned off by default.
>
> Also what is the max resolution anyone has been able to run HD content
> in because the sky is the limit with this setup if it works correctly. I
> assume with XvMC support turned on the graphics card is the limiting
> factor? The HD content would be converted usually from 1080i but some
> 720p native movie content would also be used.

First, since these are front projectors theres no need to go above
1080p for HD content, so 1920x1080p would be the max your going to
want to drive with the two in parallel. Running a higher resolution
will not do you anything since it will require a processor to upsample
the content which is pointless for you.

Second, your best bet would be to get some dedicated hardware for
this. I know some high end projectors (Runco,etc) have devices for
doing this, you might be able to find something that will work with
your setup.

I've never seen anything for doing this driven from a PC. You'd want
to set up a Xinerama with two video cards (two PCI Express cards on
one of these new-fangled gaming motherboards), one above the other,
both set to 1920x540p and have the two projectors lined up so they
make for one fluid screen. Now, whether MythTV would be able to handle
using this setup I don't know, but thats the best way I can figure
getting it done.

I still think a dedicated peice of hardware for this would be the safe
way of going about it, if one can be found.

--
Steve