4 x G450 PCI's zoomed from same desktop?

[Mr J]

Hi all, I'm working on a video installation project that requires the capability to set 4 separate areas within one 1024x768 desktop area (using zoom and pan) and then have each of the 4 set areas go out independently to 4 separate TV screens (i.e. 4 x composite PAL video-outs, each one zoomed from the 1024x768 desktop).

I'm thinking of using four G450 PCI cards but wondered whether they can be setup under 98Se so each card zooms on a different area of the primary display?

Any suggestions/experience/comments would me muchly appreciated. Thks - Mr J

[Ashley]

I probably misunderstood, but that doesn't sound posible to me. In principle, yes - but the resolution is too low. It would mean each screen was at 512x384 - and even if you set that up as a custom desktop resolution you'd never get the scan rate low enough for a PAL TV.

Wouldn't a resolution of, say, 1440x1152 spread across 4 screens make more sense, with each "head" set up to run 720x576x50Hz?

(Unless I'm mistaken, Matrox's zoom caps won't help you here.)

[Mr J]

Don't get too worried about the low resolution, for the use I have in mind each screen only needs to be half pal resolution (352x288).

I presently have a g400 and can zoom down to a minute window size (although I usually use 320x240), so I don't understand why you think I'd be unable to get the scan rate low enough for a PAL TV?

Basically I want to be able to open 4 movie windows on the primary display, then zoom onto each one and have each going to a different video-out. Forgetting the resolution for a minute, do you think this is possible to setup with 4xG450 PCI cards?

Rgds, Mr J

[Ashley]

I brought that up because a total desktop of 1024x768 divided among 4 monitors is 512x384 on each screen.

Well, 512x384 is normally double-scanned, and has the exact same timing as 1024x768x60Hz - and that's beyond the range of a PAL TV. Since you're already running at 320x240, you'll see what I mean: it's double-scanned to 43kHz. By comparison, 720x576x50Hz is only 32kHz. Now if you go into PowerDesk and try to reduce 320x240 down to a scan frequency acceptable for a PAL TV, you'll find the lowest PowerDesk allows is 39kHz/79Hz.

Anyway: on checking, I see that Matrox doesn't double-scan 512x384 after all (31kHz) - so you should be OK.

On that score anyway... I'm not sure what "4 movie windows" are, but unless I'm mistaken DeskNav only works on the primary monitor, and DualHead Zoom won't work with overlays...

[Tempest]

Since it appears that no one really has tried this setup here at MURC, you might consider heading over to the Matrox Support Forums and asking there.

[George YS]

Mr J, I think this is possible. But there is a better choice: if u don't work on 3D graphics, why don't u choose the G200 MMS card? It can support up to 4 monitors on a single card, and easier in installation than 2 cards.

[Mr J]

I think I need to re-explain the problem again, as I didn't do it very well the first time...

I run some video software that enables me to manipulate and display multiple avi movies in realtime. I can resize and position these movies anywhere on my desktop. I have a G400 dualhead card, with the primary display connected to a standard computer monitor displaying my desktop (presently set to 1024x768) and the secondary display connected to a TV screen.

Using the G400's zoom capability on the secondary display I am able to select an area of my desktop (i.e. one of the avi movies playing) and have just that appear fullscreen on the TV.

I'd like to be able to select four different areas of my desktop and have each going out to a seperate TV screen.

4 x G450 PCI's provide composite video out and zoom capabilities... BUT, what I'm trying to figure out is if I put four G450 PCI's into one PC can I set them up so the second, third and fourth cards show a clone desktop of the first card, and use the dualhead capabilities of each card to zoom into specific areas of the one desktop and display these out to TV?

The first port of the first card would display the 1024x768 desktop on a computer monitor, each of the four cards second ports would be hooked up to a TV screen, and the first port on the second, third and fourth card would not be used.

Have I managed to make this any clearer or are you now even more confused than me?

Rgds, Mr J

p.s. George YS suggested using the G200 MMS but as it doesn't support composite video out and I want to hookup TV's I don't think it's going to help. However I would be interested to know whether the G200 MMS can be used to zoom into four seperate areas within a 1024x768 desktop?

[Maggi]

Maybe too simple, but what if you'd take your G400, add three G450s PCI and set all to extend the desktop for VGA1 and into DVD Max mode for VGA2 ?

Your main purpose seems to be video playback and I think in this setup you could split your desktop into any desired resolutions (normal setup for your working monitor and three hosts for tool bars and video overlays) and could have four different fullscreen video playbacks on four TVs.

I have no clue if that actually works, but since Matrox is DualHead and if I remember right, PowerDesk supports up to 17 displays.

Must be a PIA though, trying to find out which monitor just got detected by Winblows, but it should be possible.

Cheers,
Maggi

[Mr J]

I did consider the option of extending the desktop over 4 cards and playing back the avi movie files fullscreen but this has a number of drawbacks. Playing back 4 seperate avi movies fullscreen at once on one PC is rather resource hungry, and bearing in mind PAL TV resolution is 704x576 (VHS is even less) I figured half pal resolution is more than adequate for my needs (plus it frees up PC resource to add realtime effects to the 4 seperate avi movies).

Any idea what you can set the minimum desktop resolution to in extended mode?

Rgds, Julian