SpanMode vs. DualView

On Windows XP graphic card drivers offer two different modes to use multiple monitors on 1 card:

• SpanMode treats multiple monitors together as one DirectX device.
• DualView treats each monitor as a single DirectX device.

A current limitation of Videotexture (EX9.Texture) and VideoTexture (EX9.Texture YUVMixing) is that they can only playback on one DirectX device at a time. Meaning that in DualView you can see them only on one monitor.

SpanMode (only available on Windows XP)

• Multiple monitors together form one DirectX device
• Renderers always go fullscreen spanning over all the outputs of the graphic card

In this mode you can play videotextures on multiple monitors, but you can't go fullscreen on only one of the monitors and have the patches on the other. SpanMode always only works on one graphiccard, the desktop cannot be spanned via several graphiccards.

DualView

• A DirectX device is created for each ouptut on the graphic card
• Renderers go fullscreen on individual outputs independently

In this mode a videotexture plays only on one of the outputs at a time and you can go fullscreen with a renderer on one monitor while still patching on the other.

Overcomming the VideoTexture limitations

Option 1

Use two filestreams and two videotextures where each is connected to one of the renderers to see video on both renderers/devices but they'll probably not be in sync and you risk bad performance.

Option 2

Use VideoIn/FileStream->sharedmem->videotexture->quad
for one device. and then use sharedmemtexture->quad for the other devices.

Graphics expansion Modules

Graphics expansion modules are small black boxes that let you connect two or three monitors to a single VGA, DVI or DisplayPort output and use your system's GPU across all monitors. Via a custom EDID they make your PC believe that only one monitor with a resolution of e.g. 3072*768 Pixel is connected.
Well known products are Matrox DualHead2Go and Matrox TripleHead2Go

Links

related vvvviki-pages

• Device (EX9 Auto)
• Device (EX9 Manual)

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