Forum

VideoTexture across 2 outputs

vvvv beta general
#1

Hi All,

Im not sure why this is but if you are rendering a filestream>videotexture>quad and the actual area this renders to crosses over a monitor boundary (with extended desktop for eg in a windowed ex9 renderer) the playback stops or glitches. Other functions (3d etc) seem fine.

I thought this might be a limitation with directx but I dug ot an old dx app i compiled that renders video to texture and it works fine across monitor boundaries.

Is this issue likely to be fixed any time soon? It makes it kindof hard to do any multimonitor (multiprojector) work without span mode (which seems to fix it, but isnt always available)

thanks

#2

hehe,

this is something many of us have been wishing for ages already. bribe the devs, then we might get it :)

#3

hello, this is a classic DirectX limitation, video rendering works only on one device. but you can set you card to span mode (one vertical desktop) then it appears as one device to the software.

#4

to clarify this:

the _not rendering of videos on multiple devices is not genereally a direct3d limitation. as guest pointed out he has an application that does exactly that.

there are different ways videos can be rendered to textures:

  • vvvv uses the method “VMR9 in renderless mode” which we prefer as it can handle some of the operations directly on the GPU and therefore is typically faster. but the VMR9 can only render to one device.
  • the older, slower, more flexible method is to ommit the VMR9 and manually copy the video image to a texture on as many devices you like. this is totally CPU bound (and not _yet implemented in vvvv).

so i’d say there is still hope…
in the meanwhile…did windows7 get the spanmode back?

#5

Ah, shame.

Now i try some other stuff it seems to do the same freeze with other content (3d etc) that goes across a device gap.

Im not sure its a directx limitation?
Ive seen other apps use dx for rendering video that dont break over screens. CHeck the app at this url

http://cid-fbeb6373d9321a7f.skydrive.live.com/self.aspx/BlogYahoo/Viusal%20C++%20影像處理/20090614Ak%20-Texture3D9.rar

Its an oldish dx sdk demo app and seems to be fine when crossing devices…

Ofc opengl is fine with this issue too.

Woud there be a way to pass a ex9 render to a gdi render? I know its a stupid way to do it but would it make any difference?

#6

hmm enciding in link broke

just google for

texture3d9.rar skydrive

its the first link

#7

Ah joreg pre-empted me. ty for the clarification.

And no, unfortunately at the moment i hear windows 7 still hasnt got span back :(

Splitting the render with multimonitor fixes for 3d objects but not for video unless its wholly on one side of the device split.

Is vvvv in allegro? Im a c++ dude by trade, how hard would it be to write a node for this?

#8

allegro? no. vvvv is in pure delphi/directx. it shouldn’t be too hard to write this node, but it cannot be done as a plugin. so the problem is still the same…we need to find the time to do this.

#9

one solution for video, untested however but makes sense to me > play your video using flash inside of the renderer(flash), come out to a GDItexture and you’d be able to get this across 2+GPUs. CPU heavy i’d imagine.

#10

Lol sorry, don’t know why i said allegro, i was thinking delphi.
Ah well i will have to try and get span mode up or split synch the video (urg) or use something else for the time being.

Is it the same issue that freezes a 3d render window when its across a device gap? (or rather freezes one side)

#11
  • Is it the same issue that freezes a 3d render window when its across a device gap? (or rather freezes one side)
    exactly. but the that clipping for regular 3d stuff (except video) can be overcome. on a performance hit though: via inspektor on a renderer deactivate Clip Device. for what it’s worth…
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