Green screen frameserving from VirtualDub to Mainconcept

[tokumaru]

Hi guys,
I'm starting to use the Mainconcept MPEG Encoder, wich seems really nice and works very well when I load the videos directly from files. However, when I try to frameserve from VirtualDub, all I get is a glitchy green screen, wich can be encoded, resulting in a mpeg containing only the same green screen. Has anyone ever faced the same problem that could by any chance tell me how to fix it?

When I look at the frameserver window, the count of "non A/V requests" rises a lot when I open the file in the encoder. Do you think it has anything to do with the problem?

Thanks for the help!

[celtic_druid]

As I recall uninstalling XviD solves the problem. No reason why MainConcept should be loading or using XviD though, so I would say the bug is with it and nto XviD. Could also frameserve with AVISynth instead. Not sure if MainConcept can handle YV12 input or not.

[redwudz]

What type of file are you frameserving from? That sounds like a problem with a Divx or Xvid codec.

Take a look at this thread, it sounds like a similar problem.

https://www.videohelp.com/forum/viewtopic.php?t=239666&highlight=green+screen+frameserving

For some more, try a forum search for 'frameserving, green screen'

Ahh, It looks like celtic _druid may have beat me to it.

But try the search if you don't get anywhere.

[SatStorm]

XviD decoding had (or still has??) a "bug" when you set it up to be used for decoding some other mpeg 4 files.
Unistalling XviD solves this issue. A strange bug indeed

[celtic_druid]

No, I'm not talking about XviD decoding or MPEG4. I am talking about how if you frameserve from VDub to MainConcept that you get a green screen whether the file is MPEG-4, XviD is used to decode or not. You could open a VP7 encoded avi in VDub and you still get the green screen.

Like I said there is absolutly no reason why MainConcept should be using XviD in such a case, so I don't think it is an XviD bug. Something to do with colourspaces I guess. But then it only effects VDub framserver input. Still the fact is that I disabled some of XviD's colourspace routines and the problem no longer occured even with XviD installed.

So to sum up, if you really want to frameserve from Vdub to MainConcept, then as far as I know the only solution is to uninstall XviD.

[mats.hogberg]

Sounds likely - about the only thing I haven't tried to sort this out. (I too get green screen when frameserving VDub -> Mainconcept). Avisynth -> Mainconcept works fine, tho!

/Mats

[SatStorm]

@celtic_druid: All I say is that xvid has that bug and for a strange reason affects the frameserving from Vdub to Mainconcet (but not TMPGenc or CCE for exampe...)

I don't know why that strange thing happens. All I know is that it has something to do with that bug I said. And in the matter of fact, it has to do with how xvid handles / conflicts with 3vix or something (I read something like that years ago, I don't remember exactly what happens).
As you pointed, when you unistall XviD you can frameserve with vitrualdub again to mainconcept.

[tokumaru]

Wow, celtic_druid was absolutely right... uninstalling XviD solves the problem! I'd just never think of that, as I was working with a DV file. I tried to disable the decoding of other support mpg4 formats first, but that didn't help.

It will be a pain if I have to uninstal/install XviD whenever I want to encode an edited video... maybe I should just try Avisynth.

Thank you *VERY* much for the help, guys! I could never have guessed what the problem was! You are all just great! =)

[celtic_druid]

Got nothing to do with 3ivX.

I still say that the bug is with MainConcept, not XviD. Like I said there is really no reason why MainConcept should need to load XviD in such a case.

As I said it has something to do with colourspaces. For some reason MainConcept uses XviD to convert or something, since when I disabled all those routines in XviD VfW, the problem was gone. That means that you couldn't feed XviD various colourspaces as input anymore though.

My advice is just not to use VDub for frameserving. If you load another RGB24 source then it doesn't happen. Only with VDub.

Ok, so MainConcept uses XviD to convert the RGB24 VDub source. XviD converts it to YV12 since that is what XviD uses for encoding. MainConcept doesn't like YV12 so you get a green screen. That is what I think is happening anyway. Doesn't explain why if you load a different RGB24 source it doesn't do the same thing though.

Either way, if you disable XviD VfW's RGB24 conversion routine, no more green screen. Also no more encoding with XviD from a RGB24 source. Not that anyone should be doing that anyway really.