Reinstalling AVISynth... What version do I need?

[Alwyn]

I've built a new machine and am going to try to re-install AVISynth, mainly for QTGMC. I am bamboozled by the various versions and they interact with Virtual Dub. For my last attempt, I installed everything, normal, plus, 32, 64 and it worked (how, I don't know!), but this time I want to use MT as well.

So, here is my aim:

System is Win 11 64bit (my previous install was on Win 10 64bit and it worked (great).

Use Virtual Dub 32bit for processing.

Use MT for AVISynth to speed up script processing.

From my reading, it appears that MT is simply a 6mb drop-in DLL to a normal AVISynth.

The question then:

Which version of AVISynth should I be installing, in terms of normal or plus and 32bit verse 64 bit and is there a different version for MT?

Thanks very much for any input.

[davexnet]

Why not just install the latest version of Avisynth Plus ?
It supports 32 and 64 bit environments depending on the bitness of the host program.

Do you have some other consideration?

[Alwyn]

Thanks Dave, can I add MT functionality to it?

[VoodooFX]

Thanks Dave, can I add MT functionality to it?

What do you mean add MT? Avisynth+ already supports MT.

You can use Universal Avisynth Installer to quickly switch between various versions.

[Alwyn]

What do you mean add MT? Avisynth+ already supports MT.

That's why I'm asking, Voodoo.

I have had a look at that Universal Installer; too hard; I'm not doing this because I enjoy it, so I'm looking for a simple solution. I simply want one version for QTGMC that has MT functionality that will install on my Win 64bit but will work with 32-bit VDub.

[jagabo]

If you work with high def video at all I highly suggest you use 64 bit AviSynth+ and 64 bit VirtualDub2.

[Alwyn]

I'm only working with SD video (tape captures). Any HD already looks fine to me!

[Alwyn]

I installed AVI Synth+ 3.7.2 from here:

https://github.com/AviSynth/AviSynthPlus/releases

As Voodoo says, it does support MT. I got multithreading to work with QTGMC using this as a sample script, running in Virtual Dub 2 32-bit:

SetFilterMTMode ("QTGMC", 2)
AviSource("H:\Video Tapes Albums\file.avi")
ConvertToYV12(interlaced=true, matrix="Rec601")
AssumeTFF
QTGMC(Preset="Fast", FPSDivisor=1, EdiThreads=8)
Prefetch(20)

MT gave a export rate around 300% of the non-MT export.

[jagabo]

Do you still have an i5 750? Peak throughput will usually be around 4 threads. 20 will usually give less throughput than 4. 20 threads would be more appropriate for a 20 core (or 10 core, 20 thread) CPU.

[Alwyn]

Jagabo, no, now an i7-13700K. 16 cores and 24 logical processes. It ran OK with a analogue capture, but with a DV AVI, VDub2 "ran out of memory" so I brought the Prefetch back to 16 and it ran without issue.

[Alwyn]

I have recently been getting memory error messages with VDub2 32bit (using it for Flaxen VHS filter, not available in 64bit) on my new computer. 64bit VDub is working well.

So I thought I'd uninstall AVISynth+ 3.7.2 and re-install AVISynth 2.6, which as resulted in my QTGMC throwing "no function named QTGMC". Crying!

I copied all my plugins from the 3.7.2 installation I had kept, and then tried all my plugins from my old machine (which used to run QTGMC OK), but to no avail.

From what I can gather, the FFTW library files aren't affected because I put them into System32 and Sywow64 myself.

I understand that the bitness of the VDub I open determines which AVISynth plugins are used, but I see that there are two folders for each bitness: plugins and plugins+

To help me try to understand how this whole thing works, here's my question.

What plugins folders are used when?

For example: I open an AVS in VDub 32bit. I assume it looks at the "plugins" folders (as opposed to the plugins 64 folders), but which one? The non-plus folder or the plus folder?

And a corollary question:

Why, if I install a non-plus version of AVIsynth, do "plus" folders get created in the AVISynth folder in Program Files (x86)?

[jagabo]

So I thought I'd uninstall AVISynth+ 3.7.2 and re-install AVISynth 2.6, which as resulted in my QTGMC throwing "no function named QTGMC". Crying!

I would avoid 64 bit Avisynth 2.6. It never worked very well. Use a recent build of 64 bit AviSynth+ instead.

From what I can gather, the FFTW library files aren't affected because I put them into System32 and Sywow64 myself.

Make sure you put the right one in the right folder. 64 bit fftw3.dll goes in the Sytem32 folder. The 32 bit version goes in the SysWOW64 folder.

What plugins folders are used when?

With AviSynth+ most 32 bit plugins and AVSI scripts work in the plugins+ folder. Most 64 bit plugins and AVSI scripts go in the plugins64+ folder. The only filter I had to add to the plugins or plugins64 folder are the MPPipeline files. You only need those if you plan to use MPPipeline (generally only to use a 32 bit plugin in a 64 bit AviSynth).

Why, if I install a non-plus version of AVIsynth, do "plus" folders get created in the AVISynth folder in Program Files (x86)?

Did you verify that your uninstall of AviSynth+ deleted those folders? Folders usually aren't deleted by uninstall if you manually placed anything in them.

[Alwyn]

Originally Posted by Alwyn View Post

Why, if I install a non-plus version of AVIsynth, do "plus" folders get created in the AVISynth folder in Program Files (x86)?

Did you verify that your uninstall of AviSynth+ deleted those folders? Folders usually aren't deleted by uninstall if you manually placed anything in them.

I wouldn't stake my life on it but I'm positive all 4 folders were created. That's what has confused me for a couple of years. On my old machine, I ended up pasting every plugin into every folder and it worked. I thought I had this new install worked out but apparently not. Anyway, I have reverted back to your suggested 64bit 3.7.2+, and with ChromashiftSP I'm reasonably happy (it's not as easy as Flaxen in VDub32 but I can't live with the memory errors and the lack of speed/MT).

I'm annoyed that I still am not really sure of how it all works, but at least it is working now (3.7.2+). I just want to get on and be productive, but also have an idea about how to reinstall when the time inevitably comes. Perhaps if I get bored I'll blow up the whole AVISynth install and start from a clean sheet to see what happens.

Thanks for your comments; they are really helpful.