Advantages of Avisynth vs. Avisynth+ (plus)?
 

I've been trying to learn about using avisynth for restoring videos and I came across avisynth+ (plus). From most of what I've seen the documentation and scripts people have shared are for avisynth and there are some syntactical differences between the two. The documentation on avisynth+ is very lacking so I was wondering if the advantages of avisynth+ are worth the learning curve and lack of documentation?

To give background, I am converting VHS to DVD's in order to restore them, as well as attempting to restore VHS's that were already converted to DVD with a low grade recorder. The original tapes are destroyed so I know its going to be an uphill battle and I want to be best prepared as I can.

In my experience, the 32-bit Avisynth+ has issues.

I use the official 32-bit version, or the + x64 version.

And for 32-bit, I learned long ago to not use multi-threading, too many filters balk, and/or encode the video errors, giving random glitched frames.

64-bit uses 64-bit filters, while 32 uses 32.
Most filters are 32, not 64.
Some are just 64, not 32. KNLmeansCL is an extremely powerful quality filter.
Some are both. QTGMC is much faster in x64.

Depending on the filters needed, and desired output, I've become fond of selur's Hybrid in the past few months. The newer versions are finally working fairly flawlessly with both internal Avisynth and Vapoursynth filters.

Homefire,
If you are into restoring but haven't come across this yet....:

....Most were used/developed to restore from 8mm, but the scripts may be useful for VHS:

http://www.super-8.be/avisynth/Film_...vs_06_2012.zip (a collection of scripts/plugins/instructions)
http://www.youtube.com/watch?v=ihkD1tfmnhY (Apparently this guy developed his own tecnique. May have nothing to do with the contents of the zipped file above)

I've attached that file/

When it comes to film, and Avisynth, the online users "videofred" and "johnmeyer" have quite a bit of expertise and success. super-8.be is videofred's site. I've known and talked with John for probably 15 years now. He doesn't know much about VHS (my specialty), nor I film, so we've had some interesting conversations before about old 8mm/16mm film converted to VHS (as many people did in the 80s/90s).

There's an overview on the wiki of the differences. The big thing is support for higher bit depths (higher than the standard 8bits per channel/color), something that's not used a lot when it comes to captured analog video. I think it's the only version that's actively updated.

As person from a country that has some extra weird letters, one useful thing about it is that it seems to support unicode file names properly,. Older versions don't and have issues loading files with æøå and many other non 0-9 and A-Z characeters,.

One thing to note about avisynth+ (and 2.6) is that they support more planar color spaces (YV16, YV24 etc) than the older versions. This confuses some older filters that assume the input is YV12 when it's actually YV16, resulting in garbled output.