So I am using SVP with RIFE 4.4 (so far only 4.4 can handle big 4k movies), I'm on an AMD card (7900XTX) with driver 25.5.1, trying to watch HUGE 4k movies.  It works fine most of the time, except recently I had some trouble and had to switch to Vaporsynth and MPC video renderer.  Anyway, now it has this weird behavior if Black Box detection is OFF.  The first screenshot is with BBD on, the second is with it off (having it off causes stuttering every 3 to 4 seconds with smooth periods between).  Only problem is, I don't want it on, because if a movie changes aspect ratios in one scene, it can cause glitchy behavior (a second of black screen, or causing the next scene to be in a wrong aspect ratio for a few seconds).  Any idea for a solution?

I switched to Avisynth just now and it said "GPU threads must be between 1 and 1."  on AMD drivers 25.3.2.  Vapoursynth working fine.

Ok, I reinstalled SVP and MPC, and used the SVP installer to reinstall everything, and it worked.  At first RIFE was really stuttery, but I disabled black bar detection and lighting effects and now I can watch 48fps videos using rife AI again smile

I guess I'll try a full reinstall of everything and see if that works.

Well with Avisynth I'm limited to 1 GPU thread, and it is very slow. 

>you don't need to download and install anything, SVP already has everything needed
- run Utilities - Set env. variables for Vapoursynth
- choose Vapoursynth Filter in MPC-HC

I tried that, and followed the instructions I saw on the FAQ.  After doing the utility -> setup environment for Vapoursynth I don't see any option for it in MPC-HC.  I even restarted my PC.

So it seems the only way to use RIFE with an AMD GPU now is to use vapoursynth.  Only problem is, I can't get it working.  Can anyone give me a simple step by step process?  I tried downloading Vapoursynth and installing it, and I even tried adding the .dll to MPC-HC but it doesn't do anything.  I don't see vapoursynth in the filter list.