Frame glitches (Prefetch?)

[radpopl]

I'm experiencing random errors in frames (frames 1st and 3rd are fine, 2nd has an an error in upper part) and I'm at a loss as to what might be causing it. The script is: LWLibavSource+Vinverse+QTGMC+lsfplus+Prefetch.
For now, I've changed the threads parameter in LWLibavSource to 1, but it didn't help.

The output file has a different length each time I encode it.
I plan to change LWLibavSource to BSSource/ffms2, but do you have any suggestions as to what might be causing this?
The source is an MP4 H265 file.

[radpopl]

Explanation: the top of the frame is shifted to the left by about 50px.

[pinterf]

Tough question, the script is a complex one. However there can be inconsistencies

• in the motion vector analysis if the internal multithreading is used. Which happens automatically when avstp.dll exists, due to the frame-slicing multithreading. I commented the source with three possible reasons, search "mt-inconsistency reason" in PlaneOfBlocks.cpp.
• a filter requires strict linear frame access, but it does not get fulfilled. Usually the special RequestLinear filter is used for helping that
• there is still a bug or bad assumption somewhere in the filter chain (not only mvtools)