[HELP] Any ideas on how to handle a variable FPS source?

[Selur]

Why is it a bad idea to use Scale with bob? Why does Scale increase the length of the video in this case to 4:00:00 if according to the description it clearly shouldn't?

My guess the problem is that you mix Avisynth/Vapoursynth and FFmpeg parameters,...
Would need a debug output level 9 of the job creation to know what exactly happens (Hybrid thinks you want).

Why is it a bad idea to use Scale with bob?

Because, scaling is a stupid option, it simply drops frames without any intelligence. So it should only be used in some rare cases.

I'm aiming for turning the 720x480 interlaced source into 1440x1080 progressive 60fps.

Assuming your frame rate is 29.97 bobbing on it's own should already to the frame rate adjustment.

but I am currently struggling with the variable fps.

no clue where that comes from,... but you can tell Hybrid to decode to cfr,...

For example so far QTGMC doesn't even apper for me under (De-)Interlace/Telecine tab and I can't find anything resembling it under the Avisynth tab. The only mention of it is in the deinterlacer help window.

Are you perhaps using NVEnc and enabled 'Only use encoder'

Only use encoder:
When only NVEncC will be used, so no Avisynth, Vapoursynth or filtering through FFmpeg or Mencoder.

Cu Selur