[HELP] "Real" PAL<>NTSC framerate conversion with speed changing?

[shijan]

I can reproduce same problem on macOS if use like this:

Video to passthrough
Muxing->Overwrite->Frame rate set to '50'
Audio' to 'custom'
Audio->Base->Audio Encoding Options->Filtering->Speed change  set to '50'

Same pop-up message:
"Can't use FFmpeg for muxing with video passthrough since output(50) and input(25) frame rate differ!"