F-String errors and FFMPEG aspect ratio if width is not divisible by 2

[viper86it]

Hi,
thank you for your work! It's exactly what I'm looking for.
Anyway I spent a bit of time to get it working, your code has a lot of errors with f-string syntax.

I've corrected all strings is commander.py, preview.py and ffmpeg.py. Please check attached files. Now works well with python 3.10.12

In ffmpeg.py, in function generate_preview_chunck(), it was an error related to file width calculation. Using "-1" is calculated keeping aspect ratio, but if width is not divisible by 2 ffmpeg returns an error.

To solve it I changed:
-vf {scale}=-1:{args.resolution}{video}
to
-vf "{scale}=-2:{args.resolution}{video}"

as explained here:
https://trac.ffmpeg.org/wiki/Scaling

I hope this will help you:
Fix.zip

[Tetrax-10]

Thanks for reporting the bugs and suggesting fixes, really appreciate your effort 👍.

Done! 5046551

Check out v1.3