Confirmed works on Mac, best method around afaik.
You'll need to install proper version of Python, I think its 2.7.16 but let me know if not.
Use avi codecs from ffmpeg, heres a lossless example with no b-frames and few i-frames:
ffmpeg -i input.avi -c:v h263p -q:v 0 -bf 0 -g 999999 -f avi output.avi
After that you need to "bake" it, MEncoder is the best bet right now. I think it's like this:
mencoder -ovc copy input.avi -o output.avi