Allow to use external compression software

[neimanpinchas]

Feature suggestion.

Hi

FreeFilesync is very good, what i think could be usefull for me is to have an option of specifying a own CLI program to process the files before and after send

Like lossless audio compression, etc.

Are there any related features?

[xCSxXenon]

FFS has a CLI which means you can write your own scripts and include FFS in them, meaning you can do just about whatever you want