Sometimes you'll need to move some files to custom repositories. Since sftp users can't access to moodledata dirs, this is best way to move video, pdf etc files incoming from users.
Basically, you give a directory to move from and change the target dir and all setup. Read the gist and setup cron accordingly.
Please check the url below to see:
https://gist.github.com/kunthar/9c7d2c9d8fc88ff39a0e0126b41674e3