usa anzi nice...

nice --help ritorna
codice:
root@v2410:/home/hfish# nice --help
Uso: nice [OPZIONE] [[COMANDO [ARG]...]
Run COMMAND with an adjusted niceness, which affects process scheduling.
With no COMMAND, print the current niceness.  Nicenesses range from
-20 (most favorable scheduling) to 19 (least favorable).

  -n, --adjustment=N   add integer N to the niceness (default 10)
      --help     display this help and exit
      --version  stampa le informazioni sulla versione ed esce

NOTE: your shell may have its own version of nice, which usually supersedes
the version described here.  Please refer to your shell's documentation
for details about the options it supports.

Report bugs to <bug-coreutils@gnu.org>.
root@v2410:/home/hfish#
quindi per lanciare con priorità bassa

nice -n 10 AVIDEMUX --OPZIONI