spumux: command not found

Have You tried accessing the binary with the full path?

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/spumux - from package: dvdauthor

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/spumux - from package: dvdauthor

You may install the required package with command apt-get install {package}
Error in other languages:
spumux: bevel nie gevind nie
spumux: comandă negăsită
spumux: comando não encontrado
spumux: commande introuvable
spumux: command not found
spumux: käsku ei ole
spumux: không tìm thấy lệnh
spumux: komanda nerasta
spumux: Kommando nicht gefunden.
spumux: kommandot finns inte
spumux: komut yok
spumux: nie znaleziono polecenia
spumux: níor aimsíodh an t-ordú
spumux: no se encontró la orden
spumux: no s'ha trobat l'ordre
spumux: opdracht niet gevonden
spumux: parancs nem található
spumux: perintah tidak ditemukan
spumux: príkaz nenájdený
spumux: příkaz nenalezen
spumux: команда не найдена
spumux: командата не е открита
spumux: 命令找不到
spumux: コマンドが見つかりません