subliminal: command not found

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 Debian possible default full paths are:

/usr/bin/subliminal - from package: subliminal

You may install the required package with command apt-get install {package}

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