pfsoutffmpeg: 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/pfsoutffmpeg - from package: pfstools

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

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