xiph2vclt: 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 Debian possible default full paths are:

/usr/bin/xiph2vclt - from package: vclt-tools

You may install the required package with command apt-get install {package}
Error in other languages:
xiph2vclt: bevel nie gevind nie
xiph2vclt: comandă negăsită
xiph2vclt: comando não encontrado
xiph2vclt: commande introuvable
xiph2vclt: command not found
xiph2vclt: käsku ei ole
xiph2vclt: không tìm thấy lệnh
xiph2vclt: komanda nerasta
xiph2vclt: Kommando nicht gefunden.
xiph2vclt: kommandot finns inte
xiph2vclt: komut yok
xiph2vclt: nie znaleziono polecenia
xiph2vclt: níor aimsíodh an t-ordú
xiph2vclt: no se encontró la orden
xiph2vclt: no s'ha trobat l'ordre
xiph2vclt: opdracht niet gevonden
xiph2vclt: parancs nem található
xiph2vclt: perintah tidak ditemukan
xiph2vclt: príkaz nenájdený
xiph2vclt: příkaz nenalezen
xiph2vclt: команда не найдена
xiph2vclt: командата не е открита
xiph2vclt: 命令找不到
xiph2vclt: コマンドが見つかりません