mpeg2enc: 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/mpeg2enc - from package: mjpegtools

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

Error in other languages:
mpeg2enc: bevel nie gevind nie
mpeg2enc: comandă negăsită
mpeg2enc: comando não encontrado
mpeg2enc: commande introuvable
mpeg2enc: command not found
mpeg2enc: käsku ei ole
mpeg2enc: không tìm thấy lệnh
mpeg2enc: komanda nerasta
mpeg2enc: Kommando nicht gefunden.
mpeg2enc: kommandot finns inte
mpeg2enc: komut yok
mpeg2enc: nie znaleziono polecenia
mpeg2enc: níor aimsíodh an t-ordú
mpeg2enc: no se encontró la orden
mpeg2enc: no s'ha trobat l'ordre
mpeg2enc: opdracht niet gevonden
mpeg2enc: parancs nem található
mpeg2enc: perintah tidak ditemukan
mpeg2enc: príkaz nenájdený
mpeg2enc: příkaz nenalezen
mpeg2enc: команда не найдена
mpeg2enc: командата не е открита
mpeg2enc: 命令找不到
mpeg2enc: コマンドが見つかりません