mpegtranscode: 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/mpegtranscode - from package: mjpegtools

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

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