mpeg3dump: 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/mpeg3dump - from package: mpeg3-utils

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

Error in other languages:
mpeg3dump: bevel nie gevind nie
mpeg3dump: comandă negăsită
mpeg3dump: comando não encontrado
mpeg3dump: commande introuvable
mpeg3dump: command not found
mpeg3dump: käsku ei ole
mpeg3dump: không tìm thấy lệnh
mpeg3dump: komanda nerasta
mpeg3dump: Kommando nicht gefunden.
mpeg3dump: kommandot finns inte
mpeg3dump: komut yok
mpeg3dump: nie znaleziono polecenia
mpeg3dump: níor aimsíodh an t-ordú
mpeg3dump: no se encontró la orden
mpeg3dump: no s'ha trobat l'ordre
mpeg3dump: opdracht niet gevonden
mpeg3dump: parancs nem található
mpeg3dump: perintah tidak ditemukan
mpeg3dump: príkaz nenájdený
mpeg3dump: příkaz nenalezen
mpeg3dump: команда не найдена
mpeg3dump: командата не е открита
mpeg3dump: 命令找不到
mpeg3dump: コマンドが見つかりません