oggenc: 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 CentOS possible default full paths are:

/usr/bin/oggenc - from package: vorbis-tools

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/oggenc - from package: vorbis-tools

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

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