enca: 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 CentOS possible default full paths are:

/usr/bin/enca - from package: enca

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

On Debian possible default full paths are:

/usr/bin/enca - from package: enca

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