recoder: 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/recoder - from package: emboss

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

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