mid3iconv: 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/mid3iconv - from package: python-mutagen

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

On Debian possible default full paths are:

/usr/bin/mid3iconv - from package: python-mutagen

You may install the required package with command apt-get install {package}
Error in other languages:
mid3iconv: bevel nie gevind nie
mid3iconv: comandă negăsită
mid3iconv: comando não encontrado
mid3iconv: commande introuvable
mid3iconv: command not found
mid3iconv: käsku ei ole
mid3iconv: không tìm thấy lệnh
mid3iconv: komanda nerasta
mid3iconv: Kommando nicht gefunden.
mid3iconv: kommandot finns inte
mid3iconv: komut yok
mid3iconv: nie znaleziono polecenia
mid3iconv: níor aimsíodh an t-ordú
mid3iconv: no se encontró la orden
mid3iconv: no s'ha trobat l'ordre
mid3iconv: opdracht niet gevonden
mid3iconv: parancs nem található
mid3iconv: perintah tidak ditemukan
mid3iconv: príkaz nenájdený
mid3iconv: příkaz nenalezen
mid3iconv: команда не найдена
mid3iconv: командата не е открита
mid3iconv: 命令找不到
mid3iconv: コマンドが見つかりません