dvd+rw-mediainfo: 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/dvd+rw-mediainfo - from package: dvd+rw-tools

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

On Debian possible default full paths are:

/usr/bin/dvd+rw-mediainfo - from package: dvd+rw-tools

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

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