ffmpeg2theora: 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/ffmpeg2theora - from package: ffmpeg2theora

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

Error in other languages:
ffmpeg2theora: bevel nie gevind nie
ffmpeg2theora: comandă negăsită
ffmpeg2theora: comando não encontrado
ffmpeg2theora: commande introuvable
ffmpeg2theora: command not found
ffmpeg2theora: käsku ei ole
ffmpeg2theora: không tìm thấy lệnh
ffmpeg2theora: komanda nerasta
ffmpeg2theora: Kommando nicht gefunden.
ffmpeg2theora: kommandot finns inte
ffmpeg2theora: komut yok
ffmpeg2theora: nie znaleziono polecenia
ffmpeg2theora: níor aimsíodh an t-ordú
ffmpeg2theora: no se encontró la orden
ffmpeg2theora: no s'ha trobat l'ordre
ffmpeg2theora: opdracht niet gevonden
ffmpeg2theora: parancs nem található
ffmpeg2theora: perintah tidak ditemukan
ffmpeg2theora: príkaz nenájdený
ffmpeg2theora: příkaz nenalezen
ffmpeg2theora: команда не найдена
ffmpeg2theora: командата не е открита
ffmpeg2theora: 命令找不到
ffmpeg2theora: コマンドが見つかりません