avg_chromakey: 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/avg_chromakey - from package: python-libavg

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

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