avg_jitterfilter: 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 Debian possible default full paths are:

/usr/bin/avg_jitterfilter - from package: python-libavg

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