yuvdenoise: 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/yuvdenoise - from package: mjpegtools

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

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