YUV422ItoYUV420I: 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/YUV422ItoYUV420I - from package: dirac

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

Error in other languages:
YUV422ItoYUV420I: bevel nie gevind nie
YUV422ItoYUV420I: comandă negăsită
YUV422ItoYUV420I: comando não encontrado
YUV422ItoYUV420I: commande introuvable
YUV422ItoYUV420I: command not found
YUV422ItoYUV420I: käsku ei ole
YUV422ItoYUV420I: không tìm thấy lệnh
YUV422ItoYUV420I: komanda nerasta
YUV422ItoYUV420I: Kommando nicht gefunden.
YUV422ItoYUV420I: kommandot finns inte
YUV422ItoYUV420I: komut yok
YUV422ItoYUV420I: nie znaleziono polecenia
YUV422ItoYUV420I: níor aimsíodh an t-ordú
YUV422ItoYUV420I: no se encontró la orden
YUV422ItoYUV420I: no s'ha trobat l'ordre
YUV422ItoYUV420I: opdracht niet gevonden
YUV422ItoYUV420I: parancs nem található
YUV422ItoYUV420I: perintah tidak ditemukan
YUV422ItoYUV420I: príkaz nenájdený
YUV422ItoYUV420I: příkaz nenalezen
YUV422ItoYUV420I: команда не найдена
YUV422ItoYUV420I: командата не е открита
YUV422ItoYUV420I: 命令找不到
YUV422ItoYUV420I: コマンドが見つかりません