dvbstream: 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/dvbstream - from package: dvbstream

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