sec2ts: 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/sec2ts - from package: opencaster

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

Error in other languages:
sec2ts: bevel nie gevind nie
sec2ts: comandă negăsită
sec2ts: comando não encontrado
sec2ts: commande introuvable
sec2ts: command not found
sec2ts: käsku ei ole
sec2ts: không tìm thấy lệnh
sec2ts: komanda nerasta
sec2ts: Kommando nicht gefunden.
sec2ts: kommandot finns inte
sec2ts: komut yok
sec2ts: nie znaleziono polecenia
sec2ts: níor aimsíodh an t-ordú
sec2ts: no se encontró la orden
sec2ts: no s'ha trobat l'ordre
sec2ts: opdracht niet gevonden
sec2ts: parancs nem található
sec2ts: perintah tidak ditemukan
sec2ts: príkaz nenájdený
sec2ts: příkaz nenalezen
sec2ts: команда не найдена
sec2ts: командата не е открита
sec2ts: 命令找不到
sec2ts: コマンドが見つかりません