dvb-format-convert: 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 CentOS possible default full paths are:

/usr/bin/dvb-format-convert - from package: v4l-utils

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/dvb-format-convert - from package: dvb-tools

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

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