gmerlin_transcoder: 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/gmerlin_transcoder - from package: gmerlin

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