flvmeta: 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/flvmeta - from package: flvmeta

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