#!/bin/bash

pipe=/opt/prod/pipe/ffmpeg

trap "rm -f $pipe" EXIT

# creating the FIFO
[[ -p $pipe ]] || mkfifo $pipe

while true; do
    # can't just use "while read line" if we
    # want this script to continue running.
    read line <$pipe

    # now implementing a bit of security,
    # feel free to improve it.
    # we ensure that the command is a ffmpeg one.
    bash <<<"$line"
done