An untested experimental program to stream files one packet at a time, with a pause feature. This will certainly be very slow if it works at all.

opencaster-pauser.py

#!/usr/local/bin/env python

import signal
import sys

packet_size = 188
position = 0
paused = False

def pause_handler(signal, frame):
  paused = not paused

signal.signal(signal.SIGINT, pause_handler)

infile = sys.stdin.buffer
outfile = sys.stdout.buffer
data = infile.read(packet_size)
position += 1
while data:
  if paused:
    signal.pause() # sleep until any signal is received
    outfile.write(data)
    data = infile.read(packet_size)
    position += 1