Unblock write on subprocess.PIPE?

Question

Unblock write on subprocess.PIPE?

I am developing using python for a Raspberry Pi application. I changed the c-program that plays full-screen movies for entering data from FIFO.

Same:

$ ./hello_video.bin test.h264 < .my_fifo
$ echo 3 > .my_fifo

I can send numbers to FIFO, and hello_video.bin starts the corresponding video clip and cyclically terminates it.

The next step should be to make the video possible from the remote control. This is what I have:

#!/usr/bin/env python
import socket
import threading
import Queue
import subprocess
import sys
from time import sleep

host = ''       # empty port = all local ports
port = 5005     
buffer = 2      # small buffer sufficient

player = "/opt/vc/src/hello_pi/hello_video/hello_video.bin"
clip = "/opt/vc/src/hello_pi/hello_video/test.h264"

p = subprocess.Popen([player, clip], stdin=subprocess.PIPE)

class readFromUDPSocket(threading.Thread):

    def __init__(self):
        threading.Thread.__init__(self)

    def run(self):
        while True:
            data,addr = socketUDP.recvfrom(buffer)
            try:
                p.stdin.write(data)
                p.stdin.flush() 

            except:
                pass   


if __name__ == '__main__':

    # Create socket (IPv4 protocol, datagram (UDP)) and bind to address
    socketUDP = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    socketUDP.bind((host, port))

    # Instantiate & start threads
    myServer = readFromUDPSocket()
    myServer.daemon = True
    myServer.start()

while 1:
    pass

UDPSock.close()