GPIO combine with OMX Player to play different videos when triggered

Question

I have a simple project where I want to combine a motion sensor to play certain video files. So normally in an infinitive loop I want to play a flickering video and if the motion sensor is triggered I want to stop the flickering video and select a scary one. See the following code.

import RPi.GPIO as GPIO
import time
from omxplayer.player import OMXPlayer
from random import randint

#
def main():
    GPIO.setmode(GPIO.BCM)
    GPIO.setup(17,GPIO.IN)

    flicks = ("/home/pi/halloween/flicks/tv_noise_1.mp4")
    scares = ("/home/pi/halloween/scares/tv_noise_kitten_zombie_2.mp4")

    omxc = OMXPlayer(flicks)
    state = 0 # set initial state as 0
    while True:
        i = GPIO.input(17)
        if(not omxc.is_playing()):
            omxc = OMXPlayer(flicks)
        if(state != i): # change in state detected
            omxc.quit()
            omxc = OMXPlayer(scares)
            time.sleep(35) # wait as long as this video lasts

        state = i

if __name__ == '__main__':
    main() 

However, I keep getting the error:

Traceback (most recent call last):
  File "scare_old.py", line 29, in <module>
    main()
  File "scare_old.py", line 20, in main
    if(not omxc.is_playing()):
  File "<decorator-gen-90>", line 2, in is_playing
  File "/home/pi/.local/lib/python2.7/site-packages/omxplayer/player.py", line 48, in wrapped
    raise OMXPlayerDeadError('Process is no longer alive, can\'t run command')
omxplayer.player.OMXPlayerDeadError: Process is no longer alive, can't run command

What exactly is the problem? I mean the process should run because I'm just starting it before?

Answer 1

import RPi.GPIO as GPIO
import time
from random import randint
from subprocess import Popen, PIPE
import os
import logging

logger = logging.getLogger(__name__)

class Player:
def __init__(self, movie):
    self.movie = movie
    self.process = None

def start(self):
    self.stop()
    self.process = Popen(['omxplayer', self.movie], stdin=PIPE,
    stdout=open(os.devnull, 'r+b', 0), close_fds=True, bufsize=0)
    self.process.stdin.write("b") # start playing

def stop(self):
    p = self.process
    if p is not None:
        try:
            p.stdin.write("q") # send quit command
            p.terminate()
            p.wait() # -> move into background thread if necessary
        except EnvironmentError as e:
            logger.error("can't stop %s: %s", self.movie, e)

def main():
GPIO.setmode(GPIO.BCM)
GPIO.setup(17,GPIO.IN)

first = ("/home/pi/halloween/flicks/tv_noise_no_sound_short_1.mp4")
second = ("/home/pi/halloween/scares/tv_noise_the_ring_2.mp4")

first_player = Player(movie=first)
second_player = Player(movie=second)

second_player.start()
second_player.stop()

first_player.start()
print "start the first/standard clip"

state = GPIO.input(17)  # get the initial state of PIR
while True:
    i = GPIO.input(17)
    if((first_player.process.poll() is not None) and (second_player.process.poll() is not None)):
            print "restart flickering video"
            first_player.stop()
            second_player.stop()
            first_player.start()
    if(state != i): # change in state detected
        print "state has changed"
        print "scaring video played"
        if(second_player.process.poll() is not None):
            first_player.stop()
            second_player.start()
    state = i

if __name__ == '__main__':
    main()