rpi_video_looper/hello_video.py
2015-02-10 17:34:46 -08:00

70 lines
2.6 KiB
Python

# Copyright 2015 Adafruit Industries.
# Author: Tony DiCola
# License: GNU GPLv2, see LICENSE.txt
import os
import subprocess
import time
class HelloVideoPlayer(object):
def __init__(self, config):
"""Create an instance of a video player that runs hello_video.bin in the
background.
"""
self._process = None
self._load_config(config)
def _load_config(self, config):
self._extensions = config.get('hello_video', 'extensions') \
.translate(None, ' \t\r\n.') \
.split(',')
def supported_extensions(self):
"""Return list of supported file extensions."""
return self._extensions
def play(self, movie, loop=False):
"""Play the provided movied file, optionally looping it repeatedly."""
self.stop(3) # Up to 3 second delay to let the old player stop.
# Assemble list of arguments.
args = ['hello_video.bin']
if loop:
args.append('--loop') # Add loop parameter if necessary.
args.append(movie) # Add movie file path.
# Run hello_video process and direct standard output to /dev/null.
self._process = subprocess.Popen(args,
stdout=open(os.devnull, 'wb'),
close_fds=True)
def is_playing(self):
"""Return true if the video player is running, false otherwise."""
if self._process is None:
return False
self._process.poll()
return self._process.returncode is None
def stop(self, block_timeout_sec=None):
"""Stop the video player. block_timeout_sec is how many seconds to
block waiting for the player to stop before moving on.
"""
# Stop the player if it's running.
if self._process is not None and self._process.returncode is None:
# process.kill() doesn't seem to work reliably if USB drive is
# removed, instead just run a kill -9 on it.
subprocess.call(['kill', '-9', str(self._process.pid)])
# If a blocking timeout was specified, wait up to that amount of time
# for the process to stop.
start = time.time()
while self._process is not None and self._process.returncode is None:
if (time.time() - start) >= block_timeout_sec:
break
time.sleep(0)
# Let the process be garbage collected.
self._process = None
def create_player(config):
"""Create new video player based on hello_video."""
return HelloVideoPlayer(config)