MotionBox

Example of feeding data from Motion into a PyGame window to display the coordinates.

To run the program, you start motion, configured to output coordinate data (see motionbox.conf in the zip), then pipe the results to python. NB: the use of the -u option to make python run "unbuffered".

motion -c motionbox.conf | python -u motionbox.py

#!/usr/bin/python

import sys
import pygame
from pygame.locals import *
from pygame.time import Clock
from time import sleep
import thread

def main():
	(mx, my, mw, mh) = (10, 10, 50, 50)
	pygame.init()
	# screen = pygame.display.set_mode((640, 480), FULLSCREEN, 32)
	screen = pygame.display.set_mode((640, 480), 0, 32)
	pygame.display.set_caption("motionbox")
	clock = Clock()
	while True:
		# TIMING
		clock.tick(30)
		
		# PROCESS EVENTS
		for event in pygame.event.get():
			if event.type==QUIT or \
			(event.type == KEYDOWN and event.key == K_ESCAPE):
				sys.exit()
			elif event.type == USEREVENT:
				# print event
				mx = event.x
				my = event.y
				mw = event.w
				mh = event.h
				# adjust mx, my (as they are a center point)
				mx -= mw/2
				my -= mh/2
		
		screen.fill((0, 0, 0))
		# draw rectangle using current position & size
		pygame.draw.rect(screen, (255, 255, 255), (mx, my, mw, mh), 1)
		
		pygame.display.update()
		# sleep(0.01)

# start pygame in a separate thread
# starting a thread is like running a program with & on the shell
thread.start_new_thread(main, ())

# READ INFO FROM STDIN
while 1:
	line = sys.stdin.readline()
	if (not line): break
	line = line.strip()
	if line.startswith("motion"):
		# print "read motion data:", line
		(x, y, w, h, numpixels) = [int(x) for x in line.split()[1:]]
		evt = pygame.event.Event(USEREVENT, {"x" : x, "y": y, "w":w, "h":h})
		pygame.event.post(evt)