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pythonwhile-loopraspbianraspberry-pi3

python How can I stop an infinite while loop and continue with rest of code?


The problem is that I can not exit the while loop without stopping the entire program.

When I execute the code on my Raspberry Pi, the camera starts recording, but when I want to end the video and press Ctrl+c, the entire program stops instead of continuing after the while loop. I thought the signal handler would catch the keyboard interrupt but it does not.

My code:

import picamera
import signal
from time import sleep
from subprocess import call

def signal_handler(signal, frame):
        global interrupted
        interrupted = True

signal.signal(signal.SIGINT, signal_handler)

interrupted = False

# Setup the camera
with picamera.PiCamera() as camera:
    camera.resolution = (1640, 922)
    camera.framerate = 30

    # Start recording
    camera.start_recording("pythonVideo.h264")

while True:
        sleep(0.5)
        print("still recording")

        if interrupted:
                print("Ctrl+C pressed")
                camera.stop_recording()
                break

# Stop recording
#camera.stop_recording()

# The camera is now closed.

print("We are going to convert the video.")
# Define the command we want to execute.
command = "MP4Box -add pythonVideo.h264 convertedVideo.mp4 -fps 30"
#Execute command.
call([command], shell=True)
# Video converted.
print("Video converted.")

What I tried:

bflag = True
while bflag ==True:
        sleep(0.5)
        print("still recording")

        if interrupted:
                print("Ctrl+C pressed")
                camera.stop_recording()
                bflag = False

Error:

pi@raspberrypi:~/Documents/useThisFolder $ python cookieVideo.py 
still recording
still recording
still recording
still recording
still recording
^Cstill recording
Ctrl+C pressed
Traceback (most recent call last):
  File "cookieVideo.py", line 29, in <module>
    camera.stop_recording()
  File "/usr/lib/python2.7/dist-packages/picamera/camera.py", line 1193, in stop_recording
'port %d' % splitter_port)
picamera.exc.PiCameraNotRecording: There is no recording in progress on port 1

Solution

  • This would do it:

    while True:
        try:
            sleep(0.5)
            print("still recording")
        except KeyboardInterrupt:
            print("Ctrl+C pressed")
            camera.stop_recording()
            break