Thread exception while closing stream #111
Description
Hi,
I'm using imutils to capture video stream from a Pi Camera on a Raspberry 3 B+ with Raspbian.
I have a function processing the frames and everything works fine until I press CTRL+C to interrupt the script. In that case, sometimes I receive these errors:
Exception in thread Thread-1:
Traceback (most recent call last):
File "/usr/lib/python2.7/threading.py", line 801, in __bootstrap_inner
self.run()
File "/usr/lib/python2.7/threading.py", line 754, in run
self.__target(*self.__args, **self.__kwargs)
File "/usr/local/lib/python2.7/dist-packages/imutils/video/pivideostream.py", line 42, in update
self.camera.close()
File "/usr/local/lib/python2.7/dist-packages/picamera/camera.py", line 745, in close
self._splitter.close()
File "/usr/local/lib/python2.7/dist-packages/picamera/mmalobj.py", line 2400, in close
self.disconnect()
File "/usr/local/lib/python2.7/dist-packages/picamera/mmalobj.py", line 2439, in disconnect
self.inputs[0].disconnect()
File "/usr/local/lib/python2.7/dist-packages/picamera/mmalobj.py", line 1311, in disconnect
self.connection.close()
File "/usr/local/lib/python2.7/dist-packages/picamera/mmalobj.py", line 2161, in close
super(MMALConnection, self).close()
TypeError: super() argument 1 must be type, not None
while sometimes I receive this different error:
Traceback (most recent call last):
File "_ctypes/callbacks.c", line 315, in 'calling callback function'
File "/usr/local/lib/python2.7/dist-packages/picamera/mmalobj.py", line 1227, in wrapper
self._pool.send_buffer(block=False)
File "/usr/local/lib/python2.7/dist-packages/picamera/mmalobj.py", line 1931, in send_buffer
super(MMALPortPool, self).send_buffer(port, block, timeout)
File "/usr/local/lib/python2.7/dist-packages/picamera/mmalobj.py", line 1882, in send_buffer
port.send_buffer(buf)
File "/usr/local/lib/python2.7/dist-packages/picamera/mmalobj.py", line 1166, in send_buffer
prefix="cannot send buffer to port %s" % self.name)
File "/usr/local/lib/python2.7/dist-packages/picamera/exc.py", line 183, in mmal_check
if status != mmal.MMAL_SUCCESS:
AttributeError: 'NoneType' object has no attribute 'MMAL_SUCCESS'
Traceback (most recent call last):
File "_ctypes/callbacks.c", line 315, in 'calling callback function'
File "/usr/local/lib/python2.7/dist-packages/picamera/mmalobj.py", line 1220, in wrapper
buf = MMALBuffer(buf)
TypeError: 'NoneType' object is not callable
Exception in thread Thread-1:
Traceback (most recent call last):
File "/usr/lib/python2.7/threading.py", line 801, in __bootstrap_inner
self.run()
File "/usr/lib/python2.7/threading.py", line 754, in run
self.__target(*self.__args, **self.__kwargs)
File "/usr/local/lib/python2.7/dist-packages/imutils/video/pivideostream.py", line 31, in update
for f in self.stream:
File "/usr/local/lib/python2.7/dist-packages/picamera/camera.py", line 1710, in capture_continuous
encoder.close()
File "/usr/local/lib/python2.7/dist-packages/picamera/encoders.py", line 431, in close
self.stop()
File "/usr/local/lib/python2.7/dist-packages/picamera/encoders.py", line 416, in stop
self.parent._stop_capture(self.camera_port)
File "/usr/local/lib/python2.7/dist-packages/picamera/camera.py", line 529, in _stop_capture
port.params[mmal.MMAL_PARAMETER_CAPTURE] = False
AttributeError: 'NoneType' object has no attribute 'MMAL_PARAMETER_CAPTURE'
It seems related to the thread handling the stream in PiVideoStream, where some objects should not be None when they are called after the capture has been interrupted.
This is the outline of my script, where I need to do some cleanup and final stuff after the loop is interrupted.
# initialization
stream = VideoStream(usePiCamera=True).start()
try:
while True:
result = process(stream.read())
except KeyboardInterrupt:
stream.stop()
# CLEANUP CODE
Is there something I am missing?
Thanks in advance,
Best regards