Camera not closing properly after successful run #847
Description
Describe what you want to implement and what the issue & the steps to reproduce it are:
I'm aiming to capture and save image frames in a continuously updating fixed size queue
When calling my script buffer.py the camera frames are successfully grabbed and displayed, but when I escape an error is thrown:
"Error stopping grabbing: Node not existing (file 'genicam_wrap.cpp', line 16822)"
The next time I run the script the code does not run and a persistent error comes up:
"pure virtual method called
terminate called without an active exception
Aborted (core dumped)"
I'm thinking it's because some module is not being closed properly, but I'm not sure where or how
with SafePylonCamera() as cam:
print(f"{fps} FPS at {res_width}x{res_height}")
cam.start_grabbing()
# --------------------- OUTPUT FOLDER SETUP ---------------------
buffer_folder = "./buffer"
if os.path.isdir(buffer_folder):
shutil.rmtree(buffer_folder)
os.makedirs(buffer_folder)
# ---------------------------------------------------------------
prev_time = time.time()
og_time = prev_time
while cam.is_grabbing():
cur_time = time.time()
print(f'Camera running at {round(1.0/(cur_time - prev_time),1)} frames per second')
frame = cam.retrieve_frame((cur_time - prev_time) >= 1.0 / fps) #condition passed in; if not time yet, returns None
if frame is not None:
prev_time = cur_time
frame = cv2.resize(frame, (res_width, res_height))
delta = round(time.time() - og_time, 3)
filename = os.path.join(buffer_folder, f"{delta}.png")
cv2.imwrite(filename, frame)
# Maintain buffer size
all_frames = os.listdir(buffer_folder)
ranked_indices = sorted([(float(re.match(r"\d+.\d*", filename).group()),i) for i, filename in enumerate(all_frames)])
if len(all_frames) > length:
os.remove(os.path.join(buffer_folder, all_frames[ranked_indices[0][1]]))
cv2.imshow("Camera", frame)
if cv2.waitKey(1) == 27:
print("----Interrupt via ESC----")
break
else:
print('Missed frame')
class SafePylonCamera:
def __init__(self, strategy=pylon.GrabStrategy_LatestImageOnly, timeout=5000):
self.camera = None
self.converter = None
self.strategy = strategy
self.timeout = timeout
self._grabbing = False
# Register cleanup
atexit.register(self.close)
signal.signal(signal.SIGINT, self._signal_handler)
signal.signal(signal.SIGTERM, self._signal_handler)
def open(self):
self.camera = pylon.InstantCamera(pylon.TlFactory.GetInstance().CreateFirstDevice())
self.camera.Open()
self.converter = pylon.ImageFormatConverter()
self.converter.OutputPixelFormat = pylon.PixelType_BGR8packed
self.converter.OutputBitAlignment = pylon.OutputBitAlignment_MsbAligned
print("[SafePylonCamera] Camera opened.")
def start_grabbing(self):
if self.camera and not self._grabbing:
self.camera.StartGrabbing(self.strategy)
self._grabbing = True
print("[SafePylonCamera] Started grabbing.")
def retrieve_frame(self,condition):
if condition and self.camera and self._grabbing:
result = self.camera.RetrieveResult(self.timeout, pylon.TimeoutHandling_ThrowException)
if result.GrabSucceeded():
image = self.converter.Convert(result)
frame = image.GetArray()
result.Release()
return frame
result.Release()
return None
def is_grabbing(self):
return self.camera and self._grabbing and self.camera.IsGrabbing()
def stop_grabbing(self):
if self.camera and self.camera.IsGrabbing():
self.camera.StopGrabbing()
print("[SafePylonCamera] Stopped grabbing.")
self._grabbing = False
def close(self):
if self.camera:
self.stop_grabbing()
if self.camera.IsOpen():
self.camera.Close()
print("[SafePylonCamera] Camera closed.")
self.camera = None
cv2.destroyAllWindows()
gc.collect()
def _signal_handler(self, sig, frame):
print(f"\n[SafePylonCamera] Signal {sig} received. Cleaning up.")
self.close()
sys.exit(0)
def __enter__(self):
self.open()
return self
def __exit__(self, exc_type, exc_val, exc_tb):
self.close()
Is your camera operational in Basler pylon viewer on your platform
Yes
Hardware setup used
Basler is connected via USB to a GMKtec Nuc running Ubuntu OS
Camera(s) used
to be updated
Runtime information:
to be updated