PiCamera instance variables

[skeltoh]

The example code for capturing video here (https://docs.auto-pi-lot.com/en/latest/guide/quickstart.html) produces an error (I added the name to avoid a warning):

from autopilot.hardware.cameras import PiCamera cam = PiCamera(name='cam') cam.write('test_video.mp4') cam.capture(timed=10)

---

AttributeError Traceback (most recent call last) /tmp/ipykernel_14379/453994599.py in ----> 1 cam.write('test_video.mp4')

~/git/autopilot/autopilot/hardware/cameras.py in write(self, output_filename, timestamps, blosc) 402 self.blosc = blosc 403 self._write_q = mp.Queue() --> 404 self.writer = Video_Writer(self._write_q, output_filename, self.fps, timestamps=timestamps, blosc=blosc) 405 self.writer.start() 406 self.writing.set()

~/git/autopilot/autopilot/hardware/cameras.py in fps(self) 724 int - fps 725 """ --> 726 return self._fps 727 728 @fps.setter

AttributeError: 'PiCamera' object has no attribute '_fps'

If I change the code to

from autopilot.hardware.cameras import PiCamera cam = PiCamera(name='cam') cam._fps = 30 cam.write('test_video.mp4') cam.capture(timed=10)

Then I get:

Exception in thread Thread-8: Traceback (most recent call last): File "/usr/lib/python3.7/threading.py", line 917, in _bootstrap_inner self.run() File "/usr/lib/python3.7/threading.py", line 865, in run self._target(*self._args, **self._kwargs) File "/home/pi/git/autopilot/autopilot/hardware/cameras.py", line 226, in _capture self.capture_init() File "/home/pi/git/autopilot/autopilot/hardware/cameras.py", line 788, in capture_init self._picam_writer = self.PiCamera_Writer(self.resolution, self.format) AttributeError: 'PiCamera' object has no attribute 'format'

If I add:

cam.format = 'rgb'

Then I get:

Exception in thread Thread-8: Traceback (most recent call last): File "/usr/lib/python3.7/threading.py", line 917, in _bootstrap_inner self.run() File "/usr/lib/python3.7/threading.py", line 865, in run self._target(*self._args, *self._kwargs) File "/home/pi/git/autopilot/autopilot/hardware/cameras.py", line 226, in _capture self.capture_init() File "/home/pi/git/autopilot/autopilot/hardware/cameras.py", line 788, in capture_init self._picam_writer = self.PiCamera_Writer(self.resolution, self.format) File "/home/pi/git/autopilot/autopilot/hardware/cameras.py", line 847, in init self.resolution[0]+ 31 // 32 32, TypeError: 'NoneType' object is not subscriptable

If I add:

cam.resolution = (640,480)

Then I get:

---

AttributeError Traceback (most recent call last) /tmp/ipykernel_16972/3992256397.py in 2 cam._fps = 30 3 cam.format = 'rgb' ----> 4 cam.resolution = (640,480)

~/git/autopilot/autopilot/hardware/cameras.py in resolution(self, resolution) 706 def resolution(self, resolution: typing.Tuple[int, int]): 707 self._resolution = resolution --> 708 if self._picam_writer is not None: 709 self._picam_writer.resolution = self._resolution 710 if self.initialized.is_set() and not self.capturing.is_set():

AttributeError: 'PiCamera' object has no attribute '_picam_writer'

At this point, it seems like something strange is going on with getters/setter methods in this class. It seems kind of odd since I see self._picam_writer = None in PiCamera.init.

As a note, I actually had another error before I installed ffmpeg with apt. Maybe that should be added to the setup scripts.

[sneakers-the-rat]

I think I see what's going on here --

the camera module checks if the picamera package is present: https://github.com/wehr-lab/autopilot/blob/d352feef3b8aac8699fbc4c27270580d0a48ab0f/autopilot/hardware/cameras.py#L37-L41

and then if it isn't detected, the PiCamera class bails on initializing: https://github.com/wehr-lab/autopilot/blob/d352feef3b8aac8699fbc4c27270580d0a48ab0f/autopilot/hardware/cameras.py#L655-L657

and an exception is logged but not raised.

So all this that follows & sets up the object doesn't happen, but the object is still created: https://github.com/wehr-lab/autopilot/blob/d352feef3b8aac8699fbc4c27270580d0a48ab0f/autopilot/hardware/cameras.py#L659-L668

Which would explain all the above behavior.

does this fix? https://github.com/wehr-lab/autopilot/commit/9637ec771f4ce181a6b5139a0f8d67eb7d341803

[skeltoh]

Looks like the real problem was I didn't have PiCamera installed, but that bug fix alerts if it isn't. Thanks!