Pi camera is now persistent in StreamingCamera (a7598c5e) · Commits · OpenFlexure / openflexure-microscope-server

openflexure_microscope/camera/base.py

+13 −7

Original line number	Diff line number	Diff line
		@@ -106,6 +106,15 @@ class BaseCamera(object):
		# Stop worker thread
		self.stop_worker()

		def wait_for_camera(self, timeout=5):
		"""Wait for camera object, with 5 second timeout."""
		timeout_time = time.time() + timeout
		while not self.camera:
		if time.time() > timeout_time:
		raise TimeoutError("Timeout waiting for camera")
		else:
		pass

		# START AND STOP WORKER THREAD

		def start_worker(self, timeout: int=5) -> bool:
		@@ -131,6 +140,7 @@ class BaseCamera(object):

		def stop_worker(self, timeout: int=5) -> bool:
		"""Flags worker thread for stop. Waits for thread to close, or times out."""
		logging.debug("Stopping worker thread")
		timeout_time = time.time() + timeout

		self.stop = True
		@@ -200,9 +210,7 @@ class BaseCamera(object):
		def _thread(self):
		"""Camera background thread."""
		self.frames_iterator = self.frames()

		# Update state
		self.state['stream_active'] = True
		logging.debug("Entering worker thread.")

		for frame in self.frames_iterator:
		self.frame = frame
		@@ -217,15 +225,13 @@ class BaseCamera(object):

		try:
		if self.stop is True:
		logging.debug("Worker thread flagged for stop.")
		self.frames_iterator.close()
		break

		except AttributeError:
		pass

		logging.debug("BaseCamera worker thread exiting...")
		# Reset thread
		self.thread = None
		# Destroy any stored camera object (used especially for handling Pi cameras)
		self.camera = None
		# Update state
		self.state['stream_active'] = False
		No newline at end of file

openflexure_microscope/camera/pi.py

+95 −63

Original line number	Diff line number	Diff line
		@@ -59,6 +59,8 @@ class StreamingCamera(BaseCamera):
		"""Raspberry Pi camera implementation of StreamingCamera."""
		# Run BaseCamera init
		BaseCamera.__init__(self)
		# Attach to Pi camera
		self.camera = picamera.PiCamera()

		# Camera settings
		self.settings.update({
		@@ -83,7 +85,11 @@ class StreamingCamera(BaseCamera):

		def close(self):
		"""Close the Raspberry Pi StreamingCamera"""
		BaseCamera.close(self) # Run BaseCamera close method
		# Run BaseCamera close method
		BaseCamera.close(self)
		# Detatch Pi camera
		if self.camera:
		self.camera.close()

		# HANDLE SETTINGS

		@@ -96,7 +102,16 @@ class StreamingCamera(BaseCamera):
		"""Open config_picamera.yaml file and write to camera."""
		global DEFAULT_CONFIG

		self.start_worker()
		paused_stream = False

		if not self.state['record_active']: # If not recording a video

		#self.start_worker()

		if self.state['stream_active']: # If stream is active
		logging.info("Pausing stream to update settings.")
		self.pause_stream_for_capture() # Pause stream
		paused_stream = True # Remember to unpause stream when done

		if not config_path:
		config = load_config(DEFAULT_CONFIG)
		@@ -140,9 +155,16 @@ class StreamingCamera(BaseCamera):
		if 'digital_gain' in config:
		set_digital_gain(self.camera, config['digital_gain'])

		if paused_stream: # If stream was paused to update settings
		logging.info("Resuming stream.")
		self.resume_stream_for_capture()

		else:
		raise Exception("Cannot update camera settings while recording is active.")

		def change_zoom(self, zoom_value: int=1) -> None:
		"""Change the camera zoom, handling recentering and scaling."""
		self.start_worker()
		#self.start_worker()

		zoom_value = float(zoom_value)
		if zoom_value < 1:
		@@ -165,7 +187,7 @@ class StreamingCamera(BaseCamera):

		def start_preview(self) -> bool:
		"""Start the onboard GPU camera preview."""
		self.start_worker()
		#self.start_worker()

		self.camera.start_preview()
		self.state['preview_active'] = True
		@@ -173,7 +195,7 @@ class StreamingCamera(BaseCamera):

		def stop_preview(self) -> bool:
		"""Stop the onboard GPU camera preview."""
		self.start_worker()
		#self.start_worker()

		self.camera.stop_preview()
		self.state['preview_active'] = False
		@@ -202,7 +224,7 @@ class StreamingCamera(BaseCamera):

		# Start recording method only if a current recording is not running
		if not self.state['record_active']:
		self.start_worker()
		#self.start_worker()

		# If no target is specified, store to StreamingCamera
		if not target:
		@@ -319,7 +341,7 @@ class StreamingCamera(BaseCamera):
		(default 'h264')
		resize ((int, int)): Resize the captured image.
		"""
		self.start_worker()
		#self.start_worker()

		# If no target is specified, store to StreamingCamera
		if not target:
		@@ -367,7 +389,7 @@ class StreamingCamera(BaseCamera):
		use_video_port (bool): Capture from the video port used for streaming (lower resolution, faster)
		resize ((int, int)): Resize the captured image.
		"""
		self.start_worker()
		#self.start_worker()

		if use_video_port:
		resolution = self.settings['video_resolution']
		@@ -415,24 +437,28 @@ class StreamingCamera(BaseCamera):
		# Run this initialisation method
		self.initialisation()

		with picamera.PiCamera() as self.camera:
		# Let camera warm up
		time.sleep(0.1)
		self.wait_for_camera()

		# Settings config
		self.update_settings()
		# Set stream resolution
		self.camera.resolution = self.settings['video_resolution']

		# streaming
		# Create stream
		self.stream = io.BytesIO()

		# start recording on video splitter port 1
		# Start recording on video splitter port 1
		self.camera.start_recording(
		self.stream,
		format='mjpeg',
		quality=self.settings['jpeg_quality'],
		splitter_port=1)

		# Update state
		logging.debug("STREAM ACTIVE")
		self.state['stream_active'] = True

		try: # While the iterator is not closed
		while True:
		# reset stream for next frame
		self.stream.seek(0)
		@@ -441,8 +467,14 @@ class StreamingCamera(BaseCamera):
		time.sleep(1/self.settings['framerate']*0.1)
		# yield the result to be read
		frame = self.stream.getvalue()

		# ensure the size of package is right
		if len(frame) == 0:
		pass
		else:
		yield frame
		finally: # When GeneratorExit or StopIteration raised, run cleanup code
		logging.debug("Stopping stream recording on port 1")
		self.camera.stop_recording(splitter_port=1)
		self.state['stream_active'] = False
		logging.debug("FRAME ITERATOR END")

tests/test_camera.py

+32 −44

Original line number	Diff line number	Diff line
		@@ -26,16 +26,6 @@ success_string = """
		"""


		def wait_for_cam(camera, timeout=5):
		"""Wait for camera object in global namespace, with 5 second timeout."""
		timeout_time = time.time() + timeout
		while not camera:
		if time.time() > timeout_time:
		raise TimeoutError("Timeout waiting for camera")
		else:
		pass


		class TestCaptureMethods(unittest.TestCase):

		def test_still_capture(self):
		@@ -46,7 +36,7 @@ class TestCaptureMethods(unittest.TestCase):
		for resize in [None, (640, 480)]:

		# Wait for camera
		wait_for_cam(camera)
		camera.wait_for_camera()

		# Capture to a context (auto-deletes files when done)
		with camera.capture(
		@@ -114,7 +104,7 @@ class TestCaptureMethods(unittest.TestCase):
		for use_video_port in [True, False]:
		for resize in [None, (640, 480)]:
		# Wait for camera
		wait_for_cam(camera)
		camera.wait_for_camera()

		# Capture
		stream = camera.capture(
		@@ -151,7 +141,7 @@ class TestUnencodedMethods(unittest.TestCase):
		print("{}, {}, {}".format(id, resize, use_video_port))

		# Wait for camera
		wait_for_cam(camera)
		camera.wait_for_camera()

		# Capture RGB array
		yuv = camera.array(
		@@ -183,7 +173,7 @@ class TestUnencodedMethods(unittest.TestCase):
		print("{}, {}, {}".format(id, resize, use_video_port))

		# Wait for camera
		wait_for_cam(camera)
		camera.wait_for_camera()

		# Capture RGB array
		rgb = camera.array(
		@@ -216,7 +206,7 @@ class TestRecordMethods(unittest.TestCase):
		for write_to_file in [True, False, None]:

		# Wait for camera
		wait_for_cam(camera)
		camera.wait_for_camera()

		# Start recording
		with camera.start_recording(
		@@ -249,7 +239,7 @@ class TestRecordMethods(unittest.TestCase):
		global camera

		# Wait for camera
		wait_for_cam(camera)
		camera.wait_for_camera()

		# Start recording
		stream = camera.start_recording()
		@@ -270,32 +260,30 @@ class TestRecordMethods(unittest.TestCase):


		class TestThreadStarting(unittest.TestCase):
		def test_capture_restarting_stream(self):
		def test_restarting_stream(self):
		"""Tests that a capture call restarts the camera worker thread."""
		global camera

		# Wait for camera
		wait_for_cam(camera)
		camera.wait_for_camera()

		# Force-stop the camera worker thread (should return True)
		self.assertTrue(camera.stop_worker())

		# Check Pi camera has been disconnected
		self.assertFalse(camera.camera)
		self.assertTrue(camera.camera)
		self.assertFalse(camera.thread)

		# Restart worker thread by initialising a capture
		with camera.capture(
		use_video_port=True) as stream:
		# Restart worker thread
		self.assertTrue(camera.start_worker())

		# Ensure StreamObject 'stream' has
		# a valid BytesIO object and byte string
		self.assertTrue(isinstance(stream.data, io.IOBase))
		self.assertTrue(isinstance(stream.binary, (bytes, bytearray)))
		self.assertTrue(camera.camera)
		self.assertTrue(camera.thread)
		self.assertIsInstance(camera.stream, io.IOBase)


		if __name__ == '__main__':
		camera = None
		with StreamingCamera() as camera:
		camera = StreamingCamera()

		suites = [
		unittest.TestLoader().loadTestsFromTestCase(TestCaptureMethods),