Merge pull request #116 from timwelch/dev

Adding support for v4l2 devices directly in python

src/cli/add.py

@@ -95,11 +95,13 @@ insert_model = {
 
 # Check if the user explicitly set ffmpeg as recorder
 if config.get("video", "recording_plugin") == "ffmpeg":
-	from ffmpeg_reader import ffmpeg_reader
-
 	# Set the capture source for ffmpeg
+	from ffmpeg_reader import ffmpeg_reader
 	video_capture = ffmpeg_reader(config.get("video", "device_path"), config.get("video", "device_format"))
-
+elif config.get("video", "recording_plugin") == "pyv4l2":
+	# Set the capture source for pyv4l2
+	from pyv4l2_reader import pyv4l2_reader
+	video_capture = pyv4l2_reader(config.get("video", "device_path"), config.get("video", "device_format"))
 else:
 	# Start video capture on the IR camera through OpenCV
 	video_capture = cv2.VideoCapture(config.get("video", "device_path"))

src/compare.py

@@ -107,11 +107,13 @@ timings["ic"] = time.time()
 
 # Check if the user explicitly set ffmpeg as recorder
 if config.get("video", "recording_plugin") == "ffmpeg":
-	from ffmpeg_reader import ffmpeg_reader
-
 	# Set the capture source for ffmpeg
+	from ffmpeg_reader import ffmpeg_reader
 	video_capture = ffmpeg_reader(config.get("video", "device_path"), config.get("video", "device_format"))
-
+elif config.get("video", "recording_plugin") == "pyv4l2":
+	# Set the capture source for pyv4l2
+	from pyv4l2_reader import pyv4l2_reader
+	video_capture = pyv4l2_reader(config.get("video", "device_path"), config.get("video", "device_format"))
 else:
 	# Start video capture on the IR camera through OpenCV
 	video_capture = cv2.VideoCapture(config.get("video", "device_path"))

src/pyv4l2_reader.py

@@ -0,0 +1,110 @@
+# Class that simulates the functionality of opencv so howdy can use v4l2 devices seamlessly
+
+# Import required modules. lib4l-dev package is also required.
+import v4l2
+import fcntl
+import numpy
+import sys
+from cv2 import cvtColor, COLOR_GRAY2BGR, CAP_PROP_FRAME_WIDTH, CAP_PROP_FRAME_HEIGHT
+
+try:
+	from pyv4l2.frame import Frame
+except ImportError:
+	print("Missing pyv4l2 module, please run:")
+	print(" pip3 install pyv4l2\n")
+	sys.exit(13)
+
+class pyv4l2_reader:
+	""" This class was created to look as similar to the openCV features used in Howdy as possible for overall code cleanliness. """
+
+	# Init
+	def __init__(self, device_name, device_format):
+		self.device_name = device_name
+		self.device_format = device_format
+		self.height = 0
+		self.width = 0
+		self.probe()
+		self.frame = ""
+
+	def set(self, prop, setting):
+		""" Setter method for height and width """
+		if prop == CAP_PROP_FRAME_WIDTH:
+			self.width = setting
+		elif prop == CAP_PROP_FRAME_HEIGHT:
+			self.height = setting
+
+	def get(self, prop):
+		""" Getter method for height and width """
+		if prop == CAP_PROP_FRAME_WIDTH:
+			return self.width
+		elif prop == CAP_PROP_FRAME_HEIGHT:
+			return self.height
+			
+	def probe(self):
+		""" Probe the video device to get height and width info """
+
+		vd = open(self.device_name, 'r')
+		fmt = v4l2.v4l2_format()
+		fmt.type = v4l2.V4L2_BUF_TYPE_VIDEO_CAPTURE
+		ret = fcntl.ioctl(vd, v4l2.VIDIOC_G_FMT, fmt)
+		vd.close()
+		if ret == 0:
+			height = fmt.fmt.pix.height
+			width = fmt.fmt.pix.width
+		else: 
+			# Could not determine the resolution from ioctl call. Reverting to slower ffmpeg.probe() method
+			import ffmpeg
+			probe = ffmpeg.probe(self.device_name)
+			height = int(probe['streams'][0]['height'])
+			width = int(probe['streams'][0]['width'])
+
+		if self.get(CAP_PROP_FRAME_HEIGHT) == 0:
+			self.set(CAP_PROP_FRAME_HEIGHT, int(height))
+
+		if self.get(CAP_PROP_FRAME_WIDTH) == 0:
+			self.set(CAP_PROP_FRAME_WIDTH, int(width))
+
+	def record(self):
+		""" Start recording """
+		self.frame = Frame(self.device_name)
+
+
+	def grab(self):
+		""" Read a sigle frame from the IR camera. """
+		self.read()
+
+	def read(self):
+		""" Read a sigle frame from the IR camera. """
+
+		if not self.frame:
+			self.record() 
+
+		# Grab a raw frame from the camera
+		frame_data = self.frame.get_frame()
+
+		# Convert the raw frame_date to a numpy array
+		img = (
+		   numpy
+		   .frombuffer(frame_data, numpy.uint8)
+		)
+
+		# Convert the numpy array to a proper grayscale image array
+		img_bgr = cvtColor(img, COLOR_GRAY2BGR)
+
+		# Convert the grayscale image array into a proper RGB style numpy array
+		img2 = (
+		   numpy
+		   .frombuffer(img_bgr, numpy.uint8)
+		   .reshape([352, 352, 3])
+		)
+
+		# Return a single frame of video
+		return 0, img2
+
+	def release(self):
+		""" Empty our array. If we had a hold on the camera, we would give it back here. """
+		self.video = ()
+		self.num_frames_read = 0
+		if self.frame:
+			self.frame.close()
+