class VideoStream:
	"""
	Interface to provide easy iteration and indexing access to imageio
	video objects:
	self[10] returns the 10^th frame of the video.
	self[10:20] returns frames 10-20 as a list
	"""
	def __init__(self, file:str, color:bool=True):
		"""
		file : str
			uri of video file
		color : bool
			Pass true for VideoStream to return color images. Pass false
			for VideoStream to return b+w images. Defaults to True.
		"""
		self.video = imageio.get_reader(file,  'ffmpeg')
		self.color = color

		self.duration = self.video.get_meta_data()['duration']
		self.fps = self.video.get_meta_data()['fps']
		self.nframes = self.video.get_meta_data()['nframes']
		if self.color:
			self.shape = (*self.video.get_meta_data()['size'][::-1], 3)
		else:
			self.shape = (*self.video.get_meta_data()['size'][::-1], 1)

		self.index = 0

	def __len__(self):
		"""
		Returns number of frames in video.
		"""
		return self.nframes

	def __getitem__(self, index):
		"""
		Returns single frame if index is int or a list of frames if index is a slice.
		"""
		if isinstance(index, slice):
			indices = range(*index.indices(len(self)))
			return (self._get_frame(i) for i in indices)
		else:
			return self._get_frame(index)

	def __next__(self):
		if self.index >= len(self):
			raise StopIteration
		else:
			self.index += 1
			return self.__getitem__(self.index-1)

	def __iter__(self):
		return self

	def _get_frame(self, index:int):
		frame = self.video.get_data(index)
		if self.color:
			return frame
		else:
			return color.rgb2gray(frame)

	def set_color(self, color:bool):
		"""
		color : bool
			Pass true for VideoStream to return color images. Pass false
			for VideoStream to return b+w images.
		"""
		self.color = color