text: Title: Create infinite stream from image
  Body: Hello! can someone tell me how i can make an endless stream from one picture? this picture may change over time
  there is my code:
  ```
  def loop_image():
          img = cv2.imread('./images/1.jpg')
          img = cv2.resize(img, (640, 480))
          new_frame = VideoFrame.from_ndarray(img, format="bgr24")
          return new_frame
  
  class VideoStreamTrack(VideoStreamTrack):
      def __init__(self):
          super().__init__()  # don't forget this!
          self.counter = 0
          self.frames = []
          for i in range(3):
              print(f"append image {i}")
              self.frames.append(loop_image())
  
      async def recv(self):
          print("append image")
          pts, time_base = await self.next_timestamp()
          frame = self.frames[self.counter % 30]
          frame.pts = pts
          frame.time_base = time_base
          self.counter += 1
  
          self.frames.append(loop_image())
          return frame
  ```