async def recv(self):
        """
        Receive the next :class:`~av.video.frame.VideoFrame`.

        The base implementation just reads a 640x480 green frame at 30fps,
        subclass :class:`VideoStreamTrack` to provide a useful implementation.
        """
        pts, time_base = await self.next_timestamp()

        frame = VideoFrame(width=640, height=480)
        for p in frame.planes:
            p.update(bytes(p.buffer_size))
        frame.pts = pts
        frame.time_base = time_base
        return frame