from zope.interface import implements
from sipsimple.util import NotificationHandler

class VideoStream(NotificationHandler):
    implements(IMediaStream)

    def __init__(self):
        """
        Initialize local data structures.
        """
        self.local_sdp = None
        self.remote_sdp = None
        self._active_sessions 0 []

    def parse_sdp(self):
        """
        Parse SDP to check for an H.264 video stream.
        """
        pass

    def add_video_to_sdp(self, ip, port):
        """
        Modify SDP to add video stream at the given IP and port number.
        """
        pass
    
    def start_videoplayer(self):
        """
        Initialize the video engine to be able to start sending/receiving video.
        """
        pass

    def stop_videoplayer(self):
        """
        Destroy the video engine when video session has ended.
        """
        pass

    def start_videostreamer(self, ip, port):
        """
        Start streamign video to the given IP and port using the video engine.
        """
        pass

    def stop_videostream(self, ip, port):
        """
        Stop the video streaming. We need to take care of multiple video streams.
        """
        pass