5 Replies Latest reply: Oct 27, 2010 2:34 PM by tckitty RSS

    Live TV Delay

    doublenach

      Hi all,

       

      I am considering buying a Slingbox, but before I do, I have a couple of questions. I plan to stream live from my tv to my iPhone, which will be on 3G most of the time. Can anyone tell me what is the delay when streaming to the iPhone?

      The reason I am asking this is because I have tried watching tv on Justin.tv app for iPhone (which uses http for streaming) and the delay is huge, what appears on my phone has already appeared on the TV a minute ago or even more. What protocol does Slingbox uses? Do I have control of the resolution and video bitrate, or is it automatically adjusted based on the bandwitch?

       

      My current approach is a PC connected to the TV, using VLC to stream with the UDP protocol, this works very good, very little, almost no delay, I guess this is because of the UDP protocol... The problem is there's no way to watch fullscreen on the iPhone.

       

       

      Thank you all for your attention,

      Rafael

        • Re: Live TV Delay
          eferz Expert

          Slingbox uses a proprietary streaming technology.  They call it Slingstream 2.0, basically its an encrypted stream that encapsulate WMV9 or H.264 video and AAC, PCM, or WMA audio based on the connecting client.  It also limits the video output resolution based on the client as well as uses intra-coded frame compression and variable bit rates in order to reduce bandwidth.  Over the network it uses one of three methods of connection: TCP, UDP, TCP via web proxy.  Here's their lastest white paper if you're interested in more information: (www.slingmedia.com/get/io_1255477160645.html)

           

          As far as it goes, every streaming client will buffer.  This is to allow for smooth video despite a reasonable amount of drop packets.  For the Slingbox its no different; however, I haven't noticed a delay higher than a few seconds.  You can rest the lag by hitting the virtual remote on any client but it  will resume to buffer.  The Slingplayer desktop will allow you to toggle "Control Mode".  Which shows a quicker remote control response; however, while its in this mode the picture will be choppy.

          • Re: Live TV Delay
            BrandonC Novice

            The iPhone should have the standard  5 second delay or "preload" So I would expect about that.

            • Re: Live TV Delay
              tckitty

              Could you share your VLC configuration?  I tried UDP with the private IP and  port but is not working for me.  Any help is appreciated. I have the Pro HD.