Following up on my last post, I got a chance to see the demo of TiVo Desktop 2.6 in TiVo’s suite today and I got a few photos of the desktop UI changes. I picked up some of the details on how this will work, which I found very interesting, and I think some of the geeks reading this will too, especially for the implications. Unfortunately, I didn’t get a chance to ask all the questions I had since I hit that station shortly before they closed the suite down for the day, so I’ll be going back with some more questions.

I want to point out that I updated the last post to remove the details relating to the Mac software. Specifics of the Mac solution had been reported which were not authorized to be published. But there is a Mac solution coming, the details are just not releasable at the moment. No, I’m not telling, don’t bug me about it. Just remain calm.

With the new TiVo Desktop, you link it with your TiVo account online. That’s not something you do today:

Why? I’ll get into that below.

You can subscribe to a list of videocasts from an HME interface on the TiVo, and it is quite an extensive list. I didn’t get good shots of that interface, I’ll try tomorrow, but ZatzNotFunny, Engadget, and EngadgetHD all have coverage with some photos if you can’t wait.

If the videocast you want isn’t in the list, then you can go to TiVo Desktop and add it there.

The settings are fairly simple. You point the desktop at the folder where the videocast is saved on your PC. Note that the TiVo Desktop software doesn’t include the RSS feed reader to download itself, which could be a nice feature for 2.7. Instead, you use your favorite podcast software, such as iTunes, and simply point the desktop to the folder your software downloads to. You then select if you want the video automatically transferred to a TiVo or not. If so, then you set how many episodes you want transferred to the TiVo at a time and which TiVo(s) to transfer to. Finally, you can select whether or not to include subfolders.

All video is transcoded to MPEG-2 before transfer to the TiVo. The Series2/2DT units only support MPEG-2, and while the Series3 and TiVo HD have the hardware for advanced codecs, the software support isn’t there yet. In the future, once those codecs are enabled, such as H.264, it is likely that the desktop will transfer video already in those codecs ‘as is’. If the source video is high definition, and it is being transferred to a Series3 or TiVo HD, then it is kept HD through the transcode. If it is transferred to a Series2 then it is encoded as SD to enable playback. And yes, this does mean that your PC needs to be one for this to work. You don’t necessarily need to leave it on all the time, but you’ll need to have it on long enough for the PC to grab your downloads, transcode them, and transfer them to the TiVo(s).

OK, so why is the desktop linked to your account online? Because the TiVo back-end plays a role in the new system. Today each TiVo polls TiVo’s severs roughly every 15 minutes to check for new scheduled recordings, TiVoCast downloads, Unbox downloads, etc. That’s highly inefficient – nearly all of those polling calls are for nothing. There is nothing waiting to be done. And it introduces a lag when you want to start a download – up to 15 minutes. And it doesn’t scale well as TiVo’s user base keeps growing.

So what’s changed? The polling system is gone. TiVo is using XMPP now instead. What is XMPP? The Extensible Messaging and Presence Protocol – better known as the instant messaging protocol that powers Jabber, Google Talk, and other IM systems. Yep, TiVo is basically using instant messaging for real-time communication. Now when the TiVo server has a new recording to schedule, it will IM the TiVo to tell it. Or if there is a download to pull, it will IM the TiVo to tell it to do so. This is a much more efficient system and it eliminates latency. It is really a clever idea.

Now, the way this works with web video is that when the desktop finds a new video and has it ready to transfer to the TiVo, it sends an IM to TiVo’s servers. TiVo’s servers then send an IM to the TiVo to tell it to grab the video. Which brings up another new twist.

This does not use the TiVoToGo/TiVoToComeBack protocol, it uses TiVoCast. Yep. your PC becomes a TiVoCast server, and the TiVo grabs the video from the PC just like it does today from the TiVoCast servers online.

While I think the 2.6 web video features are great, I think the work done to implement the infrastructure could be the bigger story. Replacing polling with XMPP opens the door to all kinds of improvements. Instant starts to downloads of TiVoCast or Unbox video, or any other video source, such as Music Choice music videos. If there is a schedule change that impacts your TiVo, TiVo could tell your box to grab it right now instead of waiting a day. It even opens the door to possibly handling last minute changes such as sporting events running long, Presidential addresses, and other events that bump the schedule at the last minute. TiVo’s servers could instantly IM units to warn them of the changes. Though there would have to be a lot of additional work to provide a full service.

And being able to trigger a TiVoCast download from basically any server on the net would really open the door to 3rd party content providers to setup their own content servers – if TiVo opens this up. Right now it doesn’t sound like this functionality will be open to 3rd parties, but the foundation is there. I’d love to see TiVo update the HME SDK with the ability to trigger TiVoCast, that would be a major jump.

I have some more, but I want to get some clarifications, and make sure that it is OK to share everything before I do. But I’m excited by some of the things I heard today about the work being done. I hope to have more to share tomorrow. But right now I need some sleep.