Is High Definition video conferencing worth it?

Is High Definition video conferencing worth it?

Summary: Is High Definition video conferencing worth it? Find out what we learned at Interop 2006.

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TOPICS: Telcos
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When I blogged about the startup LifeSize Communications last year, the product hadn't actually shipped yet and all the bugs hadn't been worked.  In December 2005, the first high definition video conferencing systems from LifeSize shipped and we were treated to multiple real life demonstrations and were communicating to people on the other side of the country at this years Interop convention.

The LifeSize solution operates at a resolution of 720p (1280 x 720) resolution whereas standard definition video conferencing operates at 480p (640 x 480).  For the demonstration, a 1 mbps stream was sent over the public Internet to Austin Texas from Las Vegas Nevada.  Of that 1 mbps link, 900 kbps were allocated to video and 100 kbps were allocated to 100 kbps wideband audio.


High Definition versus Standard Definition video conferencing

In the picture above showing and HD and SD picture side by side, I thought it was odd that there didn't seem to be too much difference between the images at a distance besides the fact that the HD image fills the entire wide screen.  This is surprising because a 720p image has 3 times the pixels of a 480p stream yet the two images looked similar in smoothness from a distance.  When I moved to normal viewing distances, I could definitely see a lot more detail in the HD image yet the difference wasn't as obvious as you would think it should be since the SD image wasn't any more pixilated than the HD image.  Then it struck me that the reason there wasn't any more pixilation in the SD image was because nearly all modern large screen displays use anti-aliasing technology that removes the pixilation of lower resolution video sources by up sampling them to maximum resolution.

This brings up an interesting technological debate since both video streams use the same data rates of 1 million bits per second.  This means that the HD stream obviously has to be compressed 3 times as much as the SD stream to fit in to the same 1 mbps pipe.  The only difference is that the SD stream starts out at a lower quality level but doesn't get chopped down as much with compression as the HD stream.  Since most modern displays up sample SD video sources to HD resolutions anyways, it would seem to be a wash between the SD and HD solution.  But this clearly isn't the case since the HD image is noticeably superior in detail but this sounds like we're getting a free lunch so what could explain this?  What's happening is that lower resolution of the SD image indiscriminately throws away finer detail by starting with 3 times fewer pixels whereas the H.264 video compression algorithm has the luxury of picking and choosing what it wants to discard if it had a higher resolution stream to work with.  The end result is that while HD video conferencing at 1 mbps can't truly deliver three times the quality of an SD video conferencing at 1 mbps since only 3 mbps HD stream can, it can approximate three times the quality and come close to it under most circumstances when where is little movement or change in the video.

The bottom line is that HD video conferencing is fundamentally superior to SD video conferencing even when you give both of them the same bit rate and you display both on an up sampling display.  The really big question is if you should buy it.  As it turns out, the $12,000 price tag (list) is the same that you would pay for a high-end standard video conferencing system anyways from any of the more established players in the industry.  With all the extra quality in sound and video, it makes video conferencing a lot closer to a face to face meeting so it may end up saving you a lot of travel expenses.  With a clear technological lead, LifeSize seems to be on the way up in the world of video conferencing.

Topic: Telcos

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24 comments
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  • Mixed Review?

    Now that the company that I work for has taken the video conferencing plunge and enjoyed a bit of it, are the advantages of HD really there. Being in as remote location as I am, 1mbps seems pretty high. Currently our equipment is running over ISDN. I couldn't imagine what that image would look like if it were compressed any further.

    Bravo for Lifesize though. If they can offer a product that is superior to SD and yet keep around the same sticker price, they should be able to sell themselves very easily.
    nucrash
    • It's for the dedicated conference rooms

      It's not for you to take home on a broadband connection (though some people are lucky enough to have 1 mbps up stream). Even so, not many companies will send you home with a $10K box.

      So to answer your question, yes it is well worth it in my opion for the right location.
      georgeou
      • LifeSize Looks Great at any Bandwidth

        Hi, George, the video does indeed look great at 1 megabit/sec. But the other thing is that the LifeSize video also holds up and looks better than any competitor lower bandwidths as well.
        Rick Popko
        (LifeSize)
        RickPopko
        • Why would that be the case?

          It's the same H.264 codec is it not? I wouldn't expect HD video to hold up too well at 384 kbps unless there was no video noise (bright lights) and almost no movement in the picture.
          georgeou
  • So

    if you compressed the SD channel at the same ratio as the HD channel, then you would only need a 333Kbps pipe instead of 1Mbps pipe. THAT might work over an ISDN connection . . .

    So what you are saying is that IF you have the bandwidth, HD is the way to go.
    Roger Ramjet
    • That's already being done, but it doesn't look as nice

      If you use Polycom software at that bit rate, it looks ok but not nearly as nice as 1 mbps SD video which in turn isn't close to 1 mbps HD video. That's not to say that 333 kbps SD conferencing isn't useful because it is on a good broadband connection (ISDN operates at 128 or 1544 mbps), but just don't compare it to the 1 mbps streams.
      georgeou
      • ISDN at 1544 mbps?

        Where do I sign up for that? I would settle for the 128 mbps.

        Sorry, just have to harrass you about a typo.
        nucrash
        • BRI versus PRI

          A PRI is 24 B channels and costs as much as a T1 connection. There there's metered usage charge that can easily rack up $30K a month if you forget to turn it off. So no, it's not a good idea but it does exist.
          georgeou
          • I thought that was a typo

            Apparently decimals were never your friend in math either.

            Actually, I was studying up for my Network+ Exam and thought the idea of my company buying an ISDN connection was still pretty dated. However, since Corporate chose that route, we now live with what I think is a 128K connection. I will double check on that though. Polycom has kindof miffed us with their equipment.
            nucrash
          • Ah sorry, didn't catch that typo of M versus K

            I had mean 1536 kbps, not mbps.
            georgeou
      • wow!

        That's not to say that 333 kbps SD conferencing isn't useful because it is on a good broadband connection (ISDN operates at 128 or 1544 mbps), but just don't compare it to the 1 mbps streams.

        both those numbers are way faster than 1mbs so how could you compare it to a 1mbs stream
        richvball44
  • Compression choices

    The other variable that has a lot to do with what quality you get at the other end of a video call is the codec = compression. As I understand it, this is purely a software issue.

    A lot of interesting work is being done to improve compression ratios, which includes discarding information that is not needed before you compress that. For instance, sightspeed.com focusses on providing more information about changes in facial expression than other aspects of the picture. Most interesting is vsee.com - a project being hatched out of Stanford (under the same professors who surpervised the doctoral project that ultimately became Google, no less) - the criteria Vsee uses to decide what data to keep and what to discard is too abstruse for me - but I like what I see. And after all, that's what it's all about, isn't it?
    logus
    • No, same h.264 codec

      Both solutions are using the same H.264 codec
      georgeou
      • Go to Apple will ya!

        I haven't seen movies on the computer screen with as high quality
        as these at http://www.apple.com/trailers/

        The 1080p versions are a bit tough to playback but are also HUGE,
        1920x816.
        Mikael_z
        • Windows media does same thing, but neither good for conferencing

          1080p is 1920 x 1080 resolution, and Windows Media handles it just fine. The problem is that neither Quicktime nor Windows Media is good for real-time non-buffered Video Conferencing unless you're willing to take a 10 second delay.

          As for buffered streaming playback, BMW films use to have a bunch of videos back in 2000 for Windows Media, Quicktime, and Real Video at 300 kbps and the Windows Media version did the best at 300 kbps.
          georgeou
  • Upconversion

    They should have used a standard definition television next to a high definition television for a better example. Both examples were showing the same number of horizontal scan lines (720).

    But I do agree with your conclusion. HD does have many benefits. Of course these benefits are in details, and in a business environment I might be distracted counting the pores on the person's face instead of engaging in the conversation.

    I guess I could have just said, the source material doesn't really benefit from 720p as much as Terminator 2 would.
    glocks out
    • Then it would have been called a bogus comparison

      "They should have used a standard definition television next to a high definition television for a better example. Both examples were showing the same number of horizontal scan lines (720)."

      If Lifesize had used a lesser TV to display the output of the 480i Polycom system, the differences would have been blamed on the TV and not on Lifesize's superior resolution. Realistically, people will use newer TVs that up convert anyways if they're buying a new system. I think this was a fair comparison to have upconversion for both solutions since this would be a real world situation.
      georgeou
      • no....

        its just a damned conference call. who needs to waste corprate bandwidth so you tell if you can see the thread count on some suits???
        richvball44
        • Depends on the purpose of the call

          If you're trying to make a critical sale or critical business decision, it matters. If it saves you a face to face trip, it matters.
          georgeou
          • wrong

            ive been around people in public relations that have over 50 years combined experience. experience shows that face to face works. not conference calls
            richvball44