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New
Kinds of Video
Even
if we stick solely to streaming video on the World Wide Web, there
are multiple variables to be considered, and in some ways, we're
moving backwards. Unlike video compression on finished-program-quality
non-linear editing systems which long ago passed the "good enough"
stage, streaming video on the Web requires substantial quality compromises.
After all, to reach a large audience on the Web, video clips have
to be accessible to dial-up modem users who are connecting at 28.8
Kbps or worse. That's certainly a far cry from the multiple megabytes
per second that non-linear online systems use.
 For example, producers like
Alex Kilgo who produces video and a web site called DRTV World for
the direct response television industry makes distinctions between
"high motion and low motion video" that just don't come up when
using full motion video. Unfortunately, it's the opposite of high
production values. As anyone who has worked with compressed video
(for example, for CD-ROM's) knows, camera motion like pans, zooms
and dollies which are normally used to enhance the visual interest
of a production cause low-bandwidth codec's (compression/decompression
software) to "choke," thus causing frame rates to plummet.
"Highly
produced video is not very
well-suited for the Internet."
CPB's
Coltman says, "Highly produced video is not very well-suited for
the Internet. Live video, timely events that are mostly talking
heads but which have very little production value make sense." I've
observed that one of the best compromises is news-style cutting
where whole scenes change but where there is little camera movement
within a scene.
A
more concrete example is the Warner
Brothers movie site which previously offered only downloads
and, for the moment, primarily uses the QuickTime plug-in player
with Iterated's ClearVideo codec. VP of Advertising & Promotion
for Warner Brothers Online, Don Buckley told me that online video
is "more appropriate for talking head, talent interviews" rather
than more complex trailers and music videos.
"No
one on the Internet will want to watch
a 30-minute newcast, so the newscasts
will be structured in four to five minute
on-demand segments."
 The
other fundamental to remember is that online video works best when
it leverages the interactivity of the web. I'll write more in future
columns about new forms of interactive video, but Scott Bourne describes
it well when he talks about his First-TV,
Internet-only "TV network," "The bottom line is that viewers can
watch what they want when they want it, so content has to be designed
with that in mind. For example, no one on the Internet will want
to watch a 30-minute newscast, so the newscasts will be structured
in four to five minute on-demand segments." Actually, in some cases,
four to five minutes may be too long; but then again the user has
complete control because the computer mouse is a far more sophisticated
control device than any TV-zapping remote control.
New Compression Paradigms
From
the technical point of view, the Video Web also offers an increasing
array of options. At the time of this writing, VDOnet's
VDOLive video player appears to be the online video streaming leader
in terms of sophisticated server software (including the only live
event broadcast server that supports dial-up modems) and their collection
of high-profile content providers (for example, FoxNews, a major
studio movie trailer test in partnership with search site InfoSeek,
and SportsLine. The VivoActive
video player from Vivo
Software,Inc. is also attracting an increasingly large following
and the ClearVideo codec from Iterated
Systems which uses the QuickTime plug-in as its player (although
it is technically not yet a streaming codec) illustrates the possibility
that Apple's
QuickTime media architecture may emerge as an important cross-platform
standard in the online market.
While
there are many other codec's currently and planned for the online
video market, I will use the three mentioned above as my illustrations
for this article and cover some of the others in future columns.
These others include Vosaic (said to have great technology, but
still under development), Xing (requires an ISDN connection or better),
VXtreme, Network MPEG, Microsoft's ActiveMovie (so far only downloads
a few seconds, then plays a few seconds, etc.) and Narrative Communications
(just announced). In addition, at press time, Progressive Networks,
the Internet audio leader with RealAudio, was rumored to be almost
ready to announce "RealVideo," but to date, this much anticipated
product is still vaporware.
One
new distinction, or selection criteria, that differentiates these
various codec's is the fact that some are server-enhanced while
others are server-independent. This is an interesting variable that
offers advantages and disadvantages on both sides.
VDOnet's
VDOLive video player is a good example of a server-enhanced codec.
Like the RealAudio servers, VDOnet sells server software that manages
the steaming process. This limits the number of streams available
at a given time which in effect enhances the video quality by making
sure that the server does not get overloaded and that each user
gets a dedicated stream. Furthermore, VDOLive's server is intelligent
enough to scale the video stream according to the bandwidth of the
user's connection and to the traffic on the Internet at a given
time. It also dishes out the video intelligently, for example, by
giving audio top priority so that the stream is as continuous as
possible. Vivo, on the other hand, has a distinct tendency to pause
unexpectedly. Unfortunately, because of the size of the market and
because VDOLive is avi-based, VDOLive focuses on Windows implementation.
There is a Mac VDOLive player that requires a PowerPC, but it is
significantly inferior to the Windows player.
"The
Quick Time plug-in is limited to
a feature called Fast-Start which
technically is not streaming, but a
"progressive download."
So
far, the QuickTime plug-in is limited to a feature called Fast-Start
which technically is not streaming, but a "progressive download"
that approaches streaming if the clip is sufficiently compressed.
Fast-Start is smart enough (when it works right) to measure the
rate at which you are downloading and then loads enough of the clip
to ensure play-through, and then start playing while the remainder
of the clip is downloaded. The familiar QuickTime play bar fills
with black to show you how much of the clip is downloaded. This
also gives you functionality like the ability to save a clip and
rewind a clip that the others do not provide. Apple is making efforts
to make QuickTime a cross-platform player and expects the Windows
player to equal the Mac player by the first quarter of '97. It should
also be noted that unlike proprietary codec's like VDOLive and Vivo,
QuickTime is a media architecture that can support multiple codec's.
 Getting
sufficient compression is where Iterated's ClearVideo codec comes
in. DRTV World's Kilgo raves about the quality of the images that
he can compress to very small bit rates using ClearVideo, but acknowledges
that due to Iterate's fractal approach, the compression times necessary
to produce the clips are very high. Despite the fact that he is
forced to use designated Mac workstations for compression, he says
that the time is "worth it."
What
also distinguishes Vivo and the current implementation of the QuickTime
plug-in from VDOLive is that neither of these codec's require special
server software. VivoActive and any codec that uses the QuickTime
player can send the video directly from any web server (or web page)
just like any other type of file. Besides being far simpler and
less expensive to implement, this approach is not limited by corporate
firewall problems that server-based systems like VDOLive are struggling
to overcome.
On
the downside, server independent solutions like VivoActive and QuickTime
are likely to suffer more from Internet congestion because they
cannot adapt to changing connection conditions. Given the demands
that video (even highly compressed video) can place on an Internet
server, it's fair to say that programs that will attract large audiences
or sites that plan to deliver any significant amount of simultaneous
video streams over the Internet will need some kind of server and/or
bandwidth management software. However, for controlled approaches,
like NBC Desktop Video's subscription-based service, this is not
an issue. NBC Desktop Video will just acquire more bandwidth whenever
they get more subscribers.
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