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Quicktime 3.0 -
The Multi-Platform Non-Streaming Streamer

by Jon Leland
Originally published in Videography Magazine, February 1998
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Apple Interim CEO and founder Steve Jobs used the occasion of his keynote at January's MacWorld Expo to place the upcoming release of QuickTime 3.0 into competition with RealNetworks' RealVideo (not to mention Microsoft NetShow). While he did make some significant announcements; unfortunately, he also blurred the role of QuickTime on the Internet by clouding the meaning of "streaming," the Internet's most popular real time video technology.

What was encouraging for videographers was that in addition to the announcement of Apple's first significant profit in two years, Jobs reassured Mac-based producers that QuickTime (unlike Open Doc and others) will continue to be a "pillar" technology at Apple. He said that Apple is pumping resources into the technology (Jobs reported that "100 engineers" were working on the upcoming release of QuickTime 3.0) in an attempt to further it as a multi-platform standard.

In making his QuickTime announcements, Chairman Jobs indirectly referred to Microsoft's Active Movie format (without mentioning it by name) by claiming that "Microsoft does not compete in deed" with QuickTime. Video professionals would certainly understand this reference to the fact that, in recent years, Windows-based video systems have been playing catch up with Mac/QuickTime-based video systems.

However, Jobs chose to focus on RealVideo for other reasons. First, he knew that RealVideo does not compete with QuickTime in markets like professional video and CD-ROM. And secondly, Jobs thought by announcing that QuickTime's new codecs deliver a "streaming" capability that he would gain some additional positive spin for the launch of QuickTime 3 (which is due to ship "in February.") The truth is that what Jobs called "streaming" is actually QuickTime's Fast Start capability (which I wrote about in Videography over a year ago) which is now enhanced by new codecs. The result is better described as a "real time download."

The term "streaming" refers to the technology which broke the Video Web's "download barrier" by providing real time video on-demand. Streaming, as the term is technically used, refers to a client-server technology that can also enable live video webcasts and multicasting (see "The Video Web" column "Untwisting the Trends," Videography, November, 1997.) Other Internet video like Vivo, animation software like Macromedia's Flash and Shockwave, or even the HTTP version of RealVideo does a different version of what QuickTime 3 does, which has also occasionally been called "serverless streaming."

The real heart (or at least the most practical part) of Jobs' QuickTime announcement was that Apple had licensed new codecs, in particular a video codec from Sorenson Vision, a music codec from QDesign Music Technology and a voice codec from QUALCOMM. (More on this below.)

The way QuickTime serves video in virtual real time is that if a movie is compressed to playback at a data rate that is slower than your Internet connection's bandwidth, you can play that video clip while it's being downloaded. Fast Start enhances this experience (when it's enabled within the HTML code) by automatically starting a video clip when enough of it has been downloaded to ensure uninterrupted play. With QuickTime, you can also start and play the first part of a clip (while the remainder is still being downloaded.) This may be used, for example, to preview the beginning of a clip to see if you even want to view the rest. I find this feature quite useful.

People are frequently confused about how to compare Internet data rates with hard drive data rates, so let's do a quick review. Modems deliver bits. Hard drives store bytes. And, there are "8 bits to the byte." Thus, for example, if you take last year's standard modem with a throughput of (28,800 bytes or) 28.8 Kbps/second, and divide by 8, you get 3.6 Kbytes/sec. Of course, in the real world, one rarely ever experiences their full potential modem bandwidth, so 3Kbytes/second is a reasonable ballpark for a 28.8 modem's Internet connection.

The video clip from Apple's QuickTime web site shown in this article's sample image uses 425 bytes/second for "video 2" at 3 frames/second and 992 bytes/second for its high quality audio track (both at the choice of the "compressionist") for a combined data rate of about 1.4Kbytes/second. With Fast Start enabled and QuickTime 3.0 installed, a dial-up user with a 28.8 modem should be able to hear and watch this clip without any waiting whatsoever.

To give you some data rate perspective, the base rate for an old-fashioned double-speed CD-ROM drive was about 100Kbytes/second, and professional non-linear editing systems are normally dealing with data rates from 3 to 10MB/second for full screen, full motion playback. That's roughly from 1,000 to 3,000 times more data per second than a 28.8 modem. Or, to provide another perspective, Senior QuickTime Architect Peter Hoddie at a press briefing said QuickTime 3 is delivering low bandwidth clips with the same frame size (160 x 120 pixels), but much higher quality with 1/90th the data size of what was delivered by the original version of QuickTime 1.0 when that breakthrough technology was delivered exactly six years ago. Thankfully, this trend toward better and better compression quality and performance will undoubtedly continue.

Another interesting trade off with QuickTime's approach (rather than with streaming) is that the producer can make a quality decision about how he or she wants a particular clip to look (i.e. how much video and/or audio quality can be compromised for online presentation). Then, depending on that decision, users with a higher bandwidth connection (for example, users with 56K modems) may get a virtually real time experience while others will have to wait for the clip to download. However, in all cases, using QuickTime 3's approach, you as producer know that every viewer will get the same quality. Streaming delivery, on the other hand, is committed to a real time experience no matter what, so quality is frequently compromised in order to achieve this more immediate result.

Whether you want to call QuickTime's Fast Start, "real time downloads" or "streaming," it's clearly encouraging for Apple that despite the fact that QuickTime has not previously had codecs that made it viable at dial-up bandwidths, QuickTime is still a dominant media type on the Web. According to Apple and other sources, reports from last year quantify The Video Web universe as about 50% QuickTime and 20% RealVideo with the rest at very minor fractions (although I suspect that Microsoft NetShow is just about to grow to reach competitive numbers.) Apple claimed that QuickTime is currently being used on 81,000 web sites.

What's especially impressive about this is that QuickTime achieved this broad distribution not as a Web plug-in, but as a system extension. What needs to be remembered (both for better and worse, and despite Chairman Jobs' attempt to cloud this issue) is that beside "streaming" and "real time playback," there is another fundamental difference between QuickTime and RealVideo. QuickTime is a system extension and RealVideo is a web extension.

In fact, one of the most important accomplishments of QuickTime 3 is that it promises to create a consistent standard between Mac and Windows versions, and this is being done with the intense challenges of making system-level software compatible. Of course, this is not a minor undertaking and must certainly account for some of the delays in bringing QuickTime 3 to market. While RealMedia also likes to talk about itself as a multimedia architecture (and it deserves the term for the mix of media that it is capable of converging), it limits itself only to the emerging world of online multimedia, whereas QuickTime supports everything from professional video applications to CD-ROM, DVD and the Web.

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