An attempt to cover the basics of video production. Corrections and improvements welcome. Preamble
To the average Windows user, QuickTime is just another annoying icon on their desktop, one that probably appeared after they installed iTunes. Those who click it will be presented with promotions from Apple that they probably don't want. I don't want them either.
But to movie people, from Hollywood down, QuickTime is the industry standard for video.
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Master Edits
Video editors mostly work on raw DV footage with FinalCut, Avid, or (less often) Premiere. Whatever they use, a master edit will usually be prepared and saved as a high quality QuickTime compatible movie, in MOV or AVI, so that it can be previewed by interested parties.
Both MOV and AVI are container formats that can include separate audio and video tracks, each of which can be compressed with many different codecs (short for COmpressor-DECompressor) at various quality settings. The master will be saved using a "lossless" video codec - these are not entirely lossless but result in a very big file, usually measured in gigabytes. Audio tracks would be uncompressed.
The master edit might be DVD size (720 pixels wide) but larger HD sizes are fast becoming the norm. Whatever size you start at, web-ready exports may be produced at a variety of smaller sizes, often at lower frame rates, and in a variety of formats.
For non-professionals, there are many entry-level software packages that can be used to edit video. Your mileage may vary, but if you keep it simple the results should be acceptable for the web.
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Exporting and Transcoding
From the master, many versions can be prepared: MPEG-2 for DVD, MPEG-1 for VCD, Mp4 and 3GP for handhelds, and most likely FLV or Mp4 for web delivery. As long as you have the compression codecs you can export to other formats such as OGG, Real or WMV if you wish. Whatever you choose, your viewers will need the correct decompression codec and a suitable player to actually watch the video.
Professional editors will export directly from FinalCut, Avid or Premiere. There are countless consumer-level converters available to transcode between compressed video formats, but this is not recommended and you will always be better off working from the source.
Even that annoying QuickTime icon on the desktop can be used for transcoding - if you pay the small fee to upgrade it to QuickTime Pro, which will export in any format you have the codec for. QuickTime Pro also has some built-in editing capabilities, though these are only rudimentary (accurate to about one second rather than one frame).
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Size Matters
In dial-up days, web video was mostly 160x120 pixels, sometimes even smaller. With the broadband revolution we have progressed through 240x180 to 320x240 as a common size, and the standard is continually being raised.
A recent change is the move to widescreen formats with a 16:9 aspect ratio. Hollywood movies are actually shot with an even wider ratio, and much of the image is lost when presented on traditional 4:3 television screens. The new trend is for wider screen resolutions, and this is particularly noticeable on the latest laptops.
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Data Rates
For web delivery, data rate is a crucially important setting - make it too high and you will lose viewers with older, slower processors. Where you draw the line is up to you, but over time you will want to draw it higher up the scale as technology improves and old hardware dies out.
I usually limit the video data rate to 384 kbytes/sec, which plays smoothly on my vintage laptop, but some high-end sites are now using rates that won't play back properly on that venerable machine, even after downloading. They are telling me "buy a new computer" rather than "watch my movie".
Web video is often about compromise. Know your audience.
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Mp4 Variations
Like AVI and MOV, Mp4 is a container format that can use various codecs. The video industry favours H264/AAC, which is supported on a growing number of DVD players and mobile devices, and can be played on computers with RealPlayer, QuickTime and others. Microsoft, however, chose not to implement AAC audio in Windows Media Player.
DivX, 3ivx and Xvid are essentially Mp4 formats, but with slight differences that make them unsuitable for the web (there is a DivX web player but don't expect anyone to have it installed).
Another variation is 3gp, used for video on older phones (which can include non-Mp4 content such as H263 video and AMR audio), and M4v is an extension used by Apple that can usually be changed to Mp4 with no ill-effect - this is what YouTube currently offers to iPhone users.
So Mp4 is versatile (or confusing, if you prefer), and using ISMA profiles is recommended for maximum compatibility across devices.
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How The Web Was Won
You don't see so many QuickTime movies on the web these days, but some will remember it as the example given in old HTML textbooks, and it is what I first used back in the 1990s. Poor cross-platform performance seems to have been its downfall - Apple controls the hardware in its computers, but cheaper PCs often had insufficient graphics capabilities, and many people found QuickTime unusable on Windows.
Windows Media has also had a very poor history on the web, due to cross-platform and playback issues. To many webmasters it has always been the worst possible option.
So most of the web turned to RealPlayer and eventually to Flash, which offers better interactivity and scripting options than QuickTime, and which is much less effort to download and install. The success of YouTube has been a major factor in the adoption of Flash video, which was even used on Microsoft's MSN Video website last time I looked.
There are still some websites that use QuickTime though - video professionals want higher quality than Flash generally provides, and some are confident enough to insist that visitors meet their requirements. Amongst these the trend is for H264/AAC in widescreen formats.
Flash 9 player now supports H264/AAC, allowing the use of Mp4 compliant video in Flash - it is possible to load existing Mp4, 3gp and (some) MOV files at runtime, but don't expect smooth performance on old or lower-end hardware.
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The Unholy Grail
Web video has been around a long time, starting with the postage stamp sizes and low quality that worked in another century. But it has always been heading in one direction: full-screen, high-quality, live broadcasting, user input - in short, interactive web television.
And it's not just about computers - phones, games consoles and iPods all play video, and all can connect to the internet. Reading text on small devices is no fun, but the power of TV commercials is well-known, and while I will personally hate the idea, I expect major changes in online advertising.
We are not quite there yet, but we may be sooner than you think.
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Postamble
Fashions can change fast on the web. Video formats come and go.
Real Media once dominated, even over Microsoft and Apple products, until YouTube brought Adobe's Flash video to the masses. The WikiMedia Foundation promotes (for now) the open-source Ogg Theora format, but whether it will ever become popular is debatable. And some new product could come along and capture the public's imagination (or lack of it) very quickly.
As things stand, most websites will want to use Flash, but this currently has two disadvantages: it does not (yet) work on mobile devices, and if you want to use real-time streaming then Flash Media Server requires a substantial outlay (though it is possible to rent rather than buy).
For those who cannot afford it, a free cross-platform open-source alternative is Darwin, a version of QuickTime Streaming Server that can broadcast Mp4 streams to multiple devices, but it also has two disadvantages: the streams will not work with the Flash 9 player (apparently an Adobe-imposed restriction) so viewers must have QuickTime installed, and to the average Windows user, QuickTime is just another annoying icon on their desktop...
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