Choosing a Data Rate
I'll start by addressing the most significant concern most wedding and event videographers have about streaming. You spend upwards of 40 hours shooting and editing the perfect video, the last thing you want to do is compress it in a way that makes it look worse. And if you know much about compression, particularly streaming compression, you know that high-motion videos with lots of changes don't look particularly good when streamed over the internet. Of course, if you know much about wedding videos, particularly demo reels, you know that high-motion videos with lots of changes are often most appealing to potential buyers. Is this a problem?
Thankfully, no. As long as you encode using reasonable parameters, which I detail below, and keep your videos relatively short—say, five minutes or so—you should be able to encode at a data rate high enough to preserve quality irrespective of the motion in the video. This applies specifically to demo videos you post on your site for marketing purposes. You can go even longer for client videos so long as they understand that they may have to wait a while to actually see the videos.
There are two reasons for this. First, most clients that can afford your fees probably have broadband, which is reflected in the data rates used by major consumer sites on the web, like ESPN, Digital Life TV (DL.TV), or CBS. For example, ESPN posts their videos at 400-600 kilobits per second (Kbps), as does DL.TV. These numbers, unheard of only a few months ago, indicate that most relevant viewers can easily play these videos without delay. Second, as I'll detail in a later section, you don't have to stream your video--you can distribute it via progressive download.
Let me explain a couple of concepts. Data rate is the size of the video file per second of data, usually expressed in kilobits or megabits per second. When I say that ESPN distributes their video at 600Kbps, this means that each one-second chunk of audio and video comprises about 600 kilobits of data.
The concept of streaming means that you click the button on a website, the video starts playing immediately, and it continues to play more or less smoothly to the end. When you stream video, the data rate must be somewhat smaller than the bandwidth capacity of the remote viewer; otherwise, the video will frequently stop playing. For example, if you try to watch ESPN.com on your broadband connection, the videos will probably stream smoothly from start to finish. If you connect via a 28.8Kbps modem (remember those?), the video will stop and start like pre-strike MLB salary-cap negotiations.
Progressive download is a fancy name for a process that stores a video file to disk in a temp folder during playback. That way, though the initial playback may not be that smooth, if you wait long enough, the video will play smoothly because you've got a local copy stored to your disk. Apple reportedly pioneered this technique for George Lucas, who famously said "there are 24 frames per second in this movie and none of them are optional." I still remember my oldest daughter waiting hours for a high-resolution preview of the Disney movie Dinosaur to download over our modem connection. When it finally finished, it looked great.
Like George Lucas, when you distribute your videos via progressive download, you can encode at a data rate high enough to ensure their compressed quality. If you're concerned that your prospects won't wait even a few minutes for high-quality video, you can always post a low-resolution version for quick viewing and a high-resolution version for optimal quality. Or, as we'll discuss, you can even post videos using multiple compression technologies, some targeted at fast viewing, some targeted at perfect quality. The overarching point is that concerns about video quality should not keep our video files off the web.
One note about progressive download: If you're concerned about copyright violation (i.e., other videographers stealing your work from your website), the hard-drive caching involved will make you susceptible to that sort of IP theft. Streaming is a much better deterrent because the video you deliver is never resident on the end user's hard drive, although a number of screen recording tools make it fairly easy to copy video streams with little quality degradation. If you're delivering a final product to clients and need to make it available to them for download, keep that video in a password-protected section of your site. And always watermark your work so your copyright ownership is clear and easily identified.
Choosing a Codec
I've worked with compression technologies, or codecs, since the days of CD-ROMs, most recently authoring two research reports for StreamingMedia.com that detailed the respective quality of the four major codecs: Adobe Flash Video, Apple QuickTime, Microsoft Windows Media Technologies, and RealNetworks RealVideo. The bottom line is that once you boost the data rates beyond 500-600Kbps or so, the differences in quality are negligible. At the data rates I suggest that you use, any codec will do the job, so output quality is not a relevant differentiator.
Before getting into the strengths and weaknesses of the individual codecs (and there are other factors, besides quality, that should impact your decision), let's discuss our goals. First, of course, is to provide a high-quality video for our prospective or current clients to view. In addition, it's helpful to provide a high-quality file that these same viewers can share with their family and friends. In many cases, this means providing a downloadable file that's compatible with a video iPod or other portable media player.
One other goal that's at least worth considering is to provide a stream in a format that the viewer will want to watch. This is best typified by the aforementioned website DL.TV, a weekly web-only TV show produced by Ziff Davis. DL.TV streams the show live in Windows Media format during shooting. Then, it makes the show available in five different video configurations, as well as MP3 audio, as shown in Figure 1, left.
According to Patrick Norton, DL.TV's co-host and executive producer, 40% of the viewers download for the video iPod, 20% view via Flash, 15% watch via Windows Media and QuickTime H.264, and the remaining 10% watch DivX-encoded clips. You can draw several conclusions from this data. First, DL.TV's technical viewers have clear codec preferences, and presumably enjoy the show better when watching with their favorite codec. When it comes to codec support, more is definitely better. Second, the timeshifting ability enabled by the video iPod is a huge draw for many viewers. Third, RealVideo isn't included. When I asked Norton why, he told me that Real's player has a reputation for intrusiveness and perhaps as a result, no viewer had ever asked the show for video in that format. For me, that's reason enough to take RealVideo out of consideration for your demo videos. I'll also throw DivX out of the running because its audience is largely comprised of highly technical users that are generally not in the mainstream.
This leaves us with three choices: Flash, QuickTime, and Windows Media. Let's discuss Flash first.
Working with Flash
Briefly, Flash Video is the codec of choice for many of the old-guard streamers, like ESPN, CNN, MTV, ABC, and The Golf Channel, and it also enjoys popularity among web-video newcomers like BusinessWeek, Sports Illustrated, Forbes, The Wall Street Journal, and CNET. There are many reasons for this—some of them highly relevant to wedding and event videographers—and some actual negatives.
For example, ESPN chose Flash primarily because they could easily design a custom player that made the video easy to find and play, and presented their content in a way that supported their marketing goals. Flash Video also integrated well into their overall website, which used lots of other Flash elements. Since they already had Flash programming expertise in-house, choosing Flash Video did not present a huge technology risk or implementation burden. Flash delivery also makes it tough for viewers to store the videos to disk for later viewing, or even sending to a third party, which helps preserve intellectual property rights.
If your website is largely developed in Flash, you're in a similar situation. Designing a custom player is trivial for most experienced Flash developers, and by using Flash Video, you can maintain the integrity of your design.
On the other hand, if you're not currently using Flash and don't have a Flash programmer on staff, you'll find producing and deploying Flash Video more complicated than QuickTime or Windows Media, with no real benefit. In addition, if you want your viewers to share your demo videos, Flash's inability to store videos to disk is a negative. Even if you did make the Flash Video available for download, there aren't any portable players that can play the video, and no real player other than your browser to play it. On a more technical level, Flash Video doesn't scale to higher resolutions as efficiently as Windows Media or QuickTime. That's because the latter two technologies can access scaling and interpolation hardware on your graphics card when scaling to 2X or full-screen, while Flash can't. This means that scaled QuickTime and Windows Media videos will look better and play more efficiently on lower-end computers than Flash.
Strategically, with Windows Media and QuickTime you can encode at smaller resolutions, which preserves quality, and advise your viewers to scale the video during playback to higher resolutions. With Flash, you really should encode at the resolution at which you want the viewer to watch the video. We'll talk more about choosing the best resolution below.
Basically, if you're already using Flash in your website, Flash Video is a good option, but it shouldn't be your exclusive choice. If you're not using Flash, there's little reason to consider Flash Video.
Working with Windows Media
Windows Media playback is ubiquitous on Windows computers, though Mac viewers will have to download Telestream's Flip4Mac plug-in to view the same video files. However, though Microsoft is now beta-testing Windows Media player version 11 for Windows XP, it's stuck on version 9 for Mac OS X and 7.1 for previous Mac operating systems. Microsoft's Windows Media Player for Mac page states, "Microsoft will continue to offer ‘Windows Media Player for Mac' as a download free of charge, but has no plans to provide future updates or product support." Clearly, Windows' platform considerations are driving Windows Media development plans, to the detriment of those seeking to distribute videos to multiplatform viewers.
On a positive note, Media Player 9 worked fine on the Macintosh computers I tested, and Windows Media has great third-party device support for time-shifting playback. Notably, however, the omnipresent iPod does not play back Windows Media files, and Microsoft's past spotty record on Macintosh support, and current hard-line stance via the Macintosh, have engendered strong anti-Microsoft sentiment among Mac users.
Working with QuickTime
Which leaves QuickTime. Between the glow created by the success of the iPod and iTunes and the predominance of QuickTime use in Hollywood for movie trailers, it's a format that connotes quality. Windows users need a plug-in, but most already have it. The QuickTime player makes it dead-simple to save files to disk after you view them; just right-click and choose Save As QuickTime movie. One negative for QuickTime is low-bit rate quality; if you do want to include a low-bit rate video for streaming, use Windows Media and/or Flash Video, not QuickTime.
So, what's the net/net? Include a low-bit rate version for folks who want their video in a hurry and use Windows Media. Include a downloadable file in iPod format, and consider one or two very high-bit rate/high-quality files in QuickTime format. Use Flash Video if you already use Flash, but otherwise it adds little value.
While writing this article, I scanned websites developed by EventDV 25 award winners from 2006 in search of examples of effective web video implementations in the wedding and event video world, and one in particular, caught my eye. Loi Banh of Bluecore Media, offers Flash Video, three versions of QuickTime (small, medium, and large), an iPod-compatible version for download, and a Windows Media version for streaming (Figure 2, left).
This approach satisfies virtually all comers with a variety of choices, from streaming to iPod to high-bit rate progressive download in a format that's easy to save to disk for later viewing. This frees the viewer to choose a high-bit rate version, and the accompanying wait, or a low-rez version that's more accessible.
Now that we've developed a codec strategy, let's review encoding parameters.
Choosing Encoding Parameters
Encoding parameters are the target-specific details you dial in to the encoding program before compression. These include nuts and bolts like frame size, audio and video data rate, frame rate, and encoding technique, all illustrated in Figure 3, left, a screen from Sorenson Squeeze. Let's discuss each in turn.
Your frame size should vary by data rate, with higher resolutions requiring more video data. Your frame size should also match the aspect ratio of your source footage—that is, if you're shooting in 4:3 DV, your output resolution should be 4:3. If you're shooting in 16:9 mode, in either DV or HDV, use a 16:9 output resolution. Table 1 includes suggestions for small, medium, and large videos.
Note that video for iPod is a special case, with prescribed parameters that you have to meet to ensure safe playback on the device. For these files, find an encoder that you trust, like QuickTime Pro, select the iPod output preset, and don't even look at the resolution or other controls (see Figure 4, left).
In terms of data rate, we've already discussed that you can go much higher for files delivered via progressive download. If you have a low-bit rate streaming option, I would go no lower than 400Kbps for the video at the resolutions suggested in . This should produce very good quality with few, if any, noticeable artifacts.
If you opt for medium- and higher-bit rate files, use a data rate that delivers near-perfect video quality. The user chose this quality level, a choice that indicates that she's willing to wait. Start by encoding at the rates suggested in Table 1, and go higher if necessary. In terms of audio, use 64Kbps for QuickTime and Windows Media, 96Kbps for Flash Video (since its MP3 codec isn't quite as powerful).
Your frame rate should match your original frame rate; either 29.97 or 23.98. Don't reduce the frame rate to 15 or 12; this delivers little, if any, quality gain and makes your video look choppy.
Finally, let's briefly chat about your encoding technique. Generally, you'll be able to choose between constant bit rate encoding (CBR) and variable bit rate encoding (VBR). In most instances, VBR encoding will deliver better video quality, with exceptions being very short videos (like under a minute) and low-motion videos like those comprised of talking-head interviews with minimal transitions.
Note that if you're producing Flash Video from the Adobe Production Studio or Adobe Flash Video Encoder, you can only access CBR techniques from these tools. To encode Flash video using VBR techniques, you'll need to use either Sorenson Squeeze or On2 Flix Pro. Otherwise, Premiere Pro should be able to output the required Windows Media or QuickTime files.
If you decide to offer multiple video formats on your website, or videos using the same codec but different encoding parameters, note that Sorenson Squeeze can batch-encode these files in one simple step. Other encoders either don't offer the format support (e.g., Final Cut Pro's Compressor, which doesn't output to Windows Media or Flash) or can't batch (Premiere Pro's Adobe Media Encoder). Though Squeeze has a hefty ($499) price tag, in a high-volume production environment, it should quickly pay for itself.
Let me finish by saying a few words about distribution. You may have heard of programs called video servers, essentially applications that sit on the internet or intranet and dole out videos in response to user clicks. These are invaluable in a corporate LAN environment to protect network bandwidth, and in a high-volume web environment to maximize streaming efficiency to multiple recipients.
However, normal web servers can also distribute video, using the progressive download technique discussed above. You don't need a video server to distribute your videos, and in truth, delivery via a normal server produces an overall better experience.
For example, the Flash Media Server can't deliver video via progressive download, and Flash Video files distributed by the Flash Media server don't cache on the remote viewer's hard drive. This means that if your remote viewer's bandwidth can't smoothly stream your high data rate videos, she may never be able to view a full-quality version. In contrast, when working without a video server, Flash defaults to a progressive download, with local caching and the associated high-quality playback. The best advice for most shops is simply to post your videos to your web server, and don't worry about a streaming server until users start to complain about a bad viewing experience.
Table 1: Suggested Resolutions and Data Rates
|Data Rate||4:3 Resolutions||16:9 Resolutions||Audio Data Rate||Video Data Rate|
Jan Ozer is a frequent contributor to industry magazines on digital video-related topics and the author of Adobe Digital Video How-Tos: 100 Essential Techniques with Adobe Production Studio, published by Peachpit Press.