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Web Accessibility: Audio and Video on the Web

Last week, I described what it means for a Web site to be accessible to people with disabilities (see "Web Accessibility: Surfing the Web Blind" in TidBITS-571). Everything rests on the way Web pages are coded and the adaptive technology a disabled Web surfer uses to read the page. Things are slowly improving, but conditions are not good in general. Web accessibility essentially refers to access for blind and visually-impaired people, but few Web authors even know about accessibility, and fewer still take the time to do things right. Meanwhile, with only one screen reader (a program that reads text, menus, and the like aloud) available for Macs - and which doesn't work well with Web sites - blind computer users are better off using Windows.


But all that pertains to Web sites containing nothing but text and graphics. What about sites reliant on those sexy QuickTime movies or Flash animations?

Multimedia Access -- Any kind of online video presents severe accessibility problems by being inaccessible to the deaf (who can't hear the audio) and to the blind (who can't see the video).

What to do? Here we must borrow a trick or two from older media. Television and film have grappled with accessibility for decades, and since the forces of convergence are trying to make the Internet look a lot like television, the lessons are transferable.

You make video accessible to deaf and hard-of-hearing viewers through captioning: transcription of dialogue and rendition of other relevant sounds. Captioning isn't the same as subtitling - among other differences, subtitles are often used for language translation (captions use the same language as the audio) and subtitles render only speech, and not always all of it, either.

<http://www.joeclark.org/ understanding.html#subtitling>

Captions are usually "closed" - you need a decoder to make them visible. Canada, the United States, and a select few other regions use one system (called Line 21), while Europe and pretty much everywhere else use a different system (called World System Teletext). The systems are incompatible, but then again, telecasts themselves are incompatible between continents. Gary Robson's Caption FAQ will tell you more.


If captions are part of the original video footage and can't be turned off, they are said to be "open." There isn't much open captioning these days, while nearly all subtitling is open. More than just video can be captioned: captioning in first-run movie theatres is up and running, but hard to find.


Meanwhile, you can make video accessible to blind and visually-impaired viewers through audio description, in which a narrator, working from a tightly honed script, describes out loud the character movements, settings, costumes, titles, and other visual information needed to understand what's really going on. The descriptions are usually delivered during natural pauses in dialogue. The largest sources of audio description are on television - on PBS and the Turner Classic Movies channel, both in the United States. WGBH, Boston's public broadcasting channel, and The Kennedy Center offer a taste of audio description online.

<http://main.wgbh.org/wgbh/access/dvs/ dvsclip.html>
<http://kennedy-center.org/multimedia/surface/ home.html>

If you can play Region 1 DVDs, you can watch subtitles and listen to audio descriptions on the only DVDs with audio description, Terminator 2 and Basic Instinct. (They work fine on a DVD-capable Mac.) Also, a new three-disc DVD set from PBS, Abraham and Mary Lincoln: A House Divided, is due in March 2001 featuring captions, DVD subtitles, audio descriptions, and, for the first time, audiovisual interface menus.

<http://main.wgbh.org/wgbh/access/dvs/ presspage.html>

Sounds good, doesn't it? But there are a few hiccups.

There is no longstanding production experience in multimedia accessibility. Captioning and DVD subtitling is comparatively cheap - in the hundreds of dollars an hour range - but if your site isn't affiliated with a rich television network or production studio, that figure ceases to be cheap. Audio description is cheap only in movie-budget terms, running about $10,000 per motion picture. Costs will continue to go down, but only gradually. Another complication linked to the knowledge gap: multimedia authors should not try to caption, subtitle, describe, or dub their own productions, because they're virtually guaranteed to get it wrong. So authors are stuck: the quality won't be up to snuff if they try to do it in-house on the cheap, but outside services cost good money, and very few do work for online media.

Online systems for closed captioning and audio description are poorly supported. It is possible to embed captions in a QuickTime movie, and there's an entire HTML-like syntax for marking up captions and audio descriptions (called Synchronized Media Interchange Language or SMIL), but incompatibilities are rife. There are so many online video players out there (QuickTime, RealVideo, Windows Media, etc.), with so many versions, that you cannot rely on your visitor to have the right plug-in or software. Plus, Apple's documentation for SMIL support in QuickTime 4.1 spends a lot of time explaining how it can be used to embed advertising but no time discussing accessibility applications.


Making audio descriptions hidden (so you can turn them on and off) is difficult or impossible in the various online formats. In any event, closed accessibility is unnecessary in multimedia. With technologies like Akamai that distribute large files over many servers to speed up delivery times, and with disk space so cheap these days, it makes more sense to offer separate versions of an online video with open access features that can't be turned off. You simply select a captioned (or subtitled, or described, or dubbed) version from a menu and that's the one you watch.


Another hiccup is that nobody's making captioned or audio-described video. Period. It just isn't happening. Virtually all the "content" that's available takes the form of brief demonstration projects.


Why not? There are very few tools. Adobe Premiere and similar authoring programs don't let you create captions and audio descriptions. (You can kludge together some titles, but how long are you going to put up with a kludge?) One specialized tool, MAGpie, works only on Windows.

<http://main.wgbh.org/wgbh/pages/ncam/webaccess/ magpie/>

Existing companies and organizations that caption and describe TV shows and videos are generally incapable of doing the same for online media. The Caption Center and the Descriptive Video Service at WGBH are pretty much the only options.


The Knowledge Gap -- But the technical issues are nothing compared to the knowledge gap. Captioning and audio description (and two related techniques, subtitling and dubbing) are fiendishly difficult. You thought designing Web pages was hard? Captioning isn't anything remotely resembling simple transcription, and have you ever tried to sum up a scene of your favourite TV show in five seconds or less? There are, moreover, no training materials or courses available to teach captioning, audio description, subtitling, or dubbing (save for one limited course in description in the U.K.).

Two recent technologies, Macromedia's Flash and burning your own DVDs, have thrown a spotlight on the knowledge gap.

Flash, the nearly ubiquitous, widely misused multimedia authoring tool, has single-handedly spawned an Internet catchphrase: "Skip intro." Flash animations are inaccessible, period. There is no way for a screen reader or other adaptive technology to interpret Flash "content." Even demonstration projects in Flash, such as one at the University of Toronto's SNOW (Special Needs Opportunity Windows) project, access come equipped with a range of instructions and caveats.


Macromedia has, however, finally admitted it has a problem, and the company now maintains impressive-looking pages devoted to Flash accessibility. Unfortunately, having read all the Macromedia materials and spoken at length with the fellow running the access project, it is pretty clear that Macromedia does not itself understand the issues involved with access, let alone the difficulty of training Flash authors. And even if the technology provided bulletproof, reliable access to alternate versions of Flash content (like captioned or described variants), Flash artists have no training materials or programs available to learn how to create the alternate versions.

<http://www.macromedia.com/macromedia/ accessibility/>

Then there is the capability to burn your own DVDs. Steve Jobs made a big splash earlier this year at Macworld Expo San Francisco 2001 with iDVD and DVD Studio Pro, Apple's software that lets consumers and professionals assemble and record their own DVDs using the SuperDrive available on high-end Power Mac G4s. DVD Studio Pro lets you encode multiple audio tracks and subtitle streams. That's great, however, just because you can add these features to your DVD media doesn't guarantee accessibility. Poorly done captions and descriptions can be worse than none at all.


What about Napster? No discussion of multimedia on the Web would be complete without addressing Internet radio stations, Napster, and anything else that's audio-only. Here the group chiefly affected is deaf and hard-of-hearing people. Although music videos on television and home video in North America can be and are closed-captioned (they're audio-visual), there's no way to make traded music files accessible.


Online audio files that contain speech, however, can be transcribed, and indeed this is the preferred method for academic lectures (think electronic learning ventures) and literary readings. It is conceivable to encode visible captions in a QuickTime stream that includes audio only, but no one's doing it. (You can also encode the transcript as a SMIL file, with attendant incompatibilities and knowledge-gap issues.)

Another issue is the accessibility of plug-ins themselves. Streaming audio is attractive to blind and visually-impaired people, but you still need to control the QuickTime (or RealAudio or Windows Media) player, probably using a screen reader and keyboard commands. QuickTime keyboard equivalents on the Mac are skimpy and controlling QuickTime media often requires direct manipulation of images a blind person couldn't necessarily see. RealPlayer Plus keyboard shortcuts are extensive, though more so on Windows. If Windows Media Player has any keyboard shortcuts at all, they're not documented online.

<http://www.apple.com/quicktime/resources/qt4/us /help/sc/pgs/scShrtct.htm>
<http://service.real.com/help/player/plus_ manual.8/htmfiles/ keyboardshtcuts.htm#14791>

Nothing but Trouble -- So there's trouble in paradise when it comes to accessibility. Everywhere you look - adaptive software and hardware, Apple's own corporate support, developer commitment, Web design, browsers, multimedia - on Windows, the situation is always at least noticeably less bad and often clearly superior.

Discouraging, all this. But it doesn't have to be this way. After twenty years of watching captioned, described, dubbed, and subtitled TV, writing about it, lecturing and hectoring over it, and obsessing over it, I know from experience that a certain minority of non-disabled people really get accessible media.

Try it yourself: watch all your television and home video with captions (or DVD subtitles) turned on for a good two weeks. (No cheating. Two weeks. Nearly all recent televisions come equipped with caption-decoding chips in North America, Europe, and elsewhere.) You'll quickly find you have developed new skills in reading, listening, and watching simultaneously. There's modest experimental evidence that even people entirely new to captioning become proficient at understanding TV even with the new information track.

<http://www.joeclark.org/research- roundup.html#eye>

By the way, in North America deaf captioning viewers are now the minority. Even with the poor typographic quality of captions and DVD subtitles, and the many technical limitations, watching a video stream with captions or subtitles is a much richer experience.


But you know what would really help? Some mojo from Steve Jobs. What odds do you give that Steve Jobs is the kind of person who truly gets accessible media, or would get it if properly introduced? Jobs is already a media tycoon and an evangelist for desktop movies on the Mac. He needs a few demonstrations of what accessible media - and, for that matter, adaptive technology - can do on a Macintosh. Would he then get religion and bring all of his powers of expression to bear, making it cool?

With that kind of imprimatur, wouldn't we finally see some real action on the issue of accessibility on the Macintosh?

[Joe Clark is a former journalist in Toronto who's followed, written about, and worked in the disability field for two decades. Explore his many online accessibility resources at his Web site.]



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