Captioning online video – it’s not as hard as you might think

Recently I was giving a lecture to a group of students about web accessibility and discovered that just before my presentation, a heated argument had erupted in the class about the relevance of accessibility if the content of a website was perceived to be irrelevant to a person with a disability.

An example used was whether or not a website designed to sell cars should be made accessible to people who are blind given that they can’t drive. It occurred to me that the student who gave the example would probably make a similar argument for accessibility features necessary to support people who are hearing impaired on a website that had audio-visual material.

Where the student’s argument falls down, aside from the understandable ethical one, is that you will never entirely know the reason why someone has come to your website. In the car example, it may be the case that a vision impaired person may want to buy a car for someone else, is a car enthusiast or any one of a number of other reasons.

If we think less about rationalising why something isn’t accessible, and just incorporate accessibility by default, then whatever the reason is for someone wanting to visit a website, they will be able to achieve their objective.

Although this example is vision-related, it did remind me that out of all the requirements of WCAG 2.0 Level ‘A’ compliance, the one point where ICT professionals often draw the line is when it comes to captioned video.

While most other guidelines require minor changes to coding practices, captioning video is seen as one thing that doesn’t become a default part of building a website and the justifications for not needing to do it come thick and fast. Arguments against captioning that I’ve heard include:

  • There’s too many video standards to do captions properly 
  • It’s too expensive
  • It’s too time-consuming
  • Hardly anyone captions video, why should I do it?
  • WCAG 1.0 didn’t require captions, and our organisation hasn’t moved to WCAG 2.0

While some of these arguments may have held up in the past, none of them hold up today. 

WCAG 2.0 Level ‘A’ requirements for online captioned video

The requirement under WCAG 2.0is pretty straightforward. It states:

1.2.2 Captions (Prerecorded): Captionsare provided for all prerecorded audiocontent in synchronised media, except when the media is an alternative for text and is clearly labelled as such.

This means that if you have a video with an audio track, it must contain captions.  It doesn’t matter too much whether the captions are open (visible by everyone) or closed (can be toggled on or off) but they must be present. 

The inclusion of captioned video in WCAG 2.0 was one of the most significant steps forward in accessibility over WCAG 1.0.  When the original guidelines were released in 1999, you can appreciate that the bandwidth and coding options of the late1990s HTML meant that it would have been challenging to include captions at that time.

WCAG 2.0 addressed this by December 2008 when WCAG 2.0 was released;web technologies and bandwidth had caught up to effectively support this requirement. This may help explain why the arguments about WCAG 1.0 are no longer valid. It also explains why captions aren’t as prevalent on the internet as it is on other technologies – it has only been a WCAG requirement for three years.

That said, the amount of captioned video online is increasing at a rapid rate and it’s important for developers to be a part of that process.

Which formats support captions?

The argument about captioned video being ‘too hard’ because of the multiple video formats is another issue that may have been a problem in the 1990s but is no longer an issue today. All major formats including Flash, Windows Media, QuickTime, Ogg, Real and many other provide support for closed captions, and the authoring tools associated with these formats generally support the creation of closed captions so there’s a very good chance that the tool you’re using right now for your work will allow you to create online captioned video.

There’s also exciting developments around time-based media as part of the HTML5standard which is likely to standardise and streamline caption creation. Further information on caption formats and file types can be found in the Practical Web Accessibility section of the Media Access Australia website.

Captioning online video the easy way – YouTube automated captions

While most authoring tools will provide you with the ability to create a captioned video, there is an easier way. YouTube has the ability to automatically caption videos that contain spoken English and Japanese using its own speech recognition software.  While the captions aren’t necessarily accurate, it can save a lot of time and the file that contains the captions can be downloaded for editing.

To request YouTube to caption your video, simply sign into YouTube, upload your video and select the ‘Request processing’ button in the subtitles section. Your video will be captioned in about 24 hours. You can then either keep the video on YouTube or download the caption file for your own projects.  

Free captioning tools to create or edit captions

If you wish to download your automated captions for editing or wish to create a new captioned file, there are a number of free online tools which can help out, including:

  • Overstream: a popular web-based captioning tool
  • CaptionTube: a web-based captioning tool designed specifically for YouTube

There is also a good video tutorial on how to use Overstream available on YouTube.

Examples of captioned online video

The final argument in the list is that there’s not a lot of captioned video content online. While it’s true and as mentioned previously, it’s only been with us as a requirement of WCAG 2.0 for three years, there are many examples of captioned video online.

In addition to the massive amount of captioned resources available thanks to YouTube, many of the catch-up TV services around the world now support captioned video, such as the BBC iPlayer. Closer to home, the ABC iViewservice replicates the captions available on ABC TV.

Looking at the common arguments made against captioned video now, it’s clear that they have little relevance:

  • all major video formats support closed captions
  • YouTube can do most of the work for you, taking away the time constraints
  • the cost issue is removed with free captioning tools available online
  • there’s a lot of online captioned video if you look in the right places
  • and it’s important to follow the WCAG 2.0 standard

It’s my hope that in the not-too-distant future, the creation of captions will become the default position for ICT professionals and it will just be taken for granted as a natural part of the development process in the creation of online content.

W3C news

The W3C have released before and after demonstrations of web accessibility. The Before and After Demonstration (BAD)shows an inaccessible website and a retrofitted version of the same website with the accessibility barriers fixed. BAD is especially useful for presentations.


Dr Scott Hollier represents Media Access Australia on the W3C Advisory Committee and publishes the W3C Column monthly.

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