About DO-IT Video
Over the years, DO-IT has produced more than 40 videos on a wide range of topics related to individuals with disabilities accessing curriculum, using technology, and pursuing challenging careers. Our videos have been available on VHS, DVD, and a variety of online formats. DO-IT videos are also captioned and audio described to increase accessibility for all viewers. Below is detailed information about video captioning, audio description, transcripts, sign language interpretation, and accessible video players.
Captions provide a text version of audio content, synchronized with the video. They benefit people who are unable to hear the audio, people for whom English is a second language, and people who find it easier to process information if they can hear it and read it at the same time. Captions can be either open or closed.
Open captions are burned into the video, and are therefore always visible (they can't be turned off). Historically DO-IT has distributed its videos with open captions in a large font. This ensures that captions would always be available in presentations and lectures, even for users (including instructors, presenters, etc.) who might not know how to enable closed captions, or whose projection equipment doesn't support closed captions. We have always believed our captions should be visible when used in public presentations, since they can benefit audience members who might not otherwise have requested an accommodation, and might not even realize that captions would benefit them. On the DO-IT Video site there are links to download Quicktime and Windows versions of our videos: These versions include open captions.
Closed captions are a separate text track. They have many advantages over open captions:
- Text appearance can be modified. The user can change the color, size, and typeface of the caption text.
- Text can be easily edited. If mistakes are found in the captions they can be quickly changed in the closed caption text file. Edits in open caption formats require re-encoding the video.
- Text can be searched. This inspired us to develop a search feature that makes it possible to search the entire DO-IT Video Collection for specific words or phrases, then jump directly to the point in a video where those words or phrases are being spoken. We unveiled the DO-IT Video Search application in March 2008, and in February 2011 we integrated that application into the main DO-IT Video Collection website.
- Text can be translated. As the accuracy of automatic translation software improves, the ability to automatically translate closed captions into other languages vastly increases the number of people worldwide who can access a video's message. This feature is currently available on YouTube (for examples, see the DO-IT Channel on YouTube). We hope to include this feature on our website in the future.
Audio description, also known as descriptive video, descriptive narration, and other terms, is a narrative track that accompanies a video, describing content that is otherwise presented only visually, thereby making it accessible to individuals who are unable to see the visual content. Audio description, like captions, can be open or closed.
Open audio description is narration that is mixed into the program audio, with careful attention to attaining balance between the two tracks, so the audio description can easily be heard over the program audio. The video is produced with this new audio mix, and the audio description no longer exists as a separate audio track. It can not be turned off without turning off the program audio.
Closed audio description is a separate audio track that is synchronized with the video. As a separate audio track, it can be toggled on and off, and its volume can be controlled independently of the program audio volume.
DO-IT videos are produced with open audio description. Historically, two versions of our videos are available for distribution, one with audio description and one without. On the DO-IT Video Collection website we are actively exploring the feasibility of using closed audio description (see the section on Accessible Video Players for more information).
A transcript is the full text of the video. It benefits users who are deaf-blind who access the web using a Braille output device. It also benefits users who are unable to access the videos for other reasons (e.g., slow bandwidth, technical problems), as well as users who simply want to scan quickly through the content without watching the entire video.
Transcripts should provide access to audio information, but also to visual information in the same way that audio description does. This provides people who are reading the transcript with access to the visual information presented in the video. On the DO-IT Video Collection site each video's transcript is assembled from the closed captions as well as the audio description script. Both are time-stamped, so each block of content can be inserted into the transcript in appropriate sequence. To facilitate navigation, a new paragraph is created each time a new speaker is identified. Audio description is clearly identified as such, both stylistically (audio description appears in a box with a lightly colored background), and with a hidden label ("Audio Description:") that is only accessible to screen reader users.
Many members of the Deaf or Hard-of-Hearing community can access audio content through the English captions. However, for many of these individuals, English is a second language, if they are English-proficient at all. To make video content accessible to these individuals, sign language interpreters can be filmed and displayed in an overlay or in a separate video window beside the video, synchronized with the main video program. DO-IT is currently testing methods for delivering sign language versions of its videos and hopes to have a demonstration available soon on this site.
Accessible Video Players
Many free video players are available on the web, but few are accessible to all users. An accessible player is capable of supporting closed captions and closed audio description, and its controls can be accessed with a screen reader and operated by keyboard, without a mouse. Screen reader accessibility requires all controls to be assigned meaningful labels like "Play", "Pause", "Back 30 seconds", "Forward 30 seconds", "Mute", "Volume Up", and "Volume Down".
Accessibility without a mouse poses interesting challenges. The majority of video players on the web currently use Adobe Flash, and in all browsers other than Internet Explorer, most Flash objects cannot receive focus without the user first clicking on them with a mouse. If a user is unable to do this, they are unable to access the player controls. Therefore, another important feature of an accessible player is that it be controllable with external controls, such as standard HTML links and buttons.
Accessibility also means accessibility across browsers. With millions of people now accessing the web using Apple iPhones and iPads, it is important for a video pleyer to work on these devices. Importantly, these devices don't support Adobe Flash.
The DO-IT Video Collection provides DO-IT staff with an opportunity to explore various video players, in an effort to find that perfect player that meets all user needs. Unfortunately there is currently no perfect player. However, we believe we have found a solution that works reasonably well. The DO-IT Video Collection uses the HTML5 <video> element. HTML5 is currently in draft, and is constantly evolving, but has tremendous potential and already has widespread support among browsers. It includes markup (the <track> element) that enables video to include closed captions, subtitles, and closed audio description. At this point no browser supports these accessibility features natively, but the interface elements are exposed through a powerful application program interface (API), which allows web developers to develop support for these features. The DO-IT Video Collection currently includes support for closed captions through the HTML5 player. We are exploring strategies for providing closed audio description and sign language as well. Meanwhile, open audio described versions of our videos are always played by default, but this can be changed on the user Preferences page. The latest versions of most browsers support the HTML5 <video> element. One late adopter though is Internet Explorer (IE). IE8 does not support HTML5, but IE9 will have support, including support for <video>. Since many people are using Internet Explorer, or older versions of other browsers, a fallback method needs to be provided for these users to access videos. The DO-IT Video Collection is using the JW Player as the fallback player. It's a Flash player that supports closed captions and audio descriptions, and has a good API that allows us to control the Flash player using standard HTML buttons. In fact, we use the same set of player control buttons for both the HTML5 and JW Players, so all users get a reasonably consistent interface.
Here's what we're working on:
- Subtitles on all videos. Our videos are currently being translated into Japanese and Spanish. We're hoping to translate into other languages as well.
- Automatic translation available on the fly using Google's Translation service.
- Support for closed audio description in the HTML5 player
- Sign language to accomopany at least one video
Send Us Feedback
Do you have recommendations for additional features? Suggestions for how we might design this application to be more accessible and usable? Please let us know what you think. Send suggestions to Terrill Thompson.