The above video, Captions: Improving Access to Postsecondary Education, features faculty, staff, and students from the UW discussing the importance and benefits of captioning videos in higher education. This video is also available in a fully accessible media player with interactive transcript, audio description, and other accessibility features on the DO-IT Video website.
Videos should be produced and delivered in ways that ensure that all members of the audience can access their content. Accessible video includes the following features:
- Transcript — A text version of the audio or video content. A transcript should capture all the spoken audio, plus on-screen text and descriptions of key visual information that wouldn’t otherwise be accessible without seeing the video. Transcripts make video content accessible to everyone, including people who unable to view the video due to accessibility problems or technical limitations. They are are also helpful for people who want to quickly scan or search a video’s content but don’t have the time to watch the entire video. Transcripts can be interactive, enabling users to click anywhere in the text to watch the video starting at that point.
- Closed captions — A text transcript of the audio content, synchronized with the video. Captions provide many benefits. They are essential for ensuring your video is accessible to students, employees, and members of the public who are deaf or hard of hearing. They also help non-native English speakers to understand the video, make it possible to search for content within the video, help all students learn the spelling of technical terms spoken in the video, and make it possible to generate an interactive transcript where users can click anywhere in the transcript to watch the video where that text is spoken.
- Audio description — A separate narrative track that describes important visual content, making it accessible to people who are unable to see the video. Individuals who are blind can understand much of a video’s content by listening to its audio. However, if a video includes content that is only presented visually (e.g., on-screen text or key actions that are not obvious from the audio) this visual information must be described in order to be accessible to people who are unable to see it.
- Accessible media player — A player that supports captions and audio descriptions, can be operated with keyboard alone for people who are unable to use a mouse, and has buttons and controls that are properly labeled for people using assistive technologies such as screen readers.
Following are recommendations for how to produce and deliver video that has these accessibility features. They were written specifically for people producing or delivering video at the University of Washington, but can serve as a helpful resource to people outside the UW as well.
How to caption video
There are two general approaches to captioning video:
- Outsource. Companies such as Automatic Sync Technologies, 3PlayMedia, cielo24, and many other captioning service providers will caption videos for a fee. The UW has a contract with Automatic Sync Technologies. See Captioning UW video with CaptionSync for additional information.
- Do it yourself. There are free tools available online that make it possible and easy to caption your own video. See Captioning your own video for free for additional information.
The end product generated by both options is a caption file. Most caption files are plain text files with time codes indicating the start and stop times. However, there are various types of caption files with slight variations in their syntax. After you have a caption file, the final step is to add this file to your video. How you do this, and the types of caption file supported, depends on where your video is hosted. Select one of the following options:
- Adding captions to YouTube videos
- Adding captions to videos on web pages
- Adding captions to videos in Panopto
- Adding captions to videos in Canvas
How to add audio description to video
Like captions, there are two general approaches to producing audio description for video:
- Outsource. The American Council of the Blind has compiled a comprehensive list of commercial services for producing audio description. If the video contains a lot of visual information, this may be the best option since describing video effectively is an art form that requires specialized skill. Typically these service providers will produce a new video that has the descriptive narration mixed in with the program audio. Then you can provide your video in two formats: One with audio description and one without.
- Do it yourself. For videos that have very little visual information, the same free online tools that are used for creating closed caption tracks can also be used for creating description tracks. Description tracks are essentially the same as caption tracks—short blocks of text with timestamps that synchronize the text with the video—but their function is different. They are intended to be read aloud by screen readers, rather than voiced by a human narrator. Playing video with text-based audio description requires a media player that supports this feature, such as Able Player, the open source media player developed at the UW. For additional information about free online tools for captioning and describing video, see Captioning your own video for free.
Supplementing video with a transcript
If you have captioned your video, a transcript is available as one of the optional output formats produced by the closed captioning process. This is true of both the free online tools and the commercial service providers. To make the transcript available simply link to it from your web page, wherever you link to or display the associated video.
Able Player, the accessible open source media player developed at the UW, generates an interactive transcript automatically using the caption and/or description tracks. For additional information see the following section.
Choosing an accessible media player
When choosing how to deliver your video, it is important to consider options that are fully accessible. Whether you are selecting a media player plugin or module for your website or selecting a service to host your videos, the following questions should be answered about the available options:
- Does the media player support closed captions?
- Does the media player support audio description in a way that enables users to toggle the narration on and off?
- Can the media player’s buttons and controls be operated without a mouse?
- Are the media player’s buttons and controls properly labeled so they can be operated by a blind person using a screen reader?
- Is the media player fully functional, including all its accessibility features, across platforms and in all major browsers?
One player that satisfies all of these criteria is Able Player, a free, open-source media player that was developed at the UW with accessibility in mind. For additional information see Able Player on Github.