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The single most important thing to do when creating accessible video is creating captions. Captions are subtitles which can be added to video to describe its audio component. Dialogue and sounds relevant to the video must be added in subtitles to accommodate people with disabilities. While the obvious advantage of captioned video applies to people with hearing disabilities, captions can help all people. Captions can also help people without disabilities understand the content of the video as well – especially if the ambient noise of the video sometimes overcomes the dialogue. For example, second language English learners might have an easier time reading English than understanding English spoken aloud.
- Closed: permanently incorporated into the video. If the author desires to make changes to the captioning, this can be difficult as the text is combined directly with the video.
- Open: can be toggled on or off (like on YouTube). Having open captioning allows the author to change the captions much easier.
- Use one or two lines of text
- Caption the exact wording of speakers, including slang and grammatical errors
- Only occasionally edit a few words to facilitate reading speed
- Caption sound effects that contribute to the understanding of the content
- Synchronize captions with the aural content
- Only occasionally change the location of captions on the screen
- Use a simple sans-serif font, such as Helvetica, and proportional spacing
- Ensure high contrast between the text and background
- Use both uppercase and lowercase letters
- Use italics to indicate the narrator, off-screen voices, sound effects, and other vital information presented aurally
How to Caption Videos
Depending on what video player you are using, you will have to generate a specific type of caption file.
- Windows Media: SAMI file
- RealPlayer: RealText file
- Quicktime: Quicktime format file
You can use MAGpie (Media Access Generator) software to generate these specific caption files, and then use video editing software to add caption files to a video. MAGpie does not generate the captions – it is up to you to transcribe the videos. MAGpie is useful in that it creates the caption file for you, based on the caption text you have typed into its system. By creating the caption file, it saves you a lot of time.
- MAGpie 1.0 (free)
- MAGpie 2.0 (free)
- All versions of MAGpie are available for download here: NCAM MAGpie Download Page
- There are MAGpie versions for all versions of Windows, and MAGpie 2.0.2 can run on non-Intel or pre-Leopard Macs (not later than OS 10.4.x).
- Detailed instructions for using MAGpie 1.0 are available here: WebAIM MAGpie 1.0 Instructions
- Detailed instructions for using MAGpie 2.0 are available here: WebAIM MAGpie 2.0 Instructions
Transcripts of the captioned text should be made available as well. This is especially handy for those with visual disabilities, to allow them to go over the text with their screen readers afterwards. It is also useful for those without disabilities. Again, a second language English learner may find it easier to understand English by reading rather than by listening. Transcripts also allow people to review the material presented in the video without having to re-watch the whole thing.
Transcribing the video is a part of the captioning process. Whether you transcribe while you're imputing the text in captioning software such as MAGpie, or whether you do it in advance, you can save the transcript in an accessible Microsoft Word file and make it available to users.
If you include any important visual information in a video, you may find that including audio descriptions of that information can be useful. Audio descriptions are a spoken word description of a visual element which may appear on the screen (such as a graph). However, if you include the description of the visual element either in the audio of the video itself or in its captions, having separate descriptive audio is unnecessary.