Making Videos Accessible
Video is one of the mediums that requires the most attention concerning accessibility. The visual content of video is lost for students with visual impairments, and the audio content is lost for students with hearing impairments. These caveats necessitate providing alternative textual representations of audio and critical image content. This can be accomplished by creating a caption script and visual script for a video.
A caption script is a text file that contains the spoken portion of the video and timestamps that tell the computer when during the video to display the captions.
Here is an example of a video that has a caption script (Turn on closed captioning by clicking the "CC" button in the bottom-right of the video window):
Captioning videos that you create
If you are the creator of the video, you hold copyright and have access to the raw video file (MOV, MP4, M4V, AVI, WMV, etc.). This is beneficial, since having that raw file gives you the most options for creating a caption script for the video.
YouTube has a very intelligent captioning capabilities built right into their video manager. You can upload your video to YouTube, and if it detects a person speaking in the video, it will attempt to generate an automatic caption script for the video. Usually, this script needs a bit of cleaning up, and sometimes it doesn't correctly detect speaking and no script is generated. Creating a new caption script or editing an automatically-generated one can be done right in the browser.
If you want to caption your video but do not want it to be publicly findable on YouTube, you can change your video's permissions so that only people to whom you give the web address will be able to view it. If you do not want your video to be hosted on the web at all, you can upload it, complete captioning, save the caption script to your computer, and delete the video from YouTube. You can then provide the caption script that you created to your students when you give them the video.
Google offers in-depth instructions for adding and editing captions for a video. They update their documentation every time they update YouTube's captioning capabilities.
Captioning videos from around the web
To add captions to a video that either you have created or is hosted somewhere on the web (YouTube, Vimeo, etc.), the easiest method is to use Amara. When you plug a video's URL into Amara, it will take you through a step-by-step wizard for transcribing the audio in the video and determining when the text should appear on screen. It then creates an accessible video player in which the video will play with the captions. Here is an example of a video captioned by Amara. Amara video players can be embedded into most webpages and course management tools. To caption a video with Amara, just paste your video's URL into their wizard, and the site will guide you through the rest.
Vision-impaired students will not be able to see any of the critical visual information that might be contained in a video. A visual script is a text file that describes any important visuals and has timestamps that let the student know at what point in the video those visuals appear. The student can use screenreader software to listen to the video and pause it at the times listed in the script for visuals to be described aloud.
The easiest way to create a visual script is to watch through the video and manually mark down the times at which important visuals appear and describe them. You can then provide that file to students when you give them the video or include it as a link beneath a video embedded in a webpage or course management tool.
Imagery that is intended for aesthetic purposes only or that does not contribute to the knowledge intended to be taken away from the video does not need to be scripted.