4. Manual Testing Strategies
Another element of web content that is typically examined manually is multimedia. There are three potential accommodations that can be found with various media: captions, audio description, and transcripts (and combinations of these, depending on the media).
All video with meaningful spoken dialogue must include captions that reproduce the verbal elements of the video. Depending on the jurisdiction you are in, video may also require audio description (referred to as described video for television) – an audio track added to the video that describes the action or context of the video that one would not be able to determine by listening. The third element is an optional transcript, made available as a separate file that can be downloaded or reviewed online on its own.
Adding captions to a video is a fairly straightforward process, with the right tools. Services like YouTube provide built-in tools that allow video producers to add captions directly through the YouTube video manager. Many video production programs also include tools for creating captions. The Amara caption editor, which will also caption YouTube videos, can be used to caption videos from other sources on the Web. It generates a caption file that can be imported into video editors or players, to quickly add captions. It is also relatively straightforward to convert the caption file into a transcript, by removing the time codes from the caption file.
One word of caution regarding services that provide automated captions: these captions do not satisfy the success criterion associated with Guideline 1.2.2 Captions (Prerecorded) Level A. They may be a helpful strategy to consider in cases when a video must be posted in a hurry; however, in many cases these automated captions have a very high error rate, and provide little accommodation for those who require them. Only human-generated captions are acceptable to meet the requirements of this guideline. One of the most useful aspects of automated captions is that they are a good starting point for human-generated captions. They can be exported from YouTube into Amara where they can be refined, then exported back to YouTube. However, the more errors automated captions have in them, the less useful they become as a starting point for human-generated captions. With an error rate of about 35% or worse, you are better off captioning from scratch.
For more on how to use the YouTube and Amara caption editors, view the videos below.
© Noah’s World!!!. Released under the terms of a Standard YouTube License. All rights reserved.
© Amara Subtitles. Released under the terms of a Standard YouTube License. All rights reserved.
Examining the accessibility of audio content is straightforward. When audio with meaningful spoken information is presented, a transcript must be provided.
It is also possible in some cases to caption an audio track if it is being presented in a player that supports captioned audio. Provide captioned audio where possible, but also be sure to include a transcript.
Figure: Example of captioned audio