Accessible Media Captions & Transcripts

To make videos and audio accessible to everyone we need good and descriptive text representation of what a user might be missing if they were deaf or had any level of hearing loss. These issues are covered in WCAG’s success criterion 1.2.2 A, 1.2.4 AA, and 1.2.9 AAA.

Captions (1.2.2 A)

Since captions are level A it is something we should all strive to do in our videos. This process involves providing both text for every spoken word, and also describing what is happening in the video if it is relevant. Music, sound effects, and who is doing the talking can all relevant.

There are several different file formats for captions but the most common are VTT (Web Video Text Tracks) and SRT (SubRip Subtitle). They are basically plain text files that have captions listed in sequential order and include timestamps of when each line started and stopped. VTT is a little bit cooler because it allows the user to alter how and where the captions are placed.

Caption files are not particularly easy to generate. They are also time consuming, but there are people out there who will do it for you for a fee. There are several AI tools that will do it for you. The captions need to be perfect. AI, or even a third party person or company, won’t always know what you intend. So, you should always do a final review.

YouTube Captions

If you happen to host your videos on YouTube then you can easily obtain captions that way, and for free! Once you’ve uploaded your video, give it a day, maybe two, and they will automatically transcribe your video. Once that is done you can easily edit the text to make sure it’s all correct. If you need the VTT or SRT file, you can download it.

How to generate captions on YouTube:

  1. Upload video and wait
  2. Go to your YouTube Studio
  3. Click “Subtitles” in the menu
  4. Select the appropriate video
  5. You will see a row for (automatic captions), hover over the Subtitles column and click the pencil which is “Duplicate and edit”
  1. Fix any typos or misunderstandings then save
  2. Your new captions will be on the list.
  3. Hover over the Subtitles column again and click the 3 dots
  4. Click download
  5. Choose a file format

Your video edit might also provide this service. Here are instructions for adding captions with Adobe Premiere.

Live Captions (1.2.4 AA)

Live captions are significantly more difficult. If you’ve ever live streamed on Facebook, you’ve noticed they try to provide live captions. It’s not perfect but I think it’s pretty good. For everyone else they actually hire a person who is a trained stenographer. They use a special keyboard that has phonetic symbols on it. Then the software converts it to actual words. That’s why we see a slight delay in captions when watching live television. These stenographers strive to be at least 98% accurate.

It’s unrealistic for most of us to hire someone full time to do this. Thankfully most 3rd party companies provide AI tools to deal with it.

Live Audio-only (1.2.9 AAA)

This follows the same rules as 1.2.4. Honestly, this criterion doesn’t seem to be fully planned out and might be why it’s rated as AAA. As long as you are providing some sort of transcript in real-time you will be fine. AI is definitely the way to go on this if you’re the little guy, like me.