Captions
Video is a great way to reach your audience. Many users prefer video over text, and in many European countries, around 25 % of the adult population has difficulty understanding written text. Therefore, video is important.
But in order for the video message to reach as many people as possible, it must be accessible. Captions is one of the most important things to think about. Captions are necessary for people who have a hearing impairment and a great help for many others. Many users chose to watch video with the sound turned off.
What should be captioned?
In order for captions to comply with the requirements of the Web Accessibility Directive, all relevant audio information must be subtitled in pre-recorded video. Not just speech, but also other sounds that are important for understanding.
If a train happens to honk in the background of an interview, that information adds nothing to the understanding. But if the film is about trains and we see a train honking, then it may be relevant to describe. Preferably in brackets: (The train honks).
Timing and line lengths
In order for the reader to read the text, each line must not be too long, and it must stay visible long enough to read.
Recommendation for line lengths:
- Maximum two lines of text
- Maximum 42 characters per line
- A total of 84 characters
Recommendation for timing:
- A row of 3 seconds
- Two rows for 6 seconds
- At least one second for one-third line
If you write exactly everything that is said in the video, the lines are very likely to be too long. Therefore, it is good to simplify, which is an art in itself.
Captioning tools
Funka and the Swedish National Association of hearing impaired have examined tools and methods for captions that will be presented at the Funka's Accessibility Days. There are many different tools, some automatic other manual, some free while others cost money. Many of them are good, but we like Amara Editor, a free online tool. YouTube's built-in tool is also easy to use, especially if you are going to caption movies in languages where automatic captioning can be used as support.
There are many success criteria and requirements that are linked to video content, but this tip is only about the actual captioning of pre-recorded film, which is covered by:
WCAG. 2.1 (AA)
1.2.2