Video content accessibility (audio descriptions, etc)

Flashing or flickering content in a video can create an immersive experience – but could also have dangerous consequences for some viewers. Partners need to be careful to limit the risk of triggering seizures.

Who is this helping?

People who have photosensitive epilepsy can have a seizure triggered by content that flashes at certain frequencies for more than a few flashes. Photosensitive epilepsy is most prevalent in children and young people with epilepsy.

Other people without epilepsy may have other symptoms triggered by flashing content (e.g. headache, nausea, dizziness, etc.).

What is considered harmful flashing content?

Some examples of flashing content may include but are not limited to:

• Nightclub scenes with strobe flashes
• Fast cuts between bright and dark scenes
• Close-ups of rapid-fire explosions
• Bright red flashes that take up most of the screen

Patterns that flash or move quickly can also cause issues for photosensitive viewers.

See the WCAG criteria 2.3.1 Three Flashes or Below Threshold and the ITU BT-1702 specification for details.

How can I minimize photosensitivity issues?

The safest option is to avoid flashing content in your videos. If some flashes are a necessary element in your video, you will need to limit the risk:

• Space out the time between flashes (fewer than 3 flashes per second)
• Reduce the overall brightness of each flash
• Keep the area of flashing content small
• Use professional software tools or a third-party service to run a PSE test that detects harmful flashes and patterns. (These tests are often required in TV broadcast, film and gaming industries around the world.)
• Add a warning for photosensitive viewers
  
  

Where can I set up a warning for photosensitive viewers?

We have an item on our Studio roadmap to add a checkbox during video upload/edit, to allow Partners to flag their own photosensitive content. This will display a photosensitivity warning for that video in the Player.

Until this feature is developed, we recommend you add a warning directly to the beginning of your video (prior to upload), to your video descriptions, or to your video posters.

Relevant WCAG criteria

• 2.3.1 Three Flashes or Below Threshold – level A

Text transcripts are a text version of the speech, sound and visual information needed to understand a video. Transcripts are an alternative to video, and may be viewed without having to play the video at all.

Who is this helping?

Transcripts are important for people who are deaf, hard of hearing, have difficulty processing auditory information, but also for people who are deaf and blind.

Transcripts are also useful for anyone who prefers to consume content in text format. They can also provide SEO benefits by making your video content accessible to search engine crawlers.

What does a transcript look like?

A transcript can be formatted in different ways, but it will usually contain speaker identification, descriptions of visuals, and all the audio.

Below is a partial transcript for the open source movie Cosmos Laundromat:

Victor    Excuse me.
          (The voice comes from a character not visible on screen.)
          Excuse me, sir. Sir?
          (A man appears in the background.)
          Excuse me?

Franck    Oh, come.

Victor    Do you have a moment, sir?

Franck    I'm kind of in the middle of something here.
          Yes, thank you.

Victor    I've come a long way for you, Frank.
          (After a while, Franck turns around.)

Victor    My name's Victor.
          (Victor puts his hand over his heart.) 
          Hi.
          And you are...
          You are Frank.
          You are so much more than just a sheep, aren't you?

Franck    Oh, yeah.
          How would you know?

Victor    Look at you. You're an adventurer, Franck. 
          Just like me. You're a lone wolf. 
          (Victor slowly moves closer to Franck.) 

          Tell me, does one choose to be alone? 
          (Victor keeps moving closer to Franck.)

          No, one doesn't. 
          One doesn't even choose to be a wolf. 
          Or does one?
          (Closeup on Victor's face, then closeup on Franck's face.) 

How to create a transcript?

If your video already has captions, those can be used as a starting point to create a transcript: you will just have to add any essential visual information as well as speaker identification, to ensure viewers reading your transcript get the same information as others who watch the video.

If you don’t already have captions, you’ll need to transcribe your video. Manual transcriptions created by professional transcript service providers are best for this. AI-powered speech-to-text transcriptions can be used as a starting point, but will need human editing to ensure they make sense.

Where to put a transcript?

It is recommended to include the full transcript on your page right under the video.

Alternatively, you can add a link to the transcript, which would also meet WCAG requirements – as long as the link is easy to find.

If you want the transcript to be less prominent on your page, you may want to place it inside a tabbed interface, or inside a component that can expand and collapse when the user activates it via click or keypress. If you do choose this option, make sure that those components also meet WCAG requirements (see accessible design patterns for tabs and show/hide widgets).

As long as the full transcript for a given video is of good quality and can be found and consulted in an accessible way, your content will meet the WCAG requirements about text alternatives for videos.

Relevant WCAG criteria

• 1.2.1 Audio-only and Video-only (Prerecorded) – level A
• 1.2.8 Media Alternative (Prerecorded) – level AAA

See more information about transcripts from the W3C.

Captions, or subtitles for the deaf and hard of hearing, are a text version of all the speech and sound information of the video. They are synchronized with the audio and played at the same time as the video.
In contrast to foreign language subtitles, captions assume the viewer can’t hear any speech or audio from the video.

Who is this helping?

Captions are important for people who are deaf or hard of hearing. They're also very important to people who have difficulty processing auditory information. Non-native speakers of the spoken language of the video may also find captions helpful.

What does a captions file look like?

Dailymotion accepts captions in SRT format.

Below is a partial SRT file for the open source movie Cosmos Laundromat:

1
00:01:43,000 --> 00:01:52,000
[panting] 

2
00:01:52,000 --> 00:02:06,000 
[gasping]

3
00:02:09,000 --> 00:02:17,000
[grunting]

4
00:02:20,000 --> 00:02:21,300
Excuse me?

5
00:02:21,800 --> 00:02:23,000
Excuse me, sir?

6
00:02:24,000 --> 00:02:25,500
Excuse me?

7
00:02:27,000 --> 00:02:29,000
Oh, come on.

8
00:02:30,000 --> 00:02:32,000
Do you have a moment, sir?

9
00:02:32,000 --> 00:02:37,050
I'm kind of in the middle of something here.
Yes? Thank you.

10
00:02:37,050 --> 00:02:38,950
I've come a long way for you, Franck.

How to create captions?

For channels in English or French with at least 100 views, Dailymotion uses AI to automatically generate captions. These are a great starting point, but the quality is largely dependent on the audio quality of the video.

To ensure the highest quality, captions in SRT format created by professional captioning service providers are best. AI-powered speech-to-text captions can be used as a starting point, but will need human editing to ensure they make sense.

Where to upload captions?

Captions can be added directly from the Dailymotion Studio via the page Video details > Subtitles. See more details.

Captions automatically generated by Dailymotion don’t require any action on your part.

Relevant WCAG criteria

• 1.2.2 Captions (Prerecorded) – level A
• 1.2.8 Media Alternative (Prerecorded) – level AAA

See more information about captions from the W3C.

Captions for live streams are similar to captions for pre-recorded videos, but are shown word-by-word as transcription is done, and may have some lag with the audio due to the live nature. Live captions are usually done by real-time captioning providers, as the event takes place.

Who is this helping?

Live captions are important for the same people who need captions on pre-recorded videos. People who are deaf or hard of hearing, people who struggle with audio processing, and speakers of foreign languages.

How to create live captions?

If you require live captions, you will need to partner with a professional live captioning service.

Where to put live captions?

You can embed or add a link to the live captions provided by your chosen live captioning service on the page where the Player is embedded.

Relevant WCAG criteria

• 1.2.4 Captions (Live) – level AA
• 1.2.9 Audio-only (Live) – level AAA

Audio descriptions are spoken explanations of any visual information needed to understand the content, including images in the video.

Who is this helping?

Audio descriptions are important for people who are blind or with vision impairments.

What does audio description sound like?

Audio descriptions are usually spoken during pauses in dialog and speech, and describe what is happening on screen. Some audio descriptions are narrated by humans, others by synthetic voices.

You can see here an example of an audio description made by W3C.

How to create audio descriptions?

You will need to partner with a professional audio descriptions service provider.

Alternatively, you could write your own descriptions and record an audio track that you can add to your video in post-production.

Where to upload audio descriptions?

You can upload your new video with audio descriptions in the Dailymotion Studio, just like any other video. See more details.

Then, on your web page that has the primary video embedded, you can place a link to the version with audio descriptions.

Relevant WCAG criteria

• 1.2.3 Audio Description or Media Alternative (Prerecorded) – level A
• 1.2.5 Audio Description (Prerecorded) – level AA
• 1.2.7 Extended Audio Description (Prerecorded) – level AAA
• 1.2.8 Media Alternative (Prerecorded) – level AAA

See more information about audio descriptions from the W3C.

Sign languages use gestures, expressions, and body positions to convey meaning. There are many different sign languages across regions and countries, and they are not direct translations of spoken/written languages.

Who is this helping?

Many people who are deaf have sign language as their native language. Reading captions in a written language can be difficult since it is often a second language.

Note: not everyone who is deaf knows sign language, especially those who lost their hearing later in life.

How to incorporate sign language interpretation

You will need to partner with a professional sign language interpretation service provider.

Where to upload sign language interpretation

The simplest solution is to embed the sign language interpretation in the main video before uploading it, so all users will see sign language in the video.

You may prefer to upload a version of the video without, and another version with sign language interpretation. In this case, you can place a link to the sign language version below the Player.

Relevant WCAG criteria

• 1.2.6 Sign Language (Prerecorded) – level AAA

See more information about sign language from the W3C.