Note: Last updated July 7th, 2017 to include the Web Experience Project media player and captioning legal requirements from the USA. If you have a suggested link leave a comment and I’ll add it.
Below are a few resources around media player accessibility. With so many of us embedding multimedia content in our sites and apps it’s key that we think about not just the accessibility of the player but also alternative formats, the user journey to the player and onward journeys from the player.
If you have a suggested link let me know.
Below are a collection of formal guidelines from W3C.
Web Content Accessibility Guidelines version 2, Level A and AA:
- 1.2.2 Captions (Prerecorded): Captions are provided for all prerecorded audio content in synchronized media, except when the media is a media alternative for text and is clearly labeled as such. (Level A)
- 1.2.4 Captions (Live): Captions are provided for all live audio content in synchronized media. (Level AA)
- 1.2.8 Media Alternative (Prerecorded): An alternative for time-based media is provided for all prerecorded synchronized media and for all prerecorded video-only media. (Level AAA)
- 1.4.8 Visual Presentation: For the visual presentation of blocks of text, a mechanism is available to achieve the following: (Level AAA)
- Media Accessibility User Requirements – This document presents the accessibility requirements users with disabilities have with respect to audio and video on the web.
- WebVTT: The Web Video Text Tracks Format – WebVTT files provide captions or subtitles for video content, and also text video descriptions [MAUR], chapters for content navigation, and more generally any form of metadata that is time-aligned with audio or video content.
- Flash 17 – Providing keyboard access to Flash objects – Techniques for Flash
- Multimedia accessibility FAQ – W3C’s internal multimedia accessibility policy is in place to ensure that W3C’s work is accessible to all, including people with disabilities who cannot hear audio or see video, and to ensure that it meets W3C’s own standards
- User Agent Accessibility Guidelines – UAAG 2.0 guides developers in designing user agents that make the web more accessible to people with disabilities. User agents include browsers, media players and applications that render web content. Specifically the following guidelines:
- Timed Text Markup Language (TTML1) – can be used for subtitles and captions and support a rich set of styling and position information.
- Profiles for Internet Media Subtitles and Captions (IMSC 1: TTML) specifies two profiles of TTML, one for text based subtitles, the other for image based ones. This specification is being referenced by MPEG in its Common Media Application Framework (CMAF) work, and for that reason Apple recently announced support for it in their upcoming operating system releases due in the autumn.
Below are a list of standards and guidelines outside of W3C that relate to multimedia accessibility.
- 21st Century Communications and Video Accessibility Act – Title II Communications Access
- Multimedia and video programming – Web Accessibility Best Practices
- Specification for an accessible media player by Coolfields
- Video Accessibility Principles – Oz Wiki Accessibility
- Video Accessibility – Mozilla wiki
- European Broadcasting Union Subtitling – the European Broadcasting Union has a suite of specifications covering all parts of the publication and distribution chain, all based on TTML. They include specifications for streaming live subtitles, file format details for prepared subtitles, conversion from the legacy STL format, and distribution as EBU-TT-D (very closely related to IMSC 1 Text profile).
Accessible Media players
Disclaimer: I have not tested all the players below so they are self-proclaimed accessible players.
- American Federation for the Blind Media Player
- AblePlayer – Terril Thompson
- Acorn Media Player
- AlphaGov Accessible Media Player – a forked version of Nomensa’s accessible video player on Github
- AMI player – from Accessible Media INC
- Brightcove accessible video player
- BBC Standard Media Player (SMP) – used on iPlayer, News, Sport, Live etc, including the SMP help page
- Accessible JW Player and JW Player which claims WCAG 2.0 compliance
- E-Standards accessible HTML5 video player – Created by e-Works this player recently got won a captioning award
- Nomensa’s accessible video player (Github)
- Accessible HTML5 Video Player – by PayPal
- The Workshop accessible media player
- Accessible YouTube player – Vision Australia
- Web Experience Toolkit Multimedia Player
This section covers captions / subtitles, sign language and audio description.
- Described video best practices – AMI Accessible Media Canada
- eAccess Guide to audio description
- Best Practices for Post Production and Emerging Forms of Post Production – Accessible Media Inc
- Pictures of You with audio description – example of a player with AD on/off button
- YouDescribe – audio description tool for YouTube videos
- What is Integrated Described video (IDV)
Captioning / Subtitles
- BBC Subtitle Guidelines – BBC
- Guidance on standards for subtitling – OFCOM
- Captioning and Audio Description Tips
- Captioning FAQ – from WGBH
- How to load captions to YouTube videos
- Amara – captioning service
- Dotsub – captioning service
- Android Developer Guidelines for captions – number 6 ‘Video playback and captioning’ for supporting user preferences on how closed captions render
- Android Developer Guidelines for captions on Kitkat – See ‘System-wide settings for closed captioning’
- Android Developer Guidelines Android 4.4 APIs – see ‘Closed Captions’
- iOS Media Accessibility Function Reference – details on supporting user preferences on how closed captions render
- ROI analysis and SEO benefits of closed captioning – 3 Play Media
Captioning legal requirements from the USA
Below is a list of standards and guidelines outside of WCAG that I believe relate to the legal requirement for captioning in the USA:. The following list is evolving:
- Closed Captioning Quality Report and Order, Declaratory Ruling, FNPRM
- FCC Captioning of Internet Video Programming
- Preamble to Section 508 Standards Subpart C
- Section 508, 1194.24 Video and Multimedia products
- Comparison of Browsers on HTML5 Video Accessibility: 2015 Update – Terrill Thompson
- A comparison of HTML5 video players
Blogs and articles
- I Heart Subtitles – by Dawn Jones
- A more accessible HTML5 media player – Dev Opera
- Creating and accessible media player in Flash – BBC
- Standard Media Player accessibility – BBC
- Web Accessibility requirements for media players – Researchgate
- Practical cross-browser accessible media player – MSDN
- Media Player accessibility – various posts by Terrill Thompson
- Comparison of features in accessible HTML5 video players
- Media Player accessibility – AccessIQ
- Audio Description or Media Alternative for Synchronised Multimedia – WebAccessibility.com
- The great video game subtitle debate: On or Off – at the time of reading 79% of Tomb Raider gamers said they leave subtitles on
Disclaimer: I was not sidetracked into watching any TV in researching this blog post. Not one bit.