github.com/paypal/accessible-html5-video-player

Accessible HTML5 Video Player

What is it?

A lightweight HTML5 video player which includes support for captions and screen reader accessibility. For details, read the blog post Introducing an Accessible HTML5 Video Player on the PayPal Engineering blog (updated link). Also see 7 Lessons from Developing an Accessible HTML 5 Video Player.

Features

• Provides an HTML5 video player with custom controls.
• Supports captions; simply denote a VTT caption file using the standard HTML5 video syntax.
• Uses native HTML5 form controls for volume (range input) and progress indication (progress element).
• Accessible to keyboard-only users and screen reader users.
• Option provided to set captions on or off by default (upon loading).
• Option provided to set number of seconds by which to rewind and forward.
• Text strings for the controls are externalized to allow for internationalization (fall 2015).
• No dependencies. Written in "vanilla" JavaScript.
• When JavaScript is unavailable, the browser's native controls are used.
• React support

Implementation

CSS and Image

Insert the CSS in the Head of your HTML document. You'll also need to upload the sprite image (or use your own) and adjust the path in the CSS file.

<link rel="stylesheet" href="/css/px-video.css" />

HTML

Insert the HTML5 video markup in the Body of your HTML document. Replace the video, poster, and caption URLs. Modify the sizes of video and fallback image as needed.

<div class="px-video-container" id="myvid">
    <div class="px-video-img-captions-container">
        <div class="px-video-captions hide" aria-hidden="true"></div>
        <video width="640" height="360" poster="media/foo.jpg" controls>
            <source src="foo.mp4" type="video/mp4" />
            <source src="foo.webm" type="video/webm" />
            <track kind="captions" label="English captions" src="media/foo.vtt" srclang="en" default />
            <div>
                <a href="foo.mp4">
                    <img src="media/foo.jpg" width="640" height="360" alt="download video" />
                </a>
            </div>
        </video>
    </div>
    <div class="px-video-controls"></div>
</div>

JavaScript

Insert two JavaScript files right before the closing Body element of your HTML document. Add a Script element to initialize the video. Options are passed in JSON format. The options are:

option	description	dataType		default
videoId	the value of the ID of the widget container	string	required
captionsOnDefault	denotes whether to show or hide caption upon loading	boolean	optional	true
seekInterval	the number of seconds to rewind and fast forward	number	optional	10
videoTitle	short title of video; used for aria-label attribute on Play button to clarify to screen reader user what will be played	string	optional	Play
debug	turn console logs on or off	boolean	optional	false

<script src="js/strings.js"></script>
<script src="js/px-video.js"></script>
<script>
// Initialize
new InitPxVideo({
    "videoId": "myvid",
    "captionsOnDefault": true,
    "seekInterval": 20,
    "videoTitle": "clips of stand-up comedy",
    "debug": true
});
</script>

View Demo

React Version

The React version has been designed to be integrated into your react codebase easily. The video React component is named PXvideo and has the below API:

<PXVideo
    sources={[
    'https://www.paypalobjects.com/webstatic/mktg/videos/PayPal_AustinSMB_baseline.mp4',
    'https://www.paypalobjects.com/webstatic/mktg/videos/PayPal_AustinSMB_baseline.webm'
  ]}
  caption={{
    label: 'English captions',
    source: 'media/captions_PayPal_Austin_en.vtt',
    lang: 'EN',
    default: true
  }}
  poster="media/poster_PayPal_Austin2.jpg"
  width="640"
  height="360"
  controls={true}
  id="myvid"
  fallback={true}
  seekInterval={20}
  debug={true}
/>

A demo could be reached at: View Demo

Development

npm install // install dependencies
npm run react // transpile .jsx into valid .js using Babel

Feedback and Contributions

If you experience any errors or if you have ideas for improvement, please feel free to open an issue or send a pull request.

You can also follow and contact the PayPal Accessibility team on Twitter: @PayPalInclusive No longer exists.

Authors/Maintainer

• Dennis Lembree (primary developer) https://github.com/weboverhauls || @dennisl
• Victor Tsaran (consultation and testing) || https://github.com/vick08 || @vick08
• Jason Gabriele (consultation)
• Tim Resudek (design)
• Nawaz Khan (developer) https://github.com/mpnkhan
• Hozefa Jodiawalla (developer) https://github.com/hozefaj || @hozefaj

Browser Support

• Chrome: full support.
• Safari: full support.
• Firefox: full support.
• Internet Explorer 10, 11: full support.
• Internet Explorer 9: native video player used (aesthetic choice since HTML5 range input and progress element are not supported).
• Internet Explorer 8: renders fallback content of video element (in the demo, this is an image linked to the video file).
• Smartphones and tablets: controls and captions are not customized as both are natively supported in latest versions.

Limitations and Known Issues

• Currently, only one caption file per video is supported.
• Only VTT caption files are supported (not SRT nor TTML). VTT cue settings are not supported but inline styles function (see first few lines of example).
• The controls have a minimum width of 360px.

Related Resources

• HTML5 Video Events and API - by W3C
• Adding captions and subtitles to HTML5 video - by MDN
• Simple SubRip to WebVTT converter - tool to convert SRT captions to WebVTT
• Able Player - accessible cross-browser media player by Terrill Thompson

Projects influenced by the PayPal Accessible HTML5 Video Player

• Universal Video Player - by Ind.ie, @LauraKalbag
• Plyr - by @sam_potts, @selz

Copyright and License

Copyright 2019, PayPal under the BSD license.