html5 and accessibility sitting in a tree
DESCRIPTION
21 September 2011 presentation to Accessibility London (#a11yldn) unconference on HTML5 and accessibility by Bruce Lawson of Opera.TRANSCRIPT
HTML5 and a11ySitting in a treeBruce Lawson
Biscuit and Chica photograph by Brittany Shaw. All rights reserved. Used with permission
30 new elements 30 new elements
Top 20 class names1. footer 11. button
2. menu 12. main
3. style1 13. style3
4. msonormal 14. small
5. text 15. nav
6. content 16. clear
7. title 17. search
8. style2 18. style4
9. header 19. logo
10. copyright 20. body
http://devfiles.myopera.com/articles/572/classlist-url.htm
Top 20 id names1. footer 11. search
2. content 12. nav
3. header 13. wrapper
4. logo 14. top
5. container 15. table2
6. main 16. layer2
7. table1 17. sidebar
8. menu 18. image1
9. layer1 19. banner
10. autonumber1 20. navigation
http://devfiles.myopera.com/articles/572/idlist-url.htm
<content> ?
HTML5 formsstandardise commonly-used
rich form elements – without JavaScript
built-in validation(of course you should still validate on the server)
<input type=email><input type=url required>
<input type=range min=10 max=100><input type=date min=2010-01-01 max=2010-12-31>
<input pattern="[0-9][A-Z]{3}" placeholder="9AAA">http://people.opera.com/brucel/demo/html5-forms-demo.html
<video> and <audio>
Anne van Kesteren annevk at opera.comWed Feb 28 05:47:56 PST 2007
Hi,Opera has some internal expiremental builds with an implementation of a <video> element. The element exposes a simple API (for the moment) much like the Audio() object: play() pause() Stop()
The idea is that it works like <object> except that it has special <video> semantics much like <img> has image semantics. In markup you could prolly use it as follows:
<figure> <video src=news-snippet.ogg> ... </video> <legend>HTML5 in BBC News</legend> </figure>
I attached a proposal for the element and as you can see there are still some open issues. The element and its API are of course open for debate. We're not enforcing this upon the world ;-)
Cheers,http://lists.whatwg.org/pipermail/whatwg-whatwg.org/2007-February/009702.html
<object width="425" height="344"><param name="movie"
value="http://www.example.com/v/9sEI1AUFJKw&hl=en&fs=1&"></param>
<param name="allowFullScreen" value="true"></param>
<param name="allowscriptaccess" value="always"></param>
<embed src="http://www.example.com/v/9sEI1AUFJKw&hl=en&fs=1&" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="425" height="344"></embed></object>
<video src=pudding.webm controls autoplay poster=poster.jpg width=320 height=240> <a href=video.webm>Download movie</a></video>
<audio src=jedward.ogg controls autoplay> <a href=jedward.ogg>Download horrid pap</a></audio>
<video src=pudding.webm loop>
<audio src=jedward.ogg preload><audio src=jedward.ogg preload=auto><audio src=jedward.ogg preload=none><audio src=jedward.ogg preload=metadata>
powerful (simple) API
controlling <video> with JavaScript
var v = document.getElementByTagName('video')[0];
v.play();v.pause();v.volume = … ;v.currentTime = … ;…
events fired by <video>var v = document.getElementById('player');v.addEventListener('loadeddata', function() { … }, true)v.addEventListener('play', function() { … }, true)v.addEventListener('pause', function() { … }, true)v.addEventListener('timeupdate', function() { … }, true)v.addEventListener('ended', function() { … }, true)…
video as native object...why is it important?
● keyboard accessibility built-in● “play nice” with rest of the page● Simple API for controls
video formats
webM Ogg/ Theora mp4/ h264
Opera yes yes
Chrome yes yes Nope (Chrome.soon)
Firefox Yes (FF4) yes
Safari yes
IE9 Yes (if installed) yes
audio formats
mp3 Ogg/ Vobis wav
Opera yes yes
Chrome yes yes
Firefox yes yes
Safari yes yes
IE9 yes no
Giving everybody video
<video controls autoplay poster=… width=… height=…><source src=pudding.mp4 type=video/mp4><source src=pudding.webm type=video/webm><source src=pudding.ogv type=video/ogg><!-- fallback content -->
</video>
<video controls poster="…" width="…" height="…"><source src="movie.mp4" type="video/mp4" /><source src="movie.webm" type="video/webm" /><source src="movie.ogv" type="video/ogg" /><object width="…" height="…" type="application/x-
shockwave-flash" data="player.swf"><param name="movie" value="player.swf" /><param name="flashvars" value=" … file=movie.mp4" /><!-- fallback content -->
</object></video>
still include fallback for old browsershttp://camendesign.com/code/video_for_everybody
Help
● archive.org converts and hosts creative-commons licensed media
● vid.ly has a free conversion/ hosting service (max 1GB source file) see vid.ly/5u4h3e
● Miro video converter is a drag and drop GUI skin on FFMPEG
Full-screen video● Currently, WebkitEnterFullscreen();● May 11, WebKit announced it's implementing Gecko API https://wiki.mozilla.org/Gecko:FullScreenAPI
● Opera likes this approach, too
<video> accessibility
WebM release does not support subtitles
http://code.google.com/p/webm/issues/detail?id=11Egg image Kacper "Kangel" Aniołek http://commons.wikimedia.org/wiki/File:Egg.jpg
WHATWG / W3C RFC will release guidance on subtitles and other overlays in HTML5 <video> in the near future. WebM intends to follow that guidance.
<track> element
<video controls poster=… width=… height=…><source src=movie.webm type=video/webm><track src=subtitles-en.vtt kind=subtitles srclang=en><track src=subtitles-de.vtt kind=subtitles srclang=de><!-- fallback content -->
</video>
http://www.whatwg.org/specs/web-apps/current-work/multipage/video.html#the-track-element
webVTT
WEBVTT FILE
101:23:45,678 --> 01:23:46,789Hello world!
201:23:48,910 --> 01:23:49,101HelloWorld!
WebVTT formatting
Supports positioning of text
Supports <b> and <i>
Colouring individual speakers
Support vertical text
Supports RTL
Supports ruby annotations
<track> polyfillhttp://www.delphiki.com/html5/playr/
Synchronising media elements@mediagroup
www.whatwg.org/specs/web-apps/current-work/multipage/video.html#synchronising-multiple-media-elements
getUserMedia API(previously known as "HTML5 <device>")
my.opera.com/core/blog/2011/03/23/webcam-orientation-preview
WebRTC is a free, open project that enables web browsers with Real-Time Communications (RTC) capabilities via
simple Javascript APIs. The WebRTC components have been optimized to best serve this purpose.
The WebRTC initiative is a project supported by Google, Mozilla and Opera.
http://sites.google.com/site/webrtc/http://www.whatwg.org/specs/web-apps/current-work/complete/video-conferencing-
and-peer-to-peer-communication.html
All rights reserved corner
Thanks Takara Tomy for permission to use Gigapudding video. Buy the pudding.
HTML5 nazi-killing Bruce on unicorn picture by Marina Lawson. Buy her Dad's book.
Thanks Brittany Shaw for permission to use her Biscuit and Chica photo. Buy a rabbit pie.
All others by me or (I believe) public domain.
