- From: Maciej Stachowiak <mjs@apple.com>
- Date: Wed, 20 Apr 2011 12:50:21 -0700
- To: Sean Hayes <Sean.Hayes@microsoft.com>
- Cc: Eric Carlson <eric.carlson@apple.com>, Philip Jägenstedt <philipj@opera.com>, "public-html-a11y@w3.org" <public-html-a11y@w3.org>
On Apr 20, 2011, at 10:10 AM, Sean Hayes wrote: > That all makes a certain amount of sense; it would carry a little more weight if there were some language in the spec to the effect that autoplay is a request that the user agent can deny. For example, > > Rather than defining autoplay as: > " When present, the user agent (as described in the algorithm described herein) will automatically begin playback of the media resource as soon as it can do so without stopping " > Instead define it along the lines of: > " When present, the user agent (as described in the algorithm described herein) will; unless a user agent setting has been set indicating that immediate playback is allowed, move the media into a potentially playing but blocked state: http://www.whatwg.org/specs/web-apps/current-work/complete/video.html#blocked-media-element which is waiting for user interaction http://www.whatwg.org/specs/web-apps/current-work/complete/video.html#paused-for-user-interaction " This definition has some issues: (a) Seems to presume that no-autoplay is the default setting; this will probably not be the case. (b) Doesn't define what happens if immediate playback *is* allowed. Regards, Maciej > > Sean. > > > -----Original Message----- > From: public-html-a11y-request@w3.org [mailto:public-html-a11y-request@w3.org] On Behalf Of Eric Carlson > Sent: 20 April 2011 17:25 > To: Philip Jägenstedt > Cc: public-html-a11y@w3.org > Subject: Re: [media] adding autoplay requirements to requirements doc > > > On Apr 20, 2011, at 4:11 AM, Philip Jägenstedt wrote: > >> On Wed, 20 Apr 2011 12:08:09 +0200, Silvia Pfeiffer <silviapfeiffer1@gmail.com> wrote: >> >>> On Wed, Apr 20, 2011 at 5:41 PM, Philip Jägenstedt <philipj@opera.com> wrote: >> >>>> If it's a problem that media starts playing without user consent then it's >>>> not enough to disable autoplay, as there will certainly be sites that use >>>> scripts to start playing. >>> >>> Yes, we agreed on that, too. But we didn't see a way to catch the >>> script-created autoplays in a simple and reliable way. >> >> The browser inevitably has to know when a video should start playing. At that point, one could simply not play until an asynchronous confirmation has been given, similar to how pop-up blockers work. >> > The problem is knowing when to block script-initiated playback and/or ask the user for confirmation. "If play() was not called from a user gesture handler" is an easy answer, but that break playlists, scripts that call play() after a delay (eg. to let an animation run), etc. Requiring a user gesture doesn't really solve the problem anyway - someone that really wants to start playback automatically can call play() from an event handler registered on <body> like "pop-under window" scripts do to get around pop-up blockers today. > > We had this discussion at great length on the WhatWG several years ago. In his "Accessibility of HTML 5 video and audio elements" blog post [1], Bruce Lawson originally questioned the 'autoplay' attribute but after a few days updated the post to say "I'm now reluctantly accepting that autoplay should stay" because of Simon Pieters point [2] that: > > Removing the attribute will not make pages stop autoplaying video. Instead they will use > script to make videos autoplay, and then it becomes harder for the user to prevent > videos from autoplaying. (You could have a pref in the UA to disable autoplay="".) > > The 'autoplay' attribute on the HTMLMediaElement is useful because it allows a page authors to *request* automatic playback, but it allows a UA to *deny* that request if a user so desires. Why would the same not apply to a group of media elements? > > eric > > > [1] http://www.brucelawson.co.uk/2009/accessibility-of-html5-video-and-audio-elements/ > [2] http://lists.whatwg.org/htdig.cgi/whatwg-whatwg.org/2009-May/019647.html > > > > > >
Received on Wednesday, 20 April 2011 19:50:50 UTC