[whatwg] Synchronized play/seek of multiple <audio> elements?

Charles McCathieNevile chaals at opera.com
Thu Feb 26 07:24:04 PST 2009

On Thu, 19 Feb 2009 01:43:22 -0000, David Singer <singer at apple.com> wrote:

> At 10:20  +0000 18/02/09, Ian Hickson wrote:
>> On Wed, 18 Feb 2009, Emil Tin wrote:
>>>  However, I've been unable to find any information on how to trigger
>>>  several audio files in a synchronized manner.
>>>  Does the html 5 specification provide any way to to this?
>> Not currently.
> Yes. We felt it would be a major complication to the spec., and wanted  
> to keep things simple for the first iteration.

A problem arises for accessibility, when you extend this to video and need  
to synchronise captions / subtitles / audio descriptions, if they are not  
included in the original resource.

There are various use cases for having the resource be stand-alone, and  
also for compound resources that HTML5 can pull together. At the FOMS  
discussion of accessibility, I believe the end result was an understanding  
(no formal resolution) that both approaches needed to be supported.

This could be done in HTML5 by recommending something like a SMIL resource  
to deal with the second use case, shifting the implementation requirement  
to support (at least some of) SMIL for playing video. Or by adding some  
simple timing stuff to HTML itself, although that makes for backwards  
incompatibility even with current browsers having native video support. Or  
using SVG and pegging its timeline to the enclosing video, or ...

These are not ready-made solutions, they are thoughts about possible  



Charles McCathieNevile  Opera Software, Standards Group
     je parle français -- hablo español -- jeg lærer norsk
http://my.opera.com/chaals       Try Opera: http://www.opera.com

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