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Re: Media elements may never load, may load the wrong source, etc

From: Philip Jägenstedt <philipj@opera.com>
Date: Thu, 09 Apr 2009 17:27:37 +0200
To: Philip Jägenstedt <philipj@opera.com>, public-html@w3.org
Message-ID: <op.ur4k8bbxatwj1d@sisko.linkoping.osa>
On Thu, 09 Apr 2009 10:49:33 +0200, Philip Jägenstedt <philipj@opera.com>  
wrote:

> Some feedback on the big batch of changes to media elements made in  
> March.
>
> 1. may never load
>
> Previously there were many conditions for when to implicitly invoke the  
> load() method, e.g. when a media element was inserted into a document.  
> This was all replaced by the resource selection algorithm, but as far as  
> I can see that algorithm is only invoked by an explicit load() and in  
> the Audio(src) constructor.
>
> In other words, there's nothing to cause e.g. <video autobuffer  
> autoplay> to either begin buffering or playing unless a script  
> explicitly calls load() or play() on it.
>
> For simplicity I would prefer that the resource selection algorithm be  
> started for any media element, regardless of whether it has any  
> src/source, is in a document or any other conditions. This makes all of  
> the below equivalent:
>
> <audio src="foo">
>
> a=new Audio("foo");
>
> a=new Audio();
> a.src="foo";
>
> a=document.createElement("audio");
> a.src="foo";
>
> This behavior isn't incredibly important in itself, but it removes the  
> need for special cases in the Audio constructor or elsewhere. Ignoring  
> whether or not the media element is in a document when invoking the  
> resource selection/fetch algorithm makes sense for preloading, etc so I  
> don't think we should reintroduce that.

My apologies, a text searching bug in Opera caused me to miss the  
following:

If a media element whose networkState has the value NETWORK_EMPTY is  
inserted into a document, the user agent must invoke the media element's  
resource selection algorithm.

In other words, my above complaint is invalid and I don't suggest any  
changes in how the resource selection algorithm is invoked. The examples  
given above will behave differently, but that's not a big problem as far  
as I can see.

Hope I didn't overlook something with the other two points...

-- 
Philip Jägenstedt
Opera Software
Received on Thursday, 9 April 2009 15:27:36 GMT

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