[whatwg] <source> media attribute behavior, static or dynamic ?

[Simon Pieters]

On Fri, 11 May 2012 11:54:19 +0200, Philip Jägenstedt <philipj at opera.com>  
wrote:

> On Thu, 10 May 2012 23:03:15 +0200, Paul Adenot  
> <padenot+whatwg at mozilla.com> wrote:
>
>> Currently implementing the media attribute of the source element in  
>> Gecko, we are unsure about what the specification requires us to do  
>> there.
>
> Hixie has already replied, I just want to note that this is exactly what  
> has been implemented in Opera -- the media attribute is only considered  
> at the point in the resource selection algorithm that the spec requires.

I'm still a bit skeptical about the utility of <media source>. Maybe it  
should be dropped from the spec.

It is not appropriate for choosing between low resolution and high  
resolution, because the environment can change (e.g. the user might  
fullscreen the video after it has begun loading, and want high  
resolution). Also, bandwidth is not available in MQ, but even if it was,  
the user agent is in a better position to determine what is appropriate  
than the author.

It would be better to have a solution where the user agent is informed  
about which streams are available and what properties they have, and let  
the user and user agent switch streams at will. Maybe this should happen  
on the network layer, keeping the same selected <source> URL.

-- 
Simon Pieters
Opera Software