Re: comments on spatial media fragment (a broadcaster's perspective)

On Thu, Nov 3, 2011 at 3:52 AM, Philip Jägenstedt <philipj@opera.com> wrote:
> On Wed, 02 Nov 2011 17:11:46 +0100, Duncan Rowden <Duncan.Rowden@bbc.co.uk>
> wrote:
>
>> 2)      I couldn't see anywhere in your document anything regarding
>> switching between spatial regions. From a broadcaster / content provider
>> perspective it would be highly desirable if the switching mechanism
>> didn't affect the video pipeline (i.e. no delays to video playback).
>> Could this possibly be added in?
>
> Assuming we are still talking about <video>, the only way to change the
> fragment is by setting the src attribute, which invokes the resource
> selection algorithm and causes all state to be lost. This is not something
> the MF spec can do anything about, it'd have to be a change in HTML.
>
> If scripts need to be involved anyway, maybe slicing the video by modifying
> CSS would be an alternative?

I agree. For this particular use case I would suggest using JavaScript
and CSS for now, because it will give you the right results without
overhead.

It could be implemented natively in browsers for spatial media
fragment URIs in such a way that browsers will not invoking a reload
when just the hash changes for a URI, but only the display is changed.
However, this is not something that browsers have implemented right
now for video. The only situation where browsers do exactly this is
for HTML pages when you change the hash value - the HTML page is not
reloaded, but only the hash change is resolved locally. This is
because that hooks into the history interface. I am not sure whether
we can get this into elements (e.g. images and videos).

Cheers,
Silvia.

Received on Wednesday, 2 November 2011 22:08:55 UTC