[whatwg] Google Feedback on the HTML5 media a11y specifications

Philip Jägenstedt philipj at opera.com
Wed Feb 16 03:51:59 PST 2011

On Wed, 16 Feb 2011 12:30:06 +0100, Silvia Pfeiffer  
<silviapfeiffer1 at gmail.com> wrote:

> On Wed, Feb 16, 2011 at 9:27 PM, timeless <timeless at gmail.com> wrote:
>> On Wed, Feb 16, 2011 at 10:23 AM, Kevin Marks <kevinmarks at gmail.com>  
>> wrote:
>>> Moving them only within the video viewport is a bug, not a feature.
>> Of note, the big tv we had in 2000 (probably purchased circa 1998) at
>> a college communal area would display captions for the PIP window
>> below the PIP. So even TV vendors were aware that they didn't need to
>> always stick captions into the box once they had reasonable
>> resolution.
>> Sadly I don't think I've ever seen any TVs which would shrink the
>> primary window just to supply space for captions. There's no reason
>> they couldn't, since they also do shrink the window to provide
>> onscreen menus or program guides.
>> I suppose part of the reason with big TVs is an assumption that the
>> audience will be at a fixed distance with or without captions, but
>> shrinking the view area for the programming would cause the preferred
>> distance to decrease. And as content providers actually do try to pick
>> areas which are mostly dead, the tradeoff of losing "live pixels" vs
>> decreasing optimal distance was not considered worth it.
>>> Classic
>>> TV required this (especially with overscan), but on modern TV's there  
>>> is
>>> often a letterbox or pillarbox are that captions should go in.
>> Indeed. I'm pretty sure I saw a DVD playes which took advantage of
>> this with a letterbox and stuck the captions below the movie in
>> January when I was in California.
> IIUC, the YouTube's captions can be moved within the whole video
> viewport which includes any letterboxing or pillarboxing if available.
> As for moving them outside - that would turn the whole web page into a
> potential drop zone for a div (or similar) coming from within a media
> element. That would probably not make that much sense. But I could
> imagine an application defining certain areas around the video - in
> particular below and above it - as drop zones for captions/subtitles
> and thus extend the on-screen space. I wonder what the browser vendors
> think about that feature.
> Cheers,
> Silvia.
>>> On a
>>> decent-sized computer screen, there is no real excuse for obscuring the
>>> video with the captions rather than putting them underneath or  
>>> alongside.
>> Yep. Well, it wouldn't be wrong for someone to write a 'Misery
>> compatibility mode' application to enable people to see how their
>> captions would look on old TVs, but I don't think that's something for
>> which primary applications should be designed.

I've had the same idea. The rendering of captions is already defined as  
being on top of another element, namely the parent <video> element.  
Technically, I don't think it would be very difficult to allow the  
captions to be rendered into some other container. I think this kind of  
feature should wait until we have implementations of the current spec,  

Philip Jägenstedt
Core Developer
Opera Software

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