Re: Proposal from HbbTV

Oops, wrong URL:
http://www.w3.org/html/wg/drafts/html/master/embedded-content.html#htmlmediaelement

On Sun, Oct 12, 2014 at 6:26 PM, Silvia Pfeiffer
<silviapfeiffer1@gmail.com> wrote:
> On Thu, Sep 25, 2014 at 6:56 AM, Alexander Adolf
> <alexander.adolf@condition-alpha.com> wrote:
>> Dear Silvia,
>>
>> On 2014-09-24, at 22:32 , Jon Piesing <Jon.Piesing@tpvision.com> wrote:
>>
>>>> If a text track never exposes any cues, we shouldn't expose its existence to browsers. That's like saying: hey, I have some data, but I won't give it to you. Or if we apply that logic to an audio or video stream: it's like announcing that a video stream exists, but not rendering it. Such tracks are not relevant to this specification.
>>>
>>> What about text tracks that are rendered by the (native) media player and where HTML would like to be able to enable/disable them in the same way as video & audio?
>>> [...]
>>
>> Our (though unstated) assumption is that a browser in a TV set (which is what we are targeting) will be able to render subtitles and captions tracks. Hence, the following would display the video with some flavour subtitles:
>>
>> <video>
>>   <source src=’http://mycdn.de/video.mp4’ type=’video/mp4’>
>>   <track kind=’subtitles’ srclang=’de’ label=’German for the English’
>>    src=’http://mycdn.de/subtitles_de.ttml’ />
>>   <track kind=’subtitles’ srclang=’de’ label=’German for the hard of hearing’
>>    src=’http://mycdn.de/subtitles_de2.ttml’ />
>>   <track kind=’captions’ srclang=’en’
>>    src=’http://mycdn.de/subtitles_hearing_impaired.ttml’ />
>> </video>
>
> Just a note on this: this is markup for external text tracks. This is
> definitely not how in-band tracks will be exposed.
>
> What you probably mean instead is that these inband tracks will be
> part of the media element's list of textTracks just like such external
> text tracks:
>
> interface HTMLMediaElement : HTMLElement {
> ...
>   readonly attribute TextTrackList textTracks;
> ...
> }
>
> see http://www.w3.org/html/wg/drafts/html/master/dom.html#htmlelement .
>
> For external tracks like the above you're going to have to define a
> parser that is part of Web browsers and thus exposing TextTrackCues
> will not be the difficult part.
>
> Best Regards,
> Silvia.
>
>
>> At the JS level, selecting the track would have the side effect of the platform rendering it; just like for video and audio. In the above example, the script's choice of text track would likely be based on the user's impairment type and language preferences.
>>
>> In such an environment, we thought that selecting/unselecting a text track would be sufficient, and couldn't think of anything interesting that could be done with a cue.
>>
>> Cheers,
>>
>>   --alexander

Received on Sunday, 12 October 2014 08:14:37 UTC