Re: URI for HTML5 Kind values in MP4 files

Hi Nigel,

Le 27/06/2016 à 17:34, Nigel Megitt a écrit :
> Hi Cyril,
>
> I think this sounds good because the current set of kind values is very
> limited and not generally useful; conversely a fixed limited set does
> allow user agents to be written that offer kind-based functionality more
> easily.
>
> The only meaningful functionality I am aware of is whether to present the
> track or not, which cannot be derived from a schemeURI.
>
> Therefore right now I'm in favour of your proposal, with the addition that
> there should be a boolean companion value that tells the UA whether to
> present the track by default or not.
Apparently, HTML has decided to use another (strange) signaling: 
"about:html-kind", see 
https://github.com/w3c/html/issues/557#issuecomment-244283057

Cyril
>
> Kind regards,
>
> Nigel
>
>
> On 21/06/2016 16:19, "Cyril Concolato"
> <cyril.concolato@telecom-paristech.fr> wrote:
>
>> Hi,
>>
>> The ISOBMFF introduced the 'kind' box (see ISO/IEC 14496-12:2015,
>> available here
>> http://standards.iso.org/ittf/PubliclyAvailableStandards/c068960_ISO_IEC_1
>> 4496-12_2015.zip).
>> This 'kind' box can be used to store the 'kind' of a track as defined by
>> different standards. For instance, it could be used to store DASH
>> Descriptors associated with a track or the HTML 5 'kind' values for
>> audio/video/text tracks. In order to tell from a kind value, which
>> standard is referred to, the "kind" box stores a pair: schemeUri / value
>> (similar to DASH descriptors).
>>
>> This email is to propose that the HTML standard defines a schemeUri for
>> its kind values. I'm sending this request to this list first, as I think
>> this probably should be reviewed in the context of the sourcing spec
>> first. I propose to define the following schemeURI "urn:w3c:html5:kind".
>>
>> I have made a set of mp4 files with the different values available here:
>> http://download.tsi.telecom-paristech.fr/gpac/mp4box.js/mp4/html5-kind/.
>> I have also made a test player that parses these mp4 files based on
>> MP4Box.js and that creates MSE SourceBuffers, setting the Track Defaults
>> with the values from the mp4 file. The demo is here:
>> http://download.tsi.telecom-paristech.fr/gpac/mp4box.js/. Check the
>> "HTML 5 Track Kind" examples. Unfortunately, it is not fully working in
>> browsers as no current browser supports the Track Defaults feature, yet.
>> I hear also that the feature itself is marked at risk in MSE, which
>> would be a problem I think.
>>
>> Comments, questions are welcome.
>>
>> Regards,
>>
>> -- 
>> Cyril Concolato
>> Multimedia Group / Telecom ParisTech
>> http://concolato.wp.mines-telecom.fr/
>> @cconcolato
>>
>>


-- 
Cyril Concolato
Multimedia Group / Telecom ParisTech
http://concolato.wp.mines-telecom.fr/
@cconcolato

Received on Friday, 2 September 2016 07:44:20 UTC