W3C home > Mailing lists > Public > public-html-media@w3.org > April 2014

Re: [MSE] F2F discussion items

From: David Singer <singer@apple.com>
Date: Tue, 29 Apr 2014 09:42:59 -0700
Cc: Paul Cotton <Paul.Cotton@microsoft.com>, "public-html-media@w3.org" <public-html-media@w3.org>
Message-id: <F8B0BD51-CC61-49F3-9645-3CA60339FD1E@apple.com>
To: Pierre-Anthony Lemieux <pal@sandflow.com>

On Apr 28, 2014, at 20:27 , Pierre-Anthony Lemieux <pal@sandflow.com> wrote:

> Hi David,
> 
> Some data points/questions below.
> 
>> Quantity:          Zero or more
> 
> Does this mean that more than one "kind" box can be associated with a
> single track? A given timed text track can serve multiple purposes,
> e.g. both SDH and subtitle, and hence be associated with multiple
> kinds.

OK.  But on the mpeg list there was exactly the opposite suggestion, that there be only one box.

> 
>> contains the track ‘kind’ as defined <<by the W3C spec //
>> section X of this spec. // whatever .>>.
> 
> Also, the 'kind' defined in HTML might not be sufficient alone to
> cover common kinds of timed text out there, e.g. 'commentary',
> 'large'/'Text for the Visually Impaired', 'easyreader', 'karaoke',
> etc…

There has to be some agreement what the kinds mean;  we can’t have random communities inventing kinds and then finding they use the same word with different meanings.  I think that the w3c needs to document them, and if you are not in the w3c’s spec/radar, you are on your own.

> 
>> Container:        User data box (‘udta’)
> 
> At least one specification (Ultraviolet) use the 'name' field of the
> 'hdlr' box to carry a comma-separated list of kinds for the timed text
> track.

That’s inappropriate, I think.  And strange.  

> 
> Thanks,
> 
> -- Pierre
> 
> On Wed, Apr 9, 2014 at 7:15 AM, David Singer <singer@apple.com> wrote:
>> 
>> On Apr 9, 2014, at 15:25 , Paul Cotton <Paul.Cotton@microsoft.com> wrote:
>> 
>>> [MSE] Summary of "Resolving Bug 24370" thread and proposed next steps, Aaron
>>> http://lists.w3.org/Archives/Public/public-html-media/2014Apr/0043.html
>>> 
>> 
>> 
>> I am checking with the MP4 experts at MPEG, but my inclination is that the box definition belongs in the W3C spec. anyway and would be registered at the MP4RA.  Something like
>> 
>> 1.1.1.1       Definition
>> 
>> Box Type:        ‘kind’
>> Container:        User data box (‘udta’)
>> Mandatory:      No
>> Quantity:          Zero or more
>> 
>> The kind box contains the track ‘kind’ as defined <<by the W3C spec // section X of this spec. // whatever .>>.
>> 
>> 1.1.1.2       Syntax
>> 
>> aligned(8) class TrackKindBox
>>   extends FullBox(‘kind’, version = 0, 0) {
>>   string   thekind;
>> }
>> 
>> 1.1.1.3       Semantics
>> 
>> thekind is a null-terminated string in UTF-8 characters, giving a track kind as defined by <<section X of Y>>.
>> 
>> 
>> 
>> 
>> 
>> 
>> David Singer
>> Manager, Software Standards, Apple Inc.
>> 
>> 
> 

David Singer
Manager, Software Standards, Apple Inc.
Received on Tuesday, 29 April 2014 16:50:20 UTC

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