Re: Inband styling (was Re: Evidence of 'Wide Review' needed for VTT)

On 21/10/2015 14:00, "singer@apple.com on behalf of David Singer"
<singer@apple.com> wrote:

>
>> On Oct 21, 2015, at 14:36 , Philip Jägenstedt <philipj@opera.com> wrote:
>> 
>> On Wed, Oct 21, 2015 at 2:17 PM, David Singer <singer@apple.com> wrote:
>>> 
>>> Yes, the static transcoding case is easier.  It is, alas, not the only
>>>one.
>> 
>> What we are talking about is the conformance requirements of
>> standalone WebVTT files and what the WebVTT parser will do if
>> encountering style blocks after a cue.
>
>No, I think I must disagree.  Is such a restriction written anywhere
>(that files cannot be incrementally produced)?  You might argue that the
>incremental production case isn’t specifically included either, but I
>think we live in a world with more english than german rules :-)
><https://en.wikipedia.org/wiki/Everything_which_is_not_forbidden_is_allowe

>d#National_traditions>
>
>> In this context, static
>> resources really is all that exists, as live captioning with
>> <track>+WebVTT [1] hasn't been spec'd. If there are other contexts
>> that use the WebVTT syntax and parser in a streaming mode, then that
>> would be interesting to know. AFAICT, it would only be a situation
>> like that where there could be a problem, and if it's only a
>> hypothetical at this point I don't think that should affect how WebVTT
>> works in the context of <track>.
>
>No, it’s not hypothetical.  DASH/MP4/VTT relies on this, and it was (and
>is) seen as a core advantage of VTT over TTML.

How curious. Live streaming with DASH/MP4/TTML works splendidly - there
were lots of implementations on show at IBC in September, of both coders
and presentation systems, based on EBU-TT-D, which is the profile of TTML
that is specified for HbbTV 2.0 and the DVB DASH profile. The dash.js
player is one. Samsung had a prototype television that was decoding and
presenting this format too - I'm pretty sure that there are others in the
works. The BBC has prototyped an implementation built on gstreamer that
works well also.

What advantage was identified with VTT in this scenario?

>
>David Singer
>Manager, Software Standards, Apple Inc.
>
>

Received on Wednesday, 21 October 2015 13:38:13 UTC