Re: In-file style sheets for VTT, discussion

On 10/03/2015 22:14, David Singer wrote:
> WARNING WARNING:  email sent to both the Community Group and the Working Group.  You might wish to trim your response.
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> Friends, colleagues
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> VTT has been in a fairly quiet ‘implement and fix bugs and other inclarities in the spec.’ mode, but there is one feature request that came up while we are getting wide review of the spec as a result of the FPWD.
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> The question came up actually when we were first designing VTT, but we shelved it until now.  The request is to make it possible to provide styling in the VTT file.
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> At the moment, both the technical discussion (how do to it) and the process discussion (should we do it in this version or the next) are happening in the bug tracker:
>         https://www.w3.org/Bugs/Public/show_bug.cgi?id=15023
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> While I hate it when conversations happen in two or three places, I want to be sure that all members of both groups are aware of both aspects of this conversation and have a chance to make their opinions known, on the needs, on the design, on the timing, and so on.
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> Obviously comments on the bug would be welcome, but follow-ups to either the CG or WG would be fine also.  I’ll try to make sure everyone sees at least the Best Bits of any Relevant Conversation :-)
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> On the process, I am cautious about introducing a feature when we want to go to CR, but on the other hand, I don’t see any point in asking for a CR transition if the response to that request will be the statement from the community that this feature is missing.  It’s useful, envisioned for a long time, and can be done in a clean way, I think.


We may have other requests from the accessibility, I18N folks before 
going to CR. Let's wait for the wide review from the groups for which 
the TTWG has dependencies with.

For the styling in WebVTT, the major use case I see is that currently a 
WebVTT can be only styled in an HTML browser media player (the CCS style 
being declared in the HTML hosting page).
Therefore a WebVTT file can not be played styled in a none HTML Media 
player.
To allow this, adding CSS styling within WebVTT file would satisfy that 
need. Web browsers could also parse WebVTT file styling.

Also providing a CSS styling within WebVTT file resolves some 
accessibilities issues, if the users needs to change the default styling 
(bigger fonts, diffrent colors, etc...)


CSS stylings in the WebVTT file can be done as follows:

1-In the Header:

1.1- Import a CSS style sheet:
     Style:
       @import(cea608.css)
     ##

1.2- In a  CSS style declaration section:
     WEBVTT
       Style:
       ::cue(v[voice=Bob]) {color:green;}
       ::cue(c.question) {font-style:italic;}
     ##


2- Inline styling (throughout the WebVTT file not just in the header of 
a WebVTT file). Possibly even scoped for individual cues -
Note: Currently there is support per-cue styling via cue IDs (but not 
yet implemented).
     <style>  ::cue(#myid) {font-style : italic;}  </style>

Thierry


> Thanks
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> David Singer
> Manager, Software Standards, Apple Inc.
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Received on Wednesday, 11 March 2015 07:30:58 UTC