This is an archived snapshot of W3C's public bugzilla bug tracker, decommissioned in April 2019. Please see the home page for more details.

Bug 28269 - [webvtt] 6.2.1 line heights [I18N-ISSUE-436]
Summary: [webvtt] 6.2.1 line heights [I18N-ISSUE-436]
Status: VERIFIED WORKSFORME
Alias: None
Product: TextTracks CG
Classification: Unclassified
Component: WebVTT (show other bugs)
Version: unspecified
Hardware: PC All
: P2 normal
Target Milestone: ---
Assignee: This bug has no owner yet - up for the taking
QA Contact: Web Media Text Tracks CG
URL:
Whiteboard: widereview
Keywords: changeDeclined, decided
Depends on:
Blocks:
 
Reported: 2015-03-22 00:21 UTC by Silvia Pfeiffer
Modified: 2016-10-11 18:59 UTC (History)
5 users (show)

See Also:


Attachments

Description Silvia Pfeiffer 2015-03-22 00:21:31 UTC
Feedback by Addison Phillips from W3C I18N group:
http://lists.w3.org/Archives/Public/public-tt/2015Mar/0068.html

I18N comment: https://www.w3.org/International/track/issues/436

6.2.1 Processing model
http://www.w3.org/TR/2014/WD-webvtt1-20141111/#h4_processing-model

"Let lineHeight be '5.33vh' ('vh' is a CSS unit) [CSSVALUES] and regionHeight be the text track region lines."

It wasn't clear whether this sets the line-height for cue content to be a fixed height, or whether it's possible to adapt that height for scripts such as Tibetan, Thai or Arabic, which require far more vertical line height than, say, Latin text.
Comment 1 Philip J├Ągenstedt 2015-03-23 04:17:29 UTC
The default line height can be overridden by CSS, using ::cue { line-height: 10vh } or similar.

(Note that the vh unit doesn't actually work with WebVTT in any implementation AFAIK, so maybe px in the real world.)

Resolving this as WORKSFORME, please reopen if I've misunderstood the problem.
Comment 2 David Singer 2016-10-11 18:33:08 UTC
Note that for many international cases, you really need to have the ability to associate CSS. Is it clear whether VTT user-agents have to have a CSS implementation or merely parse style blocks?
Comment 3 Silvia Pfeiffer 2016-10-11 18:39:41 UTC
Addison, could you provide feedback on this bug and if you're ok with the resolution? Thanks!
Comment 4 Addison Phillips 2016-10-11 18:58:33 UTC
I think this works for me.