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RE: Cell Grid Safe Area [was Re: ISSUE-163 (Cell units): Clarify use of cell units in certain properties [DFXP 1.0]]

From: Sean Hayes <Sean.Hayes@microsoft.com>
Date: Tue, 13 Mar 2012 17:45:24 +0000
To: Glenn Adams <glenn@skynav.com>, John Birch <John.Birch@screensystems.tv>
CC: Timed Text Working Group <public-tt@w3.org>
Message-ID: <E9A92BD0A4FC934EB7935470A46D1524090657F9@DB3EX14MBXC325.europe.corp.microsoft.com>
In some contexts (e.g. DECE) then they do specify it as coterminous. But that has to be up to the packaging usage, I don’t think the TTML spec can make any pronouncement here.

From: Glenn Adams [mailto:glenn@skynav.com]
Sent: 13 March 2012 17:41
To: John Birch
Cc: Timed Text Working Group
Subject: Cell Grid Safe Area [was Re: ISSUE-163 (Cell units): Clarify use of cell units in certain properties [DFXP 1.0]]


On Tue, Mar 13, 2012 at 11:30 AM, John Birch <John.Birch@screensystems.tv<mailto:John.Birch@screensystems.tv>> wrote:
Cell grid is taken from root extent, which implies that cell 0, 0 is at the top left boundary of the root extent.
Unfortunately in practise this is often undesirable as it is unlikely that you would want text placed so close to the boundary of the root extent.
Is there any padding like mechanism that would allow a ‘safe area’ to be defined around the edge of the ‘virtual grid’ created by cell resolution.

We do not define that the root container is coterminous with the visible screen. The external authoring context determines the origin of the root container. I believe we have assumed that all of the root container is within a safe area, but I agree that the spec does not specifically read on this point.
Received on Tuesday, 13 March 2012 17:46:27 UTC

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