RE: Padding on tt:p and tt:span elements

While what you say is true it is very inconvenient from an authoring perspective, and if the user can set the font (which is a requirement of the FCC rules), then you need the region to be able to adapt. Better to use the <p> background which does adapt naturally. You can artificially introduce the padding using spans with preserved space, however this is a pretty ugly hack. I think it makes sense to allow padding on these elements.

From: Glenn Adams [mailto:glenn@skynav.com]
Sent: 25 April 2012 17:04
To: John Birch
Cc: tai@irt.de; public-tt@w3.org
Subject: Re: Padding on tt:p and tt:span elements


On Wed, Apr 25, 2012 at 9:33 AM, John Birch <John.Birch@screensystems.tv<mailto:John.Birch@screensystems.tv>> wrote:
You hit the nail on the head. Font size at authoring time is only true if font exists at browser... Otherwise substitution means all bets are off.

not quite; you can always overestimate the size which permits containment without overflow

Best regards,
John


From: Glenn Adams [mailto:glenn@skynav.com<mailto:glenn@skynav.com>]
Sent: Wednesday, April 25, 2012 04:00 PM
To: John Birch
Cc: Andreas Tai <tai@irt.de<mailto:tai@irt.de>>; public-tt <public-tt@w3.org<mailto:public-tt@w3.org>>
Subject: Re: Padding on tt:p and tt:span elements


On Wed, Apr 25, 2012 at 5:22 AM, John Birch <John.Birch@screensystems.tv<mailto:John.Birch@screensystems.tv>> wrote:
In TTML as I understand it(as a result of derivation from xsl:fo?), there is no possible mechanism that can set the region size as a result of a calculation of the rendered text size on the display. In contrast to broadcast practises, in TTML the text is fitted inside a predefined region (or overflows / clips), rather than the region (growing) fitting the text.

it can, if the size can be determined at authoring time; but that will depend on font usage; so you are correct that if the font size is unknown, then you may have to overestimate the size, e.g., by using em or c length units
John Birch | Screen Systems | Strategic Partneships Manager
Main Line : +44 1473 831700<tel:%2B44%201473%20831700> | Ext : 270 | Direct Dial : +44 1473 834532<tel:%2B44%201473%20834532>
Mobile : +44 7919 558380<tel:%2B44%207919%20558380> | Fax : +44 1473 830078<tel:%2B44%201473%20830078>
John.Birch@screensystems.tv<mailto:John.Birch@screensystems.tv> | www.screensystems.tv<http://www.screensystems.tv> | http://twitter.com/ScreenSubtitles


SysMedia - Now part of Screen ......a fusion of expertise, a combination of World Leading Products

LAUNCHING SOON! A new single website incorporating all Screen and Sysmedia products.

Visit us at
Broadcast Asia, Block 4F3-01, UK Pavillion, Suntec Singapore, 19th - 22nd June 2012

P Before printing, think about the environment



This message may contain confidential and/or privileged information. If you are not the intended recipient you must not use, copy, disclose or take any action based on this message or any information herein. If you have received this message in error, please advise the sender immediately by reply e-mail and delete this message. Thank you for your cooperation. Screen Subtitling Systems Ltd. Registered in England No. 2596832. Registered Office: The Old Rectory, Claydon Church Lane, Claydon, Ipswich, Suffolk, IP6 0EQ
  ­­