W3C home > Mailing lists > Public > public-tt@w3.org > May 2009

RE: ISSUE-101 (rollup interval): aribitrary interval for rollup needs justification [DFXP 1.0 (Editorial)]

From: Geoff Freed <geoff_freed@wgbh.org>
Date: Fri, 15 May 2009 12:53:12 -0400
To: Sean Hayes <Sean.Hayes@microsoft.com>, Timed Text Working Group WG <public-tt@w3.org>
Message-ID: <E36081A12A13F146AC32D7724B0E891219E00E8247@EXCHCCR.wgbh.org>

one more thing:  in the 708 specification (http://www.fcc.gov/Bureaus/Engineering_Technology/Notices/1999/fcc99180.txt), i found the following info:

============

  9.10.4 Scroll Rate
  
  At a minimum, decoders must support the same recommended practices for scroll rate as
  is provided for NTSC closed-captioning.
  
  9.10.5 Smooth Scrolling
  
  At a minimum, decoders must support the same recommended practices for smooth
  scrolling as is provided for NTSC closed-captioning.

============


this would mean that .433s is the minimum rate at which DTV decoders must scroll the text.  to be consistent with this, perhaps we should alter the text to include both analog and digital specs, like this:


"If the value of this attribute is rollUp, then this value is interpreted as a shorthand value equivalent to out(line,smooth) inter(0.433s).  This time interval is intended to be compatible with "Closed Caption Decoder Requirements for Analog Television," page 792 (http://edocket.access.gpo.gov/cfr_2005/octqtr/47cfr15.119.htm), and "Closed Captioning Requirements for Digital Television Receivers," Sections 9.10.4 and 9.10.5 (http://www.fcc.gov/Bureaus/Engineering_Technology/Notices/1999/fcc99180.txt)."

g.


________________________________________
From: Sean Hayes [Sean.Hayes@microsoft.com]
Sent: Friday, May 15, 2009 9:48 AM
To: Geoff Freed; Timed Text Working Group WG
Subject: RE: ISSUE-101 (rollup interval): aribitrary interval for rollup  needs justification [DFXP 1.0 (Editorial)]

Ok, although rather than 'defined by'; I'd prefer to say 'intended to be compatible with', since we are defining it and we don't want it as a normative reference.

rollup doesn't seem to be defined in EBU3264 or DVB subtitles, so unless Franz or David objects to the US centric nature of this reference, this is fine by me.

Sean Hayes
Media Accessibility Strategist
Accessibility Business Unit
Microsoft

Office:  +44 118 909 5867,
Mobile: +44 7875 091385


-----Original Message-----
From: Geoff Freed [mailto:geoff_freed@wgbh.org]
Sent: 15 May 2009 2:29 PM
To: Sean Hayes; Timed Text Working Group WG
Subject: RE: ISSUE-101 (rollup interval): aribitrary interval for rollup needs justification [DFXP 1.0 (Editorial)]


for section 8.2.7 (http://www.w3.org/TR/2009/WD-ttaf1-dfxp-20090511/#style-attribute-dynamicFlow), paragraph #5:

"If the value of this attribute is rollUp, then this value is interpreted as a shorthand value equivalent to out(line,smooth) inter(0.433s).  This time interval is defined by "Closed Caption Decoder Requirements for Analog Television," page 792 (http://edocket.access.gpo.gov/cfr_2005/octqtr/47cfr15.119.htm).

how's that?

g.

________________________________________
From: Sean Hayes [Sean.Hayes@microsoft.com]
Sent: Friday, May 15, 2009 7:04 AM
To: Geoff Freed; Timed Text Working Group WG
Subject: RE: ISSUE-101 (rollup interval): aribitrary interval for rollup  needs justification [DFXP 1.0 (Editorial)]

That would be helpful. If you can suggest wording for the spec that would be even better.

Sean Hayes
Media Accessibility Strategist
Accessibility Business Unit
Microsoft

Office:  +44 118 909 5867,
Mobile: +44 7875 091385


-----Original Message-----
From: public-tt-request@w3.org [mailto:public-tt-request@w3.org] On Behalf Of Geoff Freed
Sent: 15 May 2009 11:57 AM
To: Timed Text Working Group WG
Subject: RE: ISSUE-101 (rollup interval): aribitrary interval for rollup needs justification [DFXP 1.0 (Editorial)]


this corresponds to the speed of the scroll of 608 roll-up displays, i believe.  i can look this up if you need me to.

g.

________________________________________
From: public-tt-request@w3.org [public-tt-request@w3.org] On Behalf Of Timed Text Working Group Issue Tracker [sysbot+tracker@w3.org]
Sent: Friday, May 15, 2009 6:54 AM
To: public-tt@w3.org
Subject: ISSUE-101 (rollup interval): aribitrary interval for rollup needs justification [DFXP 1.0 (Editorial)]

ISSUE-101 (rollup interval): aribitrary interval for rollup needs justification [DFXP 1.0 (Editorial)]

http://www.w3.org/AudioVideo/TT/tracker/issues/101

Raised by: Sean Hayes
On product: DFXP 1.0 (Editorial)

In the Proposed 'rollup' shorthand. The 'inter' value of 0.433s needs some justification or explanantion
Received on Friday, 15 May 2009 16:53:55 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Monday, 2 November 2009 22:41:42 GMT