ISSUE-154: Clarify the endsync behavior

endsync behavior

Clarify the endsync behavior

State:
CLOSED
Product:
TTML 1.0
Raised by:
Sean Hayes
Opened on:
2012-02-15
Description:
Summary:
Time containers should have a default value of endsync=’all’ rather than the current default endsync=’last’, otherwise marker mode does not work.

Detail:
In SMPTE discontinuous mode TTML defines time containers to use the marker mode (event based) timing model of SMIL; however in this mode the elements inside a time container are not waiting for events unless the parent timecontainer is active. However unless the parent duration is explicitly notated, since all of the children are event based they would under SMIL have no resolved active time, which in the default endsync model results in a parent with zero duration.

I think we can most simply resolve this issue by defining that time containers have a default value of endsync=’all’ rather than the SMIL default endsync=’last’. This means that the parent will stay around until all of the children have completed at least one activation, which is a more intuitive expectation for a caption file anyway.
Related Actions Items:
Related emails:
  1. {minutes} TTML Agenda for 31/5/12 (from glenn@skynav.com on 2012-05-31)
  2. Re: ISSUE-154 (endsync behavior): Clarify the endsync behavior [DFXP 1.0] (from tai@irt.de on 2012-05-31)
  3. RE: {minutes} TTML Agenda for 12/4/12 (from mdolan@newtbt.com on 2012-04-17)
  4. {minutes} TTML Agenda for 12/4/12 (from glenn@skynav.com on 2012-04-12)
  5. RE: TTML Agenda for 12/4/12 (from geoff_freed@wgbh.org on 2012-04-11)
  6. {minutes} TTML Agenda for 5/4/12 (from glenn@skynav.com on 2012-04-05)
  7. {minutes} TTML Agenda for 22/3/12 (from glenn@skynav.com on 2012-03-22)
  8. {status} [was Re: TTML Agenda for 8/3/12] (from glenn@skynav.com on 2012-03-08)
  9. [TTWG] Draft Minutes (was: Re: TTML Agenda for 1/3/12) (from glenn@skynav.com on 2012-03-01)
  10. [Minutes] TTML Agenda for 23/2/12 (from glenn@skynav.com on 2012-02-23)
  11. Re: TTML Agenda for 23/2/12 (from geoff_freed@wgbh.org on 2012-02-22)
  12. Re: TTML Weekly meetings (from glenn@skynav.com on 2012-02-16)
  13. ISSUE-154 (endsync behavior): Clarify the endsync behavior [DFXP 1.0] (from sysbot+tracker@w3.org on 2012-02-15)

Related notes:

closed resolution 31/5/12

Sean Hayes, 31 May 2012, 20:41:58

Changelog:

Created issue 'Clarify the endsync behavior' nickname endsync behavior owned by Sean Hayes on product DFXP 1.0, description 'Summary:
Time containers should have a default value of endsync=’all’ rather than the current default endsync=’last’, otherwise marker mode does not work.

Detail:
In SMPTE discontinuous mode TTML defines time containers to use the marker mode (event based) timing model of SMIL; however in this mode the elements inside a time container are not waiting for events unless the parent timecontainer is active. However unless the parent duration is explicitly notated, since all of the children are event based they would under SMIL have no resolved active time, which in the default endsync model results in a parent with zero duration.

I think we can most simply resolve this issue by defining that time containers have a default value of endsync=’all’ rather than the SMIL default endsync=’last’. This means that the parent will stay around until all of the children have completed at least one activation, which is a more intuitive expectation for a caption file anyway.' non-public

Sean Hayes, 15 Feb 2012, 12:39:27

Status changed to 'closed'

Sean Hayes, 31 May 2012, 20:41:58


David Singer <singer@apple.com>, Nigel Megitt <nigel.megitt@bbc.co.uk>, Chairs, Thierry Michel <tmichel@w3.org>, Philippe Le Hégaret <plh@w3.org>, Staff Contacts
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