ISSUE-35: opacity is specified as a float value

opacity float value

opacity is specified as a float value

TTML 1.0
Raised by:
Sean Hayes
Opened on:
opacity is specified as a float value, implying an inordinate (and completely untestable) set of gradations of alpha; while colour alpha is specified as only 255 steps.
A possible type for <alpha> :

<simpleType name='alpha'>
<restriction base='decimal'>
<totalDigits value='4'/>
<fractionDigits value='3'/>
<minInclusive value='0'/>
<maxInclusive value='1'/>

Related Actions Items:
No related actions
Related emails:
  1. Agenda for TT telecon 9th April (from on 2009-04-09)
  2. [minutes] Timed Text Working Group Teleconference 20090220 (from on 2009-02-20)

Related notes:

Philippe Le Hégaret, 9 Dec 2008, 14:07:17

This needs an update to the schema (ISSUE-53)

Philippe Le Hégaret, 20 Feb 2009, 16:25:24

resolved in TTAF1-DFXP 20090415 update

Glenn Adams, 16 Apr 2009, 02:53:04

Display change log ATOM feed

David Singer <>, Nigel Megitt <>, Chairs, Thierry Michel <>, Philippe Le Hégaret <>, Staff Contacts
Tracker: documentation, (configuration for this group), originally developed by Dean Jackson, is developed and maintained by the Systems Team <>.
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