W3C home > Mailing lists > Public > public-tt@w3.org > February 2003

RE: Why use time as a unit of measurement? (was: Proposal 0.0)

From: <Johnb@screen.subtitling.com>
Date: Wed, 19 Feb 2003 14:54:52 -0000
Message-ID: <11E58A66B922D511AFB600A0244A722E093EE6@NTMAIL>
To: joeclark@joeclark.org
Cc: public-tt@w3.org

Hi Joe,

> > I guess the question I am asking is - where in SMIL 2.0 
> does it describe how
> > you lock a
> > stream to an **external** clock, that may be stopped,
> > moving at a non 1s to 1s rate, or going backwards **and 
> that may jump**.
> I am not sure this is a good functional model for a timed-text format.

I agree it's not the whole model - but if I'm to use TT for what **I** do
 - this is the functionality I need!

<snip cogent analysis - out of order reels less common now we have video
servers :) >

> Is the issue, then, not a sequence of unique triggers, and not some
> reference to some kind of clock as human beings understand them? In
> theory, we could use Roman numerals to trigger caption display and
> it would still work. Or a sequence of prime numbers. Or a set of
> random numbers so long as no number was repeated and the order of
> presentation were known.

> Yes? No?
Yes, that's certainly a valid viewpoint - the problem is that broadcast
video is 'striped' 
with timecode - not Roman numerals etc :-)

Seriously - I think that what might be required for TT is a 'timesheet' that
the definition of triggers and 'real world' matches as you describe. These
real world matches
could be times, events or detected conditions etc. 

Consider the following possible use for timed text:

A washing machine display.
We wish to display on an LCD the progress of the wash cycle, 
and possibly instructions to the user (e.g. insert conditioner now).
We wish the display to cycle between time remaining and the current cycle 
(e.g. washing, spinning, rinsing etc)
We might also wish periodically to display the chosen program. (cottons,
delicates etc)
All of these text strings might need display for different durations.
Some of the text is variable (e.g. remaining time).
We want a multi-language capability where the user can select language.

I think TT should be able to handle this scenario as easily as

John Birch

The views and opinions expressed are the author's own and do not necessarily
reflect the views and opinions of Screen Subtitling Systems Limited.
Received on Wednesday, 19 February 2003 09:45:39 UTC

This archive was generated by hypermail 2.3.1 : Thursday, 5 October 2017 18:23:58 UTC