RE: Roll-up captions in WebVTT

Ian Hickson wrote:
>
> > On Tue, 29 Nov 2011, Silvia Pfeiffer wrote:
> >
> > Only if you replicated it identically.
> 
> We will _never_ be able to identically replicate TV broadcast (e.g. the
> font will be different, or the resolution will be different, or the
> scaling algorithm will be different, or we'll drop different frames, or
> the monitor calibrated differently).
> 
> So some differences are clearly acceptable.
> 
> So it's merely a question of negotiating.

I think here the emphasis is on the wrong word; it's not that we cannot
replicate a [TV broadcast + captioning], but rather that we cannot do so
*identically*. 

Never is a big word.


> 
> On Tue, 29 Nov 2011, David Singer wrote:
> >
> > I think a fundamental question that needs addressing is whether we
> > expect roll-up to be (a) 'part of' the core VTT vocabulary or (b) a
> > presentational issue that is 'optional'?
> 
> 
> In conclusion, I think it has to be at least (a), though it would be
> cool
> to allow (b), though I don't really see how to do it.

When the Accessibility Task Force looked at caption requirements, the need
for allowance of mixed display styles was captured then:

	[CC-14] Allow the use of mixed display styles - e.g., mixing
paint-on captions with pop-on captions - within a single caption cue or in
the caption stream as a whole. Pop-on captions are usually one or two
lines of captions that appear on screen and remain visible for one to
several seconds before they disappear. Paint-on captions are individual
characters that are "painted on" from left to right, not popped onto the
screen all at once, and usually are verbatim. Another often-used caption
style in live captioning is roll-up - here, cue text follows double
chevrons ("greater than" symbols), and are used to indicate different
speaker identifications. Each sentence "rolls up" to about three lines.
The top line of the three disappears as a new bottom line is added,
allowing the continuous rolling up of new lines of captions.

Also captured was the need:

	[CC-27] Support live-captioning functionality.

http://www.w3.org/WAI/PF/media-a11y-reqs/#captioning 

For these reasons I think that WebVTT should be supporting roll-up
captioning, despite its shortcomings. I do not think we should be in a
position of saying _NO_ outright, but rather that we should support all
capabilities in existence (to the extent possible) and then lead through
education and outreach, teaching content producers best practices.


> > On Tue, 29 Nov 2011, Christian Vogler wrote:
> >
> > Aside from that, we still have to recognize that even if these issues
> > are solved, and even if we effect a shift away from roll-up to pop-on
> > captions over time, the fact is that these types of captions are
> still
> > in widespread use. If WebVTT does not support them, there will be a
> gap
> > between what is required by the broadcasters and by FCC rules to be
> > supported on the web and what the standard actually supports.
> 
> I feel this is a highly US-centric attitude. The volume of content over
> which the FCC has jurisdiction is miniscule compared to the volume of
> captioned content on the Web as a whole.

While this may indeed seem very US-centric, it does not make it any less
real or important.


> 
> 
> > In this case, one of two things would happen: there would be calls
> for
> > yet another standard that would take who-knows-how-long to figure
> out,
> > or broadcasters would make the argument that showing captions on the
> web
> > is not technically and economically feasible. In either case,
> > accessibility would be set back for a long time.
> 
> Or maybe the people involved might realise that they would make more
> money, and content would be more accessible, if they instead used the
> higher-quality captioning techniques. I don't see why we have to assume
> that the FCC and the traditional broadcasters are unable to see this.

See "...teaching content producers best practices", above.


> 
> > FCC will likely issue a Report and Order in January mandating that
> > captions be of equal or greater quality than what was shown on TV.
> 
> Well changing them from roll-up to pop-up would achieve that easily
> enough...

IANAL, but in my experience lawyers have funny ways of interpreting words
like "equal" - just saying...


JF

Received on Tuesday, 6 December 2011 00:39:15 UTC