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

Re: TT and subtitling

From: Chris Lilley <chris@w3.org>
Date: Sat, 1 Feb 2003 00:21:22 +0100
Message-ID: <188989555312.20030201002122@w3.org>
To: "Glenn A. Adams" <glenn@xfsi.com>
CC: public-tt@w3.org, robin.berjon@expway.fr

On Friday, January 31, 2003, 9:11:57 PM, Glenn wrote:

>> -----Original Message-----
>> From: Chris Lilley [mailto:chris@w3.org] 
>> Sent: Friday, January 31, 2003 2:49 PM
>> To: public-tt@w3.org; Glenn A. Adams
>> Cc: robin.berjon@expway.fr
>> Subject: Re: TT and subtitling

>> GAA> One potential issue with the SVG font format is its apparent
>> GAA> lack of support for bitmap as opposed to outline glyph 
>> representations.
>> That is a strength, not a feature. How are you going to cope with a
>> range of display sizes and resolutions with a bitmap font?

GAA> Obviously, if some author used embedded bitmaps, then it is clearly
GAA> sub-optimal for device interoperability. On the other hand in some
GAA> contexts, it might be that the author or perhaps the delivery system
GAA> knows precisely what the required display sizes and resolutions that
GAA> are required.

This ties directly into whether TT is an autoring format, a delivery
format, or both; and also, whether the model is that
many device-specific versions are generated/authored or one portable

GAA> On the other hand, clearly it would be a mistake, and I would
GAA> never advocate sole reliance on use of bitmap representations; I just
GAA> want to be certain that we meet the needs of common authoring and
GAA> delivery systems, where there are many more uses made of bitmap glyph
GAA> downloads than outlines at this time.

True. Then again, there is lots more use of proprietary binary formats
than XML, too, in that area. So change is possible, one hopes.

GAA> One possible way this might be used is as follows:

GAA> 1. authoring and distribution system specify outlines inline;

GAA> 2. emission system that knows device capabilities pre-rasterizes,
GAA> changing outlines to bitmaps;

Yes, that is certainly possible.

GAA> If we fail to define a way to embed bitmaps, then in this scenario,
GAA> the emission system would be forced to use a different content format
GAA> or to extend it in a potentially non-interoperable way.


GAA> I would like to see us be able to support this scenario without
GAA> requiring a different content format or a non-standard extension.

I can certainly understand that.

 Chris                            mailto:chris@w3.org
Received on Friday, 31 January 2003 18:21:24 UTC

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