archives/Re: [theora-dev] First steps towards a simple textstream format.

Philip Jägenstedt philipj at telia.com
Sun Aug 10 11:03:30 PDT 2003



Hi again.

On Sun, 10 Aug 2003 18:14:59 +0200
<GODA-XEN at terra.es> wrote:

> the first reason is the coollnes, but using my metod, the space saved is
> good and in the worst scenario ( this is near to imposible) only the table
> biger than the utf8 eqivalent, but the table not only mape character to
> character, they can map a set of consecutive character only maping the fist
> an the last plus a indicator, the table in any case isn't biger than 1~2K,
> and is only put in the begining of the subtitle.

I guess my objection is that it simply isn't worth while. Text is so
small compared to audio and video that it's just not worth compressing
most of the time. Also, keeping it very simple makes it a whole lot
easier for a third party to add support for the format.

> For me the use of a endebed font isn't a obligation, but its ineresting to
> ad this posiblility, Im a part of a spanish fansub and i know the real
> problem and needs of
> a subtitle format, and teh USF is very ambitious and surpas a lot every real
> ned of a subtitle format, In my draft the endebed font is a posibility not a
> obligation, the use is retricted wen isn't used de default font, but this
> can be recomendable in some cases. in the reality the endebed font can de
> unnecesari but it save the problem in a hardware implemetation of wen they
> don't have a complete UTF8 font ( 8MBytes aprox), this equal the hardwarw
> language compatibility with the actual dvd subtitle implemetation and the
> nmg format.

Lack of a complete UTF-8 font would be a problem. Embedding a font
certainly isn't a bad idea per se, but I'm just questioning if it
belongs in a simple subtitle format like I had imagined. There are
several difficulties facing embedded fonts. First of all -- in which
format should the font be embedded? postscript, truetype, type1, or some
other format? If you go with say truetype, would your implementation do
the rendering, or should the player use libfreetype to render the text?

These are by no means insurmountable problems, but I'm just thinking
that such things could be left to something bigger and better. Yes, SVG
has support for embedded fonts, in its own format. Of course putting SVG
into ogg and figuring out how to render it isn't easy, but I really do
think it would be a cooler thing to do than reinventing such
functionality like USF seem to be doing.

Have you got any formal specs of your format I can look at?

// Philip Jägenstedt
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