[MPlayer-dev-eng] [PATCH] dynamic font generation

[Michael Niedermayer]

Hi

On Thursday 15 August 2002 19:01, Jindrich Makovicka wrote:
[...]
> > yea, but think of chinese etc. they have very large fontsets with few
> > thousand chars, it's where it matters.
>
> Well, I actually sent a wrong version which was "pessimized" and
> performed even worse than the original :(
> Regarding the font generation, most cpu-hungry is the outliner, because
> its complexity is O(thickness^2*fontwidth*fontheight),
> gaussian is O(radius*fontwidth*fontheight), font rendering is the
> easiest thing. With fontwidth I mean character width*count of course.
imho O() is pretty useless for practical speed comparission, anyway u can 
approximate gaussian blur very well in O(width*height) with repeated box blur 
but i dunno at which radius it would be faster
and outline isnt that bad either as u can skip the completly black & white 
areas
it might be possible to calculate the outline in O(thickness*w*h) if u are 
crazy, by reusing the max of the inner (=1.0) part of the antialiased circle 
whos pixels are used as weights for the max function

>
> Anyway, scanning the subtitles for all characters is maybe worth the
> effort, especially for chinese at al.
hmm, or generating them when they are needed instead of all at once might 
avoid some problems, like not knowing all future displayed chars (network 
stream, ...)

[...]

Michael