On Sun, 20 Aug 2006 19:40:00 +0200
"Diego Sáenz" <[EMAIL PROTECTED]> wrote:
> For non X apps (games that do not need the X overhead)
> another APIs was intended a vgalib and later the svgalib,
> wich do not support ega or vga because a vgalib do it.
> Later a vm86 call was included for dosemu and enhanced a pair of times.
Speed was of more concern at that time than using X11 or not.
(X11 was slow is slow and most probably will stay slow)
Thus specialized libraries were invented to help those programs
that need it.
> When linux was ported to hardware without text modes (mac, amiga, atari, ...)
> each need a framebuffer driver below the console code and it end caming
> to x86 too standarizing framebuffers in that step. But even now in the
> kernel there is 2 amiga drivers for s3 64 and virge amiga version
> cards(ciblade) that only works in amiga linux with coments about make it
> work in x86 and etc.
What is your point here?
> Other video apps chosse to use direct hardware access with kernel help(DRI)
> or not and support a lot of video drivers (like sdl, directfb,
> mplayer(cvs version have a virge video driver), ...)
Hmm.. let's take this apart.
sdl was designed as a common library to make it easier to port
games. It was able to use many different output systems to enable
the game programmers (and users) to switch between different
output systems without the need to rewrite half of the code.
Video players picked up sdl because it offered an easy access
to some video output systems that were at that time not supported
by the players themself (though, afaik most of these are now).
What exactly the reason of directfb was, i cannot say. But
i guess it was speed compared with the very slow fb driver.
> There are other video proyects like ggi that uses a kernel
> driver but i unknown how is it now.
GGI tried in the beginning to be the unified video output
driver everyone wanted. Though they got caught in many issues
including featuritis and problems in the API design.
> I unknown largely *BSD, but think it have some problems.
> I only known that there is a video library called
> vidix(not only for BSD but for unix) used by mplayer
Vidix was originialy implemented to allow fast access to
graphic cards for video player applications in the same way
as mga_vid does (that's why its code is so similar) before
Xv existed.
Nick tryed to make it OS and graphic card independend, thus
it is a user space driver, comparable to how xf86/xorg drivers work.
But as Nick only knew ATI cards back then, it was too much tailored
for ATI cards and never really got off. Today it supports a hand
full of cards (ati, nvidia, mga and a few more exotic), but is hardly
used as most of these cards are supported by Xv.
I don't know exactly how widely vidix is still used, but considering
the amount of bugreports MPlayer gets and the last patch that part
saw, i'd say it's pretty much dead.
I generally fail to see your point. You listed a few things
that happend in the past, with aperantly little understanding
of the how and why. And you forgot to draw a conclusion.
Attila Kinali
--
心をこめて聞け心をこめて話せ
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