[MPlayer-dev-eng] TODO

[Michael Niedermayer]

Hi

On Tuesday 12 February 2002 17:25, Arpi wrote:
[...]
> > On Tuesday 12 February 2002 11:07, Arpi wrote:
[...]
> > > - mencoder: image cut/crop/extend filter, colorspace conversion
> > >   *** Maybe SwScale can do all of these for us?
> >
> > hmm, maybe :)
>
> the crop/extend stuff is external stuff, just affects buffer allocation,
> and can be handled by varrious stride tricks.
> swscale should only do colorspace conversion and scaling at single step.
> afaik it already does such things :)
yes, it could allso do the stride tricks internally, allthough its easier 
externally :)

>
> > [...]
> >
> > > runtime:
> > > - add --enable-runtime or something (should change VERSION header and
> > > enable runtime cpu detect and print banner telling users to recompile
> > > for speed) - runtime cpu detection in:
> > >      vo_dga.c (asm stuff may be removed and replaced by fastmemcpy?)
> >
> > the current fastmemcpy is perhaps not optimal for mem -> agp/pci copies
> > because it assumes that read/writes go over the same bus, so it simply
> > reads a few kb (they are in the L1 cache after that) and then reads them
> > again and stores them (the trick is from amd's manual not from me ...)
> > if both source &  destination are in main mem then the bus will be 100%
> > busy cuz the data is read from L1 cache on the read/write pass and the
> > accesses will be sequential instead of alternating between 2 locations so
> > its faster but if the destination is on an agp card than the agp bus will
> > be idle 50% of the time and the mem bus will be idle the other 50% ...
> > pretty bad allthough i didnt benchmark the mem->agp variant so its just
> > theory ...
>
> hmm. try it, i wanna see a 2 times faster agp_memcpy() :)
simply comparing the asm memcpy version in vo_dga against fastmemcpy
./mplayer -nosound 
~michael/videos/Lorenna_McKennit-Mummers_Dance-Mononoke_Hime-gabucino.avi -vo 
dga -benchmark

fastmemcpy:
BENCHMARKs: V:   8.666s VO:   2.516s A:   0.000s Sys:   4.344s =   15.526s
BENCHMARK%: V: 55.8162% VO: 16.2078% A:  0.0000% Sys: 27.9760% = 100.0000%

vo_dga asm:
BENCHMARKs: V:   8.726s VO:   2.019s A:   0.000s Sys:   4.372s =   15.117s
BENCHMARK%: V: 57.7245% VO: 13.3552% A:  0.0000% Sys: 28.9203% = 100.0000%
[...]

ill write a agp_memcpy ...

Michael