[FFmpeg-devel] libavutil simd

Rich Felker dalias
Wed Oct 3 06:30:06 CEST 2007

On Tue, Oct 02, 2007 at 09:46:20PM +0200, Michael Niedermayer wrote:
> Hi
> On Mon, Oct 01, 2007 at 09:27:46AM +0200, Michael Niedermayer wrote:
> > Hi
> > 
> > On Mon, Oct 01, 2007 at 12:27:12AM -0600, Loren Merritt wrote:
> > > Any objections to moving cputest.c and related code to libavutil? I'd like 
> > > to simd some of the lavu functions, but cpu detection depends on lavc.
> > 
> > cputest.c + the parts needed from the headers are ok
> btw, it would be very nice if compile time selection of features where
> possible (in addition to runtime for x86)
> that would reduce libavutils size for people who compile their own
> (its kinda silly to have a lib filled with code which is never used)

It would also increase performance by a small but noticable amount, I
think. Direct calls are much faster than indirect calls on some cpus,
especially my K6. Might need to call the dsputil functions through
some sort of macro that takes the dsp context as an argument so that
it can either use the function pointers in the context or a direct
call depending on the build options..


More information about the ffmpeg-devel mailing list