Re: About xvid source assembly language optimize(why it does not work?)
Michael Militzer <[email protected]>
| Newsgroups | gmane.comp.video.xvid.devel |
|---|---|
| Message-ID | <[email protected]> |
Hi, make sure you really compiled xvid with assembly optimizations enabled. You need yasm or nasm present - or otherwise xvid will be compiled with c-code only. Also note that the -m option will write out data to your disk. It might be that more time is spent on I/O than on the actual decoding. In that case, asm and noasm options could seem to perform similar. Regards, Michael Quoting ?? <[email protected]>: > Dear Everybody: > > I download the xvid 1.1.3 source code , and i compiled the > source under Fedora Core 8. > Then I compile xvid_decraw.c. > And I run with the command: > > ./xvid_decraw -i input.m4v -m > then it work well, and output the bitmap file. but it is rather slow. > Then I use the command below: > ./xvid_decraw -i input.m4v -asm -m > Hence I think i used -asm option , the decoding speed should be > accelerated. > > But .... I find that the result is unchanged with the non-asm > execution result . > > input.m4v is a raw 720x568 mpeg4 video sequence, . > > I wonder whether the -asm option worked! > > So i test the fdct and idct, they have been assigned to > fdct_mmx_skal and idct_mmx respectly. > > But why it does not accelerate? > > So i use a small script to test the fdct_c and fdct_mmx_skal. > To run 1000000 times , > the fdct_c consume 2.7 seconds and fdct_mmx_skal need 0.8 second > on my computer. > It seems that asm code should be much faster. But why xvid > decoding can not be speeded up? > > Thanks very much ! > > > > 2008-11-18 > > > > Ice Lee > _______________________________________________ > XviD-devel mailing list > [email protected] > http://list.xvid.org/mailman/listinfo/xvid-devel > >