rbultje@xxxxxxxxxxxxxxxxxxx wrote:
Hey Steve,
On Fri, 2003-02-28 at 17:27, Steve Miller wrote:
To get this I
did some functions with mmx inline assembly, and vastly simplified the
interface to the decoder. It currently decodes only yuv422 8 bit
interleaved.
Funny, since that already exists. ;-).
http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/mjpeg/jpeg-mmx/
If you want, you could have a look at that too.
Ronald
Hi Ronald,
Actually I did look at it. I never could get the color conversion mmx
code to work for me. I had to redo that and the idct function because I
use a slightly different buffering scheme, and also added mmx upsampling
(which gained a couple of fps). A lot of the speed up came from
eliminating the genericness of libjpeg, trying to reduce the number of
loops, and generally making the code smaller. Getting an entire loop
into cache greatly helps. The camera I have spits out 30 fps VGA, and I
was unable to find anything else that even came close to keeping up. I
haven't had time recently to work more on it, but if anyone wants to
play with it let me know.
Steve
--
Steve Miller
Software Engineer
STMicroelectronics
phone (602) 485-2014
