Re: [libdv-dev] Re: API Change / slowdown !

[Stefan L. <lu...@sn...>]

On Don, 23 Nov 2000, Charles 'Buck' Krasic wrote:
> Hmm.  
> 
> Some of my changes could effect performance, mainly due to cache
> footprint issues.
> 
> However, I just tried a similar test and got only a very slight
> difference.  (~0.15s for 150 frames).  (I used -D 2000-11-20).
> 
> Did you run your test several times to ensure warm filesystem caches?
Yes, previous values where for a PAL sequence.
Now I tried it with pond.dv.
old time playdv:
 180 frames displayed

real    0m11.663s
user    0m9.760s
sys     0m0.310s

new time playdv:
Displayed 180 frames in 14.2 seconds

real    0m14.334s
user    0m12.490s
sys     0m0.130s   

My systems is a AMD K6/2 400 128 MB RAM
Matrox G400
kernel 2.4.0-test10
plain X11 V4.0.1

disk speed:
jarada:~ # hdparm -tT /dev/hda

/dev/hda:
 Timing buffer-cache reads:   64 MB in  1.09 seconds =58.72 MB/sec
 Timing buffered disk reads:  32 MB in  1.98 seconds =16.16 MB/sec    


> Stefan Lucke <lu...@sn...> writes:
> 
> > Hi Buck,
> 
> > I just compared lastest version (with if (Success == Xv ....))
> > with a version checked out with option -D 2000-11-20 (without API change
> > but YUY2.c changes).
> 
> > Runtime difference is about 2.7 seconds in user mode for a 150 picture
> > sequence (for 10 seconds to 13 seconds). I used '-mcpu=i686 -s -O6' as
> > compile options.
> 
> > old time playdv:
> > real    0m13.189s
> > user    0m10.690s
> > sys     0m0.410s
> 
> > new time playdv:
> > real    0m15.769s
> > user    0m13.310s
> > sys     0m0.210s
> 
-- 

mfg

  Stefan Lucke (lu...@sn...)