On Fri, 2009-10-16 at 18:53 -0700, Chris Healy wrote: > Arjan, > > I did even more analysis on this subject and better understand what is > causing the CPU burdon. > > In Moblin, PulseAudio is configured to perform re-sampling using the > 'src-linear' method based on the config in /etc/pulse/daemon.conf. > > Re-sampling happens when you have an audio source that is encoded at a > different sample rate than PulseAudio's default sample rate. > > Example would be PulseAudio is set to run at 48Khz, but I have an mp3 that > is encoded at 44.1Khz. (Pretty common.) > > In daemon.conf, there a number of methods allowed for re-sampling. I tried > some of the different versions and it seems that it would be better to have > the re-sample method set to 'ffmpeg' as a default as most people say it is > of higher quality than 'src-linear' and I experienced a 10% drop in CPU > usage by PulseAudio. (It was taking as much as 25% on my Atom Z520 based > HW) > > Regardless, it takes at least 15% of the CPU to do the sample-rate > conversion which is unfortunate, but necessary when you have dissimilar > sampling rates. > > Do you think PulseAudio daemon.conf was set to 'src-linear' on purpose for > Moblin or is this just a default that was inherited and should possibly be > changed in Moblin to better work with the Atom?
oh... yea, src-linear is not a default but something explicitly set in attempting to work around an issue that ended up being solved in a different way. So... we have no good reason to use this configuration. I filed a bug capturing the issue and marked it as critical since I think this is going to have a significant impact to the overall system + its a very low risk thing to fix. http://bugzilla.moblin.org/show_bug.cgi?id=6896 --rusty _______________________________________________ Moblin dev Mailing List dev@moblin.org To manage or unsubscribe from this mailing list visit: http://lists.moblin.org/listinfo/dev or your user account on http://moblin.org once logged in. For more information on the Moblin Developer Mailing lists visit: http://moblin.org/community/mailing-lists
