In the meantime, it has worked for us in the past to add just a tiny bit of noise~ to the freeverb~ input 100% of the time. I haven't tried in about a year so things may have changed.
Matt On Fri, Aug 14, 2009 at 7:07 AM, Ed Kelly<[email protected]> wrote: > We have to sort this out! > > The denormals bug in freeverb~ _seems_ to have been fixed by following > Julius' advice. I made a makefile with > > -fno-trapping-math > > as a flag and so far so good. I haven't had a problem with the freeverb~ > object pegging the CPU. May I advise that this is implemented in PD-extended, > since it causes my patch to NOT WORK AT GIGS! I simply cannot take any more > embarrassment. I want to play live, otherwise there's simply no point doing > anything! > > The second one I have discovered is in bsaylor/svf~ and there's no makefile > for this in the subversion repository. I notice in the source code there is a > FLUSH_TO_ZERO definition. Interestingly, when I try to compile this external > using a bog-standard makefile on Ubuntu 8.10, it causes an error: > > cc1: warnings being treated as errors > svf~.c: In function ‘run_svf’: > svf~.c:59: error: dereferencing type-punned pointer will break > strict-aliasing rules > svf~.c:60: error: dereferencing type-punned pointer will break > strict-aliasing rules > > Now, I'm trying to unpick the statement: > #define FLUSH_TO_ZERO(fv) (((*(unsigned int*)&(fv))&0x7f800000)==0)?0.0f:(fv) > > which is being called on lines 59 and 60 of bsaylor/svf~.c, causing the > compiler to choke, and (perhaps) causing my drumsynths to break! > > And by the way, where is the source code for the _other_ svf~ external? > > Ed > > --- On Wed, 1/7/09, Julius Smith <[email protected]> wrote: > >> From: Julius Smith <[email protected]> >> Subject: Re: [PD] bug in freeverb??? >> To: "Matt Barber" <[email protected]> >> Cc: [email protected] >> Date: Wednesday, 1 July, 2009, 8:22 PM >> Hmmm, this sounds like underflow >> traps ("denormals"). You should >> also be able to add a small constant to the input signal. >> >> I notice gcc has the option >> >> -fno-trapping-math >> >> which may make the problem disappear if my theory is >> correct. (I >> hope the FPU simply sets underflows quietly to zero when no >> trap can >> be generated.) >> There is also >> >> -ffast-math >> >> which is more aggressive. >> >> - jos >> >> At 11:30 AM 7/1/2009, Matt Barber wrote: >> >We have also had this problem, and have found that >> normally one can >> >avoid it by salting the [freeverb~] object with a >> minuscule amount of >> >noise at all times. >> > >> >Matt >> > >> > >> > >> > > Message: 5 >> > > Date: Wed, 1 Jul 2009 09:57:43 -0700 (PDT) >> > > From: Andres Ferrari <[email protected]> >> > > Subject: [PD] bug in freeverb??? >> > > To: [email protected] >> > > Message-ID: <[email protected]> >> > > Content-Type: text/plain; charset=iso-8859-1 >> > > >> > > >> > > when is connected into freeverb any signal >> multiplied by zero >> > > the CPU usage begin to up and up to the limit, >> and if the patch >> > is heavy by far exceeds the 100%....sound and >> everything becomes a mess. >> > > >> > > This happens to me only in leopard. >> > > >> > > In osx 10.4 (ppc) and windows I've never had that >> problem. >> > > Andr?s Ferrari G. >> > > >> > > http://www.myspace.com/anfex >> > > >> > >> >_______________________________________________ >> >[email protected] >> mailing list >> >UNSUBSCRIBE and account-management -> >> >http://lists.puredata.info/listinfo/pd-list >> >> >> Julius O. Smith III <[email protected]> >> Prof. of Music and Assoc. Prof. (by courtesy) of Electrical >> Engineering >> CCRMA, Stanford University >> http://ccrma.stanford.edu/~jos/ >> >> >> _______________________________________________ >> [email protected] >> mailing list >> UNSUBSCRIBE and account-management -> >> http://lists.puredata.info/listinfo/pd-list >> > > Send instant messages to your online friends http://uk.messenger.yahoo.com > > > _______________________________________________ > Pd-dev mailing list > [email protected] > http://lists.puredata.info/listinfo/pd-dev > _______________________________________________ Pd-dev mailing list [email protected] http://lists.puredata.info/listinfo/pd-dev
