Filipe wrote: > Just posting some useful information here. > > zita-reverb was recently updated, making the ladspa versions match the > standalone. > the official announcement is here: > http://lists.linuxaudio.org/pipermail/linux-audio-user/2013-August/094259.html > > > regarding the "indefinitely" loud issues, it seems to me that it's > just denormals. > there's lots of useful information about this on wikipedia: > https://en.wikipedia.org/wiki/Denormal_number
Could be. I'm just wondering, if those are the culprit, then why does the issue only trigger occasionally? Seems to me that a deterministic DSP would produce denormals from the same input every time... or am I missing something here? > The "Disabling denormal floats at the code level" is specially useful > for LMMS. > > AFAIK the usual procedure to avoid denormals is as follows: > > On the engine code, include the headers needed for _mm_getcsr/_mm_setcsr > > #include <xmmintrin.h> > > > When the engine thread is initializing call this: (on all the threads > that do audio-processing) > > _mm_setcsr( _mm_getcsr() | 0x8040 ); > > > The plugins and LMMS engine/audio code will need to be built with > fastmath and SSE2, the gcc arguments are: > > -ffast-math -mtune=generic -msse -msse2 -mfpmath=sse > > > Note that this requires SSE2. > But if LMMS does this, the issue with denormals will very likely go away. > > > PS: I tried building the full LMMS code with "-ffast-math", but that > breaks the timeline. > So if this is going to be introduced it will need to be carefully > selected (only audio engine and plugins). Thanks for the info. We've considered denormal-stripping and SSE2 before, but nothing came of those discussions - IIRC, it was thought that there wasn't enough benefit in doing so... but maybe that could be re-evaluated now, if it could prevent issues with fx plugins. ------------------------------------------------------------------------------ Comprehensive Server Monitoring with Site24x7. Monitor 10 servers for $9/Month. Get alerted through email, SMS, voice calls or mobile push notifications. Take corrective actions from your mobile device. http://p.sf.net/sfu/Zoho _______________________________________________ LMMS-devel mailing list LMMS-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/lmms-devel
