[LAD] [Ardour-Users] TAP EQ issues, revisited

[Steven Chamberlain]

Hi,

There was a thread on LAD two years ago, almost exactly, pointing out
the denormal problems in TAP's EQ plugins:
http://linuxaudio.org/pipermail/linux-audio-dev/2005-August/013367.html

Unfortunately the problem was never fixed.  Many people are still having
issues with 'TAP Equalizer' and 'TAP Equalizer/BW', as there are recent
posts in ardour-users regarding spiralling CPU usage for DSP.

I've been doing my best to debug and fix the problem, but now that I
actually want to reproduce the problem, I can't!  I can't reproduce the
jump in CPU usage, although I suffer a loss of audio in Ardour when I
have many TAP EQ's running in a session.

So, I tried a few small changes to tap-plugins-0.7.0 which seemed to fix
the loss of audio.  If anyone can reliably reproduce the jump in CPU
usage (which usually triggered by periods of silence in the middle of a
recording), then please try rebuilding the TAP plugins from source, with
and without my attached patch, and see if it helps.

Please note, if your current tap_eq.so and tap_eqbw.so are already
installed in /usr/lib/ladspa/, you may need to edit the Makefile and
remove "local/" from the .so and .rdf install paths.

I'm hopeful that this might cure denormal problems that some people have
suffered from with these plugins for years.  If this works, I will test
many more plugins for the same problem and perhaps fix those, too.

Thanks!
-- 
Steven Chamberlain
steven at pyro.eu.org
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