Hi,
These last few days I found some time to work on ladspa.m.lv2, an LV2
plugin to load ladspa.m.proto instrument definition files:
https://github.com/fps/ladspa.m.lv2
It is in a somewhat usable state, i.e. used in ardour3 it loads the
example instrument generated by this python script:
https://github.com/fps/ladspa.m.proto/blob/master/example_instrument.py
which is a very simple polyphonic sawtooth synth with exponential
envelopes and an echo with differing delay times per voice. There's
still some things to do (e.g. expose control ports, implement
All-Notes-Off midi messages, lots of optimizations - right now I care
more for correctness than for efficiency, etc.) and I also have some
questions:
1] This one is regarding waf. I'm not used to writing wscript files and
I adapted the whole thing from the example sampler from the
LV2-distribution. I wonder how I can make waf to use e.g. -fPIC and
other compiler flags needed for my 64-bit system. Right now I have put a
little makefile into the repository which passes the missing options
along as CXXFLAGS environment variable. This is a dirty hack. So if
anyone waf guru might want to take a look, I'd be so ever grateful.
https://github.com/fps/ladspa.m.lv2/blob/master/makefile
https://github.com/fps/ladspa.m.lv2/blob/master/wscript
2] I'm a little bit puzzled by how the patch_set messages together with
the LV2 worker extension works. If you take a look at this run() function
https://github.com/fps/ladspa.m.lv2/blob/master/instrument.cc#L702
you'll see that I have an extra LV2_ATOM_SEQUENCE_FOR_EACH at the start
of the function to process the patch_set messages. I tried to integrate
that into the loop later on (that iterates over the sample_count frames
and lets the midi events take effect at their respective frame), but
once I do that, patch loading stops to work. I must be missing something
fundamental. So if any LV2 guru might want to take a look, I'd be very
grateful, too
Thanks and have fun,
Flo
--
Florian Paul Schmidt
http://fps.io