[proaudio] alsamodular synth & spectrum view

[Harald Gutmann <harald.gutmann@xxxxxxx>]

hello!
it's some time ago, when i wondered, that the spectrum view module of the ams doesn't work correct.
but this days this patch appeard in the alsamodular mailing list.

i remerged ams, and patched it that way (but manually).
after that, the spectrum view modul works correct.

maybe someone could be so nice, and include it in the ams ebuild.


hmm... looks like, that the ams isn't in the pro-audio overlay, seems to be the official gentoo tree.
i should better go and fill a bug report.

perhaps it's to late to do such work.
but maybe it's not bed to mention it here in this list.



best regards,
harald gutmann.





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Hi,
"Marius Stoica" <stoicamar@xxxxxxxxx> wrote:


> > I have AMS 1.8.7 on Ubuntu Dapper without the preemption patch installed.
> > I have a problem with the spectrum view; simply it just does not work. It
> > doesn't display anything even when resetting the parameters. Note that the
> > oscilloscope module works fine.
> > 
> > Is anyone there who had the same problem or knows how to fix it?
>   

I just tried this on my (AMD64) system, with the same result. I then
remembered an old problem which manifested here again: Matthias once developed
on SuSE Linux distributions where (at that time) only a single version of the
libfftw and -dev existed, using just float. Nowadays there are always two
versions, one using float (sfftw/sfftw-dev) and one using doubles 
(fftw/fftw-dev). So, the wrong header files are picked up, and the float data
from AMS is passed to the wrong functions (expecting double), resulting in
garbage.

Solution: Get the source code and build it yourself: Edit "spectrumscreen.cpp"
(line 12) and "spectrumscreen.h" (line 15), and in both, change the
#include <rfftw.h>
to
#include <srfftw.h>

Then, do a "make clean" (important) and "make", and things should work then -
at least they do for me, tested with a simple VCO (sine) -> SpectrumView setup.

Of course, you'll need the Qt3 runtime and dev packages, as well as the
fftw2 runtime and -dev packages.

Good luck  :-) ,
Frank

PS: Alternatively, submit a ticket to Ubuntu and have someone fix that package  :) 

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