David, and all:
Regarding the following paragraph in an e-mail from David:
This is controlled by the synth.overflow.* parameters which I
implemented a while ago to give you others some room for experimenting
with which settings work best. I don't remember if I got any feedback
for changing the default parameters.
It may well be that the implementation of the "overflow" parameter
functionality was the beginning of when fluidsynth lost its ability to
successfully play my compositions.
I would like to experiment with the parameter, but in looking at the
help info from fluidsynth, it is not self-evident (to me) how to use it,
or what it does.
I searched for more documentation, but didn't find it.
Could you please explain the various overflow parameter settings, and
what they do?
Also, is it possible to specify the overflow parameters in Qsynth?
--
Thank You,
Aere
-----Original Message-----
*From*: David Henningsson <address@hidden
<mailto:address@hidden>>
*To*: FluidSynth mailing list <address@hidden
<mailto:address@hidden>>
*Subject*: Re: [fluid-dev] problems with fluidsynth 1.1.6 on a raspberry pi
*Date*: Tue, 20 Nov 2012 22:57:39 +0100
On 11/20/2012 08:58 AM, Jan Newmarch wrote:
Hi
I recompiled 1.1.6 with polyphony set to 64. There doesn't seem to be a
command line option to reset parameters like this, but it shouldn't be
too hard to add one. Yes I know, use fluid_settings_setXXX in the code...
The option is:
"fluidsynth -o synth.polyphony=64"
see "fluidsynth -o help" for more settings.
Unfortunately it does not seem like the interpolation method is settable
in the same way, which seems strange to me. You have to do it inside the
shell.
Turning off reverb and chorus, as suggested by others, is done by "-o
synth.reverb.active=False" and "-o synth.chorus.active=False", which
might also speed up fluid_rvoice_buffers_mix (no need to render into
reverb and chorus buffers).
Anyway... no better. Still hits CPU above 99% (!) and distorts
accordingly.
(The pidstat command I used was
pidtat -C fluidsynth - u -r 5
for 5 second periods.)
David gives perf figures of
30% - fluid_rvoice_dsp_interpolate_4th_order
27% - fluid_rvoice_buffers_mix
13% - fluid_iir_filter_apply
9% - fluid_revmodel_processmix
I ran perf (from linux-tools Debian pkg) on the RPi for nightsin.kar using two
soundfonts and got
32.07% fluid_rvoice_buffers_mix
26.89% fluid_rvoice_dsp_interpolate_4th_order
12.99% fluid_iir_filter_apply
11.00% fluid_revmodel_processmi
for the FluidR3_Gm and
29.49% fluid_rvoice_buffers_mix
23.71% fluid_rvoice_dsp_interpolate_4th_order
14.89% fluid_revmodel_processmix
12.53% fluid_iir_filter_apply
for the GeneralUser soundfont (which sounds a bit better).
No significant difference.
Thanks, seems like the statistics are about the same; with
fluid_rvoice_buffers_mix being on the top.
Are you running this with floats or doubles, (-Denable-floats=on when
compiling for single-precision floats) and is there a significance in
performance?
Jan
--
On Sun, 2012-11-18 at 08:31 -0700, Aere Greenway wrote:
Jan & David:
In my opinion, limiting the polyphony (I presume that is what you mean
by "limiting the voices") does not adversely affect the sound.
What is using up the CPU, is voices still being 'sounded' that have
long before faded to where they are inaudible. sysstat
If Fluidsynth works similarly to the EMU10K1/2 (Soundblaster & Audigy)
chip, it should 'take-out' the oldest voices first, though I don't
know if that is actually the case.
This is controlled by the synth.overflow.* parameters which I
implemented a while ago to give you others some room for experimenting
with which settings work best. I don't remember if I got any feedback
for changing the default parameters.
// David