[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [fluid-dev] Testing synth.overflow parameters - more questions

From: Aere Greenway
Subject: Re: [fluid-dev] Testing synth.overflow parameters - more questions
Date: Sun, 27 Jan 2013 21:50:24 -0700
User-agent: Mozilla/5.0 (X11; Linux i686; rv:17.0) Gecko/20130106 Thunderbird/17.0.2

On 01/27/2013 08:15 PM, David Henningsson wrote:
On 01/27/2013 09:35 PM, Aere Greenway wrote:
David and all:

One more thing I need to know, to try different values for the
"synth.overflow.volume" parameter, is what range of numbers are produced
from the "volume_score" and "attenuation" calculations.  Is tho
"volume_score" just the value from the MIDI volume, velocity, and
expression values?  Added together? Is "attenuation" that value,
multiplied by a number between 0 and 1.0?

Hi, and thanks for experimenting with it.

The attenuation is based on the attenuation modulator it seems like. It ranges from 0.1 to 1440, where 1440 is the softest ( -96 dB) and the calculation is (volume_score / attenuation).

There are default modulators in a soundfont for making the MIDI note velocity as well as CC 7 (main volume) and CC 11 (expression) affect the attenuation, but this can be overridden by the soundfont.

// David


Thanks for the additional information.

I tested this primarily on SUSe Linux, where I can't install your PPA (that I re-packaged). My hope was that I would be able to work around the problem with libfluidsynth 1.1.5-3.1.2 by configuration changes.

For all this testing, I used a polyphony parameter of 64.

I was not able to configure my way out of the problem with 1.1.5. There is a real problem in that level (which most users now have), which is fixed in 1.1.6.

I did a lot of testing with my most demanding pieces, and my configuration changes did not change the sound in any obvious way. Here is the fluidsynth command I last tested with:

fluidsynth -a pulseaudio --chorus=no -o synth.polyphony=64 -o synth.overflow.age=8000.0 -o synth.overflow.released=-6000.0 -o synth.overflow.sustained=-4000.0 /dos/Shared/SoundFonts/FluidR3_GM122501.SF2

My thinking was to to make released (and not sustained) notes the first candidates for scavenging, followed by sustained notes, trying to have recent notes be less-likely to be taken-out.

I connected to it (for output) with my new MIDI device, using both the integrated MIDI player and the keyboard, simultaneously.

I tried (with the sustain pedal held down) multiple ascending and descending full-keyboard glissandos, and the sound was as expected, with the oldest notes being taken-out, and the newest notes sounding the proper direction of the glissando. My device has 84 keys, but I used only the white keys, so each glissando was 48 notes.

So the results of my testing, other than finding I could not configure-away the bug that affects me in 1.1.5, were not conclusive. It sounded the same as with the defaults, as far as I could tell.

I do encounter the bug using just my keyboard, though I have to work hard to encounter it.


reply via email to

[Prev in Thread] Current Thread [Next in Thread]