Hi Steve, thanks for your reply, but sadly the select-variant does the same thing as the other approaches. Strange though, the jack-reported DSP usage on my PC goes from 12% to about 15% when adding multiple profiles, while the Bela goes from 60% load to not being able to run it at all. Seems like a big load increase, and even increasing the buffer size cannot make it even run. Maybe it's a faust2bela (or Bela-)specific problem...
I think I'll stick with single profiles for now, thanks anyways! Best regards, Robin -----Ursprüngliche Nachricht----- Von: Steve Baker <st...@stevebaker.org> Gesendet: Dienstag 15 Februar 2022 01:30 An: Robin Rosenberger <robin.rosenber...@gmx.de> CC: faudiostream-users@lists.sourceforge.net Betreff: Re: [Faudiostream-users] Possible to change fi.conv impulse response at runtime? I did something similar in a project which generates a complete LV2 plugin from a collection of impulse audio files. The faust does a _ : ba.selectoutn : <many>, <filters>... : ba.selectn : _. I *think* this approach avoids the overhead of running every filter, so only the selected filter is consuming CPU. The project is dormant currently as I don't think the conv implementation is as CPU efficient as modern DFT->multiply->IDFT approaches, and that showed in the performance of the generated plugins. If faust provided an optimized frequency domain implementation of fi.conv I would resurrect this project (I don't have the ability to do it myself). Also if convolution values could come from some kind of loaded table instead of inline values that would make loading different filters much easier :) On Tue, Feb 15, 2022 at 10:47 AM Robin Rosenberger <robin.rosenber...@gmx.de <mailto:robin.rosenber...@gmx.de> > wrote: Hi faust users! This might be a very low-level question, but I've been struggling with this for a long time now, so I hope you might be able to help me out. I'm trying to build a guitar amp simulator in pure faust which is basically using two impulse responses to set the profile _ : fi.conv(pre_ir) : some_amp_stuff : fi.conv(post_ir) : _ In order to utilize different amp profiles I need to change pre_ir and post_ir, which are about a hundred decimal values each, at runtime. I don't want to add any additional control code for portability reasons (should run on different platforms and hardware sooner or later), and because I am not a good programmer in any language but bash and hopefully faust soon ;) Since I could not find a way to change the variables at runtime, I currently use parallel channels to achieve this, so for the convolution gets replaced by this profile_pre = _<:fi.conv(pre_ir_0)*(chan==0) ,fi.conv(pre_ir_1)*(chan==1) ,fi.conv(pre_ir_2)*(chan==2) ,fi.conv(pre_ir_3)*(chan==3) ,fi.conv(pre_ir_4)*(chan==4) ,fi.conv(pre_ir_5)*(chan==5) ,fi.conv(pre_ir_6)*(chan==6) :>_; Alternatively I tried a serial approach, bypassing the unneeded convolutions: profile_pre = ba.bypass1((chan!=0),fi.conv(pre_ir_0)):ba.bypass1((chan!=1),fi.conv(pre_ir_1)); where chan is a variable setting the selected channel, obviously. Both approaches work quite ok on my PC, but both of them seem to actually calculate at least some of the parallel/bypassed filters all the time. Because of that I get higher CPU load when using different profiles, and buffer underruns whenever I try to use it on lower-grade hardware such as Teensy or Bela, which is basically the goal of this project. Single convolution filters work fine on both. Is there a better way of doing this? Really looking forward to any hints! Best regards, Robin Rosenberger _______________________________________________ Faudiostream-users mailing list Faudiostream-users@lists.sourceforge.net <mailto:Faudiostream-users@lists.sourceforge.net> https://lists.sourceforge.net/lists/listinfo/faudiostream-users
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