this is really an information post .
.. as i don't have time to investigate at the moment due to an impending release 🙂

so what Ive noticed is,
if you turn off the dsp processing on pd, and then reactivate it, things go bad 😉

  • the main audio might not sound after reactivation
  • the analog cv in might not behave
  • it sometimes will segv in the main bela_audio thread

what was pretty frustrating, is the inconsistency sometimes it would appear to work,
it 'seemed' to be ok, when buffer size was 16, and crash reliably with 128.

unfortunately its in a pretty complex project, and as I said I don't have time to test to see if its reproducible in a test project at the moment.

basically, what Im doing is disabling with
[; pd dsp 0] , then a bit later enabling with [; pd dsp 1]

Im doing this in an external , but i suspect this is irrelevant.
also Ive got the same thing running on 3 other platforms, and this doesn't cause an issue.
that said, none are using libpd... so the issue might be in the bela pd renderer, or it might be libpd, so some interaction between the two...

for now Im working around on bela/salt by disabling this 'feature' , and all appears ok.

I'll probably follow up after release, as its pretty useful to be able to turn the dsp off, to avoid audio glitches.

Cheers
Mark

I will look into that. Why do you need to disable the DSP temporarily?

Orac 2.0 is coming!

indeed Orac 2.0 is on its way... 🙂

so, Orac dynamically re-patches and PD creates a small audio glitch when you do this whilst audio is being generated
even if you disconnect/mute the audio outputs - but I found if you temporarily stop the dsp, re-patch, then start the dsp , then all is ok .. so thats what I introduced for 2.0.
all was ok, till I realised Salt was crashing unpredictably... and of course, Id forgotten about that particular change... such is life with last minute changes!

I guess creating many objects at onecam cause an underrun in the audio thread, and that may produce an audible noise on some systems. On Bela, an underrun should cause all outputs to go to 0 (although I think on Salt this means that the actual CV outs go to the max value(given how there is an inverting amplifier there), I need to check this, but the audio outs should still be fine) .

So my guess is that if there is a dropout on libpd on Bela, you should hear silence at the
audio outputs, which is the same you d achieve elsewhere by turning off the DSP