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Question: I'm writing a synth in C using portaudio, I am generating sounds via both mathematical functions and hardcoded waveforms, it is great fun! However I get a lot of clicks and pops while playing it (I have midi support), any tips to remedy that?
Asked by Anastasis (94.67.83.x) on November 23 2023, 3:26pm
Reply on November 24 2023, 8:17pm:

Is it in the generated output or is it due to audio device underruns? If the latter, make sure nothing you're doing spends too much time -- if you're generating 10ms of audio, you shouldn't go above 10ms of CPU time (or ideally, nowhere near 10ms of CPU time). And if you have to take a lock, make sure no other thread holds that lock for very long.

Comments:

Posted by Anastasis (94.67.83.x) on November 24 2023, 9:19pm:
It's not underruns, I have very simple sample generation so it's pretty fast, it's actually in the generated output. I tried smoothening every value change possible to remove and sudden "voltage" changes in the wave but I still get clicks and pops
Posted by Gio (94.65.207.x) on November 25 2023, 1:16pm:
@Anastasis: maybe when you use Pa_OpenStream you could try to test framesPerBuffer with paFramesPerBufferUnspecified and also you could check PaStreamFlags like paDitherOff, paClipOff to see if it makes any difference.
Posted by Justin on November 25 2023, 9:44pm:
You definitely need to ramp things when you turn something on or off (or adjust the volume of a signal) in response to an event... any discontinuity will be a click!

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