Sound glitch at end of stream

I found that, occasionally (4/10 times), a crack could be heard when the stream was closed. I was able to resolve this (0/10 tries) by writing a frame of zeros before calling sd.CallbackStop.

I was writing sine waves with a fade out and recording the resulting sound. Here is an example of the cracking sound. Data sent to outdata is shown (top track) against the recorded sound (bottom track). They have only been aligned by eye.

It seems that a solution was to write a frame of all zeros: outdata[:] = [[0,0]] * samples

And then in the next call of the callback: raise sd.CallbackStop

Operating system: macOS 10.13.6 PortAudio version: PortAudio V19.6.0-devel (installed via brew)

I hope that’s helpful to someone else.

Cheers,

Matthew

[mgeier]

Thanks for the update! That’s good news!

I’d like to keep this issue open for now as a reminder to make this problem more visible in the docs.

I think this should be at least mentioned in the documentation of the CallbackStop and CallbackAbort exceptions.

Any other ideas for improving the docs?

As always, I’m open for PRs …

[mattgwwalker]

I have been looking out for this issue for the last two weeks and actively filling the buffer with zeros seems to be the solution.

I think this issue can be closed.

Cheers,

Matthew