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by onli 1961 days ago
Hey, thanks for building this! There are multiple options like this for Pulseaudio, but last I researched it nothing for pure ALSA. On a system without Pulseaudio this is obviously better, great to have.

The pulseaudio plugins like noisetorch have the issue of significant system load even without current sound input (something about how the loopback works iirc), will this alsa plugin share that issue or will the system load be lower when currently there is no sound input?
2 comments
ArsenArsen 1961 days ago
The plugin uses very little CPU, and is entirely inactive when not in use (i.e. when data isn't being pulled => the transfer function isn't being called) due to how ALSA works

EDIT: Do note, though, that each process pulling audio will be denoising independently, so the usage scales linearly with the amount of clients. This is due to how ALSA plugins work, but regardless of that, on a Ryzen 5 1600x (the only CPU I can test on), the plugin uses 2.5% of a single core when recording mono 48k

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onli 1961 days ago
Excellent.

I'm testing this right now and am noticing that some more info about the installation could be helpful. Specifically, when installing rnnoise as shown in the readme it of course goes to /usr/local/lib, but /usr/local/lib/pkgconfig was not in the PKG_CONFIG_PATH of my distro. Maybe there could be a hint to set that when calling `meson build` if rnnoise can't be found?

Packaging software is always annoying, sorry for dragging you into that mud. Ideally distros will pick it up and compiling manually unnecessary. I would have left this as an issue but saw no issue tracker on the project page.

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ArsenArsen 1961 days ago
There's an issue tracker on that page, under tickets, but I'd prefer if you took a discussion to the attached mailing list first before it hits the official tracker.

As for packaging, that's my field of work for some projects I'm working on so it's not unfamiliar to me, the only problem is that the RNNoise upstream lacks releases, although there's discussion about something happening about that.

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onli 1961 days ago
Okay. To also mention the result: Installation worked, alsa plugin worked and the filter does work. Nice, thanks again.

With extreme sounds (vacuum) in the background the voice gets a bit more distorted than ideal, but something like a keyboard gets filtered nicely to be less noisy. I assumed that's just how RNNoise behaves, I'm just mentioning it because of the sound quality discussion above. Maybe also to that: Just activating the alsa_rnnoise filter does not significantly lower recording quality, at least not that I can notice.

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darkwater 1961 days ago
> There are multiple options like this for Pulseaudio,

Mind sharing? I didn't manage to find any that was easy to install/configure, so it would help me a lot. Thanks!

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onli 1961 days ago
NoiseTorch is the one I use on my Pulseaudio-enabled laptop, https://github.com/lawl/NoiseTorch. It has a GUI and is very easy to install, seems to work well. Significant cpu usage when active, so I only load it when it's needed, but that's okay for me.
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