rust-cookbook VS cpal

I'm trying to fix the two test failures in the current master of the Rust Cookbook related to the API change of the rand crate. It went from accepting a couple numbers (in 0.5.6) to a Range instead (in 0.8.0).

rust cookbook

I don't know why he's doing it like this. I thought it might have something to do with the example being around 2 years old, dating back to version 0.14 of the rusqlite crate, but that does not seem to be the case. It could be as simple as the author just not noticing it wasn't required.

debugging this nightmare bc its blocking my hobby project. by far the most fucked up issue ive encountered since i started rust.

There is a cross-platform audio library for Rust: cpal https://github.com/rustaudio/cpal

cpal crate should work fine for this use case, though it might be unnecessarily low-level for your use case.

I had to do something similar to this a while back. I used cpal.

Working on a live performance software that would let our band have live real-time practices over the internet. Top priority is minimum latency, so I'm trying to hook it up through ASIO. Not much luck yet. I've tried cpal, but I've run into numerous known random bugs (and some versions don't compile for me). At least I confirmed that I can push the audio through a TCP socket successfully.

With https://github.com/RustAudio/cpal you can access the microphone in a cross platform way, but you’ll get values of range [-1,1] out only. To calculate absolute decibels you would need to calibrate for your specific microphone with a known source.

source of example

you need to use a "loopback" device, as shown here - https://github.com/RustAudio/cpal/pull/478 (note, ive only tested this on windows - if its not supported on linux you could always plug your sound card output into its line-in/mic jack)