hound VS rust-sdl2

One of the simplest encodings would be WAV, for which the crate hound exists (it's linked from rodio's README): https://github.com/ruuda/hound/blob/master/examples/append.rs

I'm no expert when it comes to audio, but this works and is basically copied from the readme.md in hound's repository, along an utility trait that adds ringbuffer-like behavior to VecDeque. How does decoding Opus come into play here?

To load the audio data from file you need a separate library, e.g. hound for .wav files.

I don't think that SDL and WGPU are really comparable. You'd be better off comparing SDL to something like Notan or even the SDL bindings for Rust. That said, SDL will have vastly more learning resources than Wgpu or Notan or any Rust alternative. If you know and like rust you can probably use the resources with the Rust SDL bindings.

Those are 3 very different libraries. Are you looking for something in the middle, or do you want all of the features you described? For what it's worth, there's SLD2 bindings for Rust https://github.com/Rust-SDL2/rust-sdl2

There's already a Rust binding for SDL2. See https://crates.io/crates/sdl2

nope. https://github.com/Rust-SDL2/rust-sdl2/issues/884 emscripten target won't work yet either.

it seems like what you are looking for is sdl2 bindings

Dude. It's literally at most 50 lines of code, the entire project. What kind of documentation do you expect me to write? The library I'm using is this one. I don't know why you'd need to know anything about it since it's purely something that can appear literally anywhere, it's part of the language.

*and* SDL2-sys *and* Rust-SDL2

The SDL2 crate had something like this, and it's an option I'm considering. However, if possible, I'd prefer a different, simpler GUI library, so if there's an input-specialized crate out there that does this, I'd love it.