wasm performance compared to bevy_audio

[shnewto]

Hello! 👋
Thanks for all your work! I really love this crate ❤️ ❤️

I'm creating this issue because I'd like to document some surprising (to me) behavior of bevy_kira_audio / kira in comparison to bevy_audio 😄

Because of some crackling audio in the browser (see #27) I recently ported a project of mine to bevy_audio in a branch to experiment.

After porting I noticed a significant speedup to load times as well as the crackling audio going away.

Anecdotally, when using bevy_kira_audio it takes a couple seconds for my "Play" button to display and then a couple more after clicking "Play" for the scene to render. When I switched to bevy_audio, everything much quicker, i.e. no delay between startup and "Play" button or after clicking "Play".

project code: https://github.com/shnewto/limbo_pass

wasm branches

• wasm-rodio
• wasm-kira

Some of this is definitely a candidate for being system specific, I'm on macOS Monterey 12.3.1. I'd be curious to know if this is or isn't the case for someone with a different setup.

[shnewto]

oof, I'm not sure about the behavior I mentioned above anymore. not sure what I bumped (maybe my head 😅) but my wasm-rodio branch seems to be crackling too and has a delay loading the scene 🤔

[NiklasEi]

Thank you for looking into this!
Let's see if #48 changes anything here. I've had fewer issues with Bevy 0.7 so far, but will investigate again after updating to latest Kira.

[shnewto]

Closing because I've spent some time digging and am convinced the crunchy/crackling audio isn't a kira or bevy_kira_audio issue. It's still there when I use rodio. I did get the behavior to change when I increased a default raw audio buffer size in cpal so that's probably where I'll keep looking. Thanks for your time ❤️

[NiklasEi]

Could you tell me more about the changes in cpal that improved the situation? Maybe this is something that could be made configurable through Kira/rodio?

[shnewto]

@NiklasEi The changes I was experimenting with in cpal were mostly in the build_output_stream_raw function here https://github.com/RustAudio/cpal/blob/223f28262a80ac0b81688eb58507a4fb243e0694/src/host/webaudio/mod.rs#L185.

The crunchy audio while loading made me suspect some buffer underrun so I toggled the configuration buffer size, here https://github.com/RustAudio/cpal/blob/223f28262a80ac0b81688eb58507a4fb243e0694/src/host/webaudio/mod.rs#L202-L211

It does look like kira is building up a cpal config object https://github.com/tesselode/kira/blob/acb99e9e322da95cd91c4529d9a9f520e824ac56/crates/kira/src/manager/backend/cpal/wasm.rs#L51 so it might be feasible to expose it.

Fwiw though, I'm not sure toggling that buffer size is ultimately the fix for my crunchy audio issue because I had to make the buffer a lot bigger and from the documentation it seemed like the main use case is actually making it smaller 😅 .

[shnewto]

if you're curious to see the behavior, it's deployed here https://limbo-pass-shnewto.vercel.app

At the moment, it sits on the title screen for a good few seconds before drawing the scene, I've been experimenting with trying to get things to load before playing the audio but so far haven't resolved the behavior yet