bela

Safe Rust API for real-time audio on Bela Gem (PocketBeagle 2, aarch64-unknown-linux-gnu), built on the raw FFI bindings in bela-sys.

User code implements the BelaApplication trait — an unsafe trait, because implementing it is a promise that render is real-time safe — and hands an instance to Bela::run:

use bela::{Bela, BelaApplication, Context, Settings};

struct Passthrough;

unsafe impl BelaApplication for Passthrough {
    fn render(&mut self, context: &mut Context) {
        let channels = context
            .audio_in_channels()
            .min(context.audio_out_channels());
        for frame in 0..context.audio_frames() {
            for channel in 0..channels {
                let sample = context.audio_read(frame, channel);
                context.audio_write(frame, channel, sample);
            }
        }
    }
}

fn main() -> Result<(), bela::Error> {
    Bela::run(Passthrough, &Settings::new())
}

See examples/ for runnable versions and the repository README for project status and cross-compilation instructions.