Module buffer 

Audio buffer abstractions for plugin processing.

This module provides Buffer for main audio I/O and AuxiliaryBuffers for sidechain and auxiliary bus access.

Architecture

Audio processing in Beamer uses two separate buffer types:

• Buffer: Main stereo/surround I/O - used by all plugins
• AuxiliaryBuffers: Sidechain and aux buses - used by multi-bus plugins

This separation solves Rust’s lifetime variance constraints with nested mutable references while providing a clean, ergonomic API.

Real-Time Safety

All buffer types use fixed-size stack storage with no heap allocations. This guarantees real-time safety in audio processing callbacks.

Generic Sample Type

All buffer types are generic over S: Sample, defaulting to f32. This enables zero-cost generic processing for both 32-bit and 64-bit audio.

Example: Simple Gain Plugin

fn process(&mut self, buffer: &mut Buffer, _aux: &mut AuxiliaryBuffers) {
    let gain = self.params.gain();
    for (input, output) in buffer.zip_channels() {
        for (i, o) in input.iter().zip(output.iter_mut()) {
            *o = *i * gain;
        }
    }
}

Example: Sidechain Compressor

fn process(&mut self, buffer: &mut Buffer, aux: &mut AuxiliaryBuffers) {
    // Analyze sidechain input
    let key_level = aux.sidechain()
        .map(|sc| sc.rms(0))  // RMS of first channel
        .unwrap_or(0.0);

    // Apply compression based on sidechain
    let reduction = self.compute_gain_reduction(key_level);
    for output in buffer.outputs_mut() {
        for sample in output {
            *sample *= reduction;
        }
    }
}

Structs

AuxInput

Immutable view of an auxiliary input bus.

AuxOutput

Mutable view of an auxiliary output bus.

AuxiliaryBuffers

Auxiliary audio buffers for sidechain and multi-bus processing.

Buffer

Main audio buffer for plugin processing.

Type Aliases

AudioBufferDeprecated

DEPRECATED: Use Buffer and AuxiliaryBuffers instead.

BusDeprecated

DEPRECATED: Use AuxInput or AuxOutput instead.