rill-io

Audio I/O backends — ALSA, CPAL, PipeWire, JACK.

This crate provides I/O backends and the AudioInput/AudioOutput graph nodes that own the reactive stream (PipeWire callback or similar).

All backends implement [AudioIo] — a trait for reactive stream processing: set_process_callback, read_input, write_output, start, stop.

Nodes

• AudioInput — Source node (push model). Owns the backend (Box<dyn AudioIo>). Creates the process callback via [start()]. Backend can be created externally via [set_backend()] or by name via [init_backend()].

  let mut input = AudioInput::<f32, 256>::new();
  input.init_backend("pipewire", config)?;
  input.start(nodes_ptr, source_idx, drain_fn, sample_rate);
  

• AudioOutput — Sink node (push model or pull model). Borrows backend via [AudioIoPtr]. In pull model, [set_active()] stores the source index and [start()] drives the graph from that source:

  let mut output = AudioOutput::<f32, 256>::new();
  output.set_backend(ptr);
  output.set_active(source_idx);
  output.start(nodes_ptr, drain_fn, sample_rate);
  

Processing models

In both cases the callback does:

1. Drain MpscQueue<ParameterCommand> into graph nodes
2. process_block() on the source → generate() fills output ports
3. Port::propagate() — recursive DAG traversal, data lands in port buffers
4. AudioOutput::consume() reads from its input ports → write_output()

Backends

Links

• Repository: https://github.com/DigitalRats/rill
• Documentation: https://docs.rs/rill-io