I/O Blocks

I/O blocks handle audio input and output for graphs.

Available I/O Blocks

Block Roles

Source (FileInputBlock)

Provides audio from external files:

#![allow(unused)]
fn main() {
use bbx_dsp::blocks::FileInputBlock;

let reader = WavFileReader::from_path("input.wav")?;
let input = builder.add(FileInputBlock::new(Box::new(reader)));
}

Sink (FileOutputBlock)

Writes audio to external files:

#![allow(unused)]
fn main() {
use bbx_dsp::blocks::FileOutputBlock;

let writer = WavFileWriter::new("output.wav", 44100.0, 2)?;
let output = builder.add(FileOutputBlock::new(Box::new(writer)));
}

Terminal (OutputBlock)

Collects audio for real-time output or further processing:

#![allow(unused)]
fn main() {
// Automatically added by GraphBuilder when building
let graph = builder.build();
// Output is collected via process_buffers()
}

Usage Patterns

File Processing

#![allow(unused)]
fn main() {
use bbx_dsp::{
    blocks::{FileInputBlock, FileOutputBlock, GainBlock},
    graph::GraphBuilder,
};
use bbx_file::{readers::wav::WavFileReader, writers::wav::WavFileWriter};

// Set up I/O
let reader = WavFileReader::from_path("input.wav")?;
let writer = WavFileWriter::new("output.wav", 44100.0, 2)?;

let mut builder = GraphBuilder::<f32>::new(44100.0, 512, 2);

// Create graph: Input -> Effect -> Output
let file_in = builder.add(FileInputBlock::new(Box::new(reader)));
let gain = builder.add(GainBlock::new(-6.0, None));
let file_out = builder.add(FileOutputBlock::new(Box::new(writer)));

builder.connect(file_in, 0, gain, 0);
builder.connect(gain, 0, file_out, 0);

let mut graph = builder.build();

// Process entire file
loop {
    let mut left = vec![0.0f32; 512];
    let mut right = vec![0.0f32; 512];
    let mut outputs: [&mut [f32]; 2] = [&mut left, &mut right];
    graph.process_buffers(&mut outputs);

    // Check for end of file...
}

// Finalize output file
graph.finalize();
}

Real-Time Processing

For real-time (plugin, live), use OutputBlock implicitly:

#![allow(unused)]
fn main() {
use bbx_dsp::{blocks::OscillatorBlock, graph::GraphBuilder, waveform::Waveform};

let mut builder = GraphBuilder::<f32>::new(44100.0, 512, 2);

let osc = builder.add(OscillatorBlock::new(440.0, Waveform::Sine, None));
// OutputBlock added automatically

let mut graph = builder.build();

// Audio callback
fn process(graph: &mut Graph, output: &mut AudioBuffer) {
    graph.process_buffers(&mut output.channels());
}
}