vst3_host_test/
vst3_host_test.rs

1//! Manual verification example for the VST3 host: scans a real VST3
2//! directory, loads one plugin, and pushes a block of audio through it.
3//!
4//! Run with: cargo run --example vst3_host_test --features vst3
5
6use std::path::Path;
7
8use mkaudiolibrary::host::{load, scan_vst3};
9use mkaudiolibrary::processor::AudioIO;
10
11fn main() {
12    let dir = Path::new("/Library/Audio/Plug-Ins/VST3");
13    let found = scan_vst3(dir);
14    println!("Found {} VST3 classes in {}", found.len(), dir.display());
15    for d in found.iter().take(8) {
16        println!("  [{}] {} - {}", d.format, d.vendor, d.name);
17    }
18
19    let descriptor = found
20        .first()
21        .expect("no VST3 plugins found to test against");
22    println!("\nLoading: {} - {}", descriptor.vendor, descriptor.name);
23
24    let mut plugin = load(descriptor).expect("failed to load VST3 plugin");
25    println!(
26        "Loaded '{}' by '{}': {} in / {} out, {} parameters",
27        plugin.name(),
28        plugin.vendor(),
29        plugin.num_inputs(),
30        plugin.num_outputs(),
31        plugin.num_parameters()
32    );
33
34    plugin.prepare(48000, 512).expect("prepare failed");
35    plugin.set_active(true).expect("set_active failed");
36
37    for i in 0..plugin.num_parameters().min(5) {
38        println!(
39            "  param[{}] '{}' = {:.4}",
40            i,
41            plugin.parameter_name(i),
42            plugin.get_parameter(i)
43        );
44    }
45
46    let in_channels = plugin.num_inputs().max(1);
47    let out_channels = plugin.num_outputs().max(1);
48
49    // AudioIO borrows into caller-owned storage rather than allocating its
50    // own - own the actual sample memory here, for the life of this block.
51    let mut input_storage = vec![vec![0.0f32; 512]; in_channels];
52    let mut output_storage = vec![vec![0.0f32; 512]; out_channels];
53
54    for channel in &mut input_storage {
55        for (i, sample) in channel.iter_mut().enumerate() {
56            *sample = (i as f32 / 48000.0 * 440.0 * std::f32::consts::TAU).sin() * 0.25;
57        }
58    }
59
60    let input: Vec<&[f32]> = input_storage.iter().map(Vec::as_slice).collect();
61    let mut output: Vec<&mut [f32]> = output_storage.iter_mut().map(Vec::as_mut_slice).collect();
62    let mut audio = AudioIO::new(Some(&input), &mut output, None, None);
63
64    plugin.process(&mut audio);
65
66    let mut peak = 0.0f32;
67    let mut nonzero = false;
68    for channel in &output_storage {
69        for &s in channel.iter() {
70            if s != 0.0 {
71                nonzero = true;
72            }
73            peak = peak.max(s.abs());
74        }
75    }
76
77    println!("\nOutput peak: {:.6}, nonzero: {}", peak, nonzero);
78    println!(
79        "OK: VST3 host rendered a real block of audio through '{}'.",
80        plugin.name()
81    );
82}
vst3_host_test/vst3_host_test.rs

vst3_host_test/
vst3_host_test.rs
