rodio/examples/automatic_gain_control.rs

use rodio::source::Source;
use rodio::Decoder;
use std::fs::File;
use std::io::BufReader;
use std::sync::atomic::{AtomicBool, Ordering};
use std::sync::Arc;
use std::thread;
use std::time::Duration;

fn main() {
    let (_stream, handle) = rodio::OutputStream::try_default().unwrap();
    let sink = rodio::Sink::try_new(&handle).unwrap();

    // Decode the sound file into a source
    let file = BufReader::new(File::open("assets/music.flac").unwrap());
    let source = Decoder::new(file).unwrap();

    // Apply automatic gain control to the source
    let agc_source = source.automatic_gain_control(1.0, 4.0, 0.005, 5.0);

    // Make it so that the source checks if automatic gain control should be
    // enabled or disabled every 5 milliseconds. We must clone `agc_enabled`,
    // or we would lose it when we move it into the periodic access.
    let agc_enabled = Arc::new(AtomicBool::new(true));

    #[cfg(not(feature = "experimental"))]
    {
        let agc_enabled_clone = agc_enabled.clone();
        let controlled = agc_source.periodic_access(Duration::from_millis(5), move |agc_source| {
            agc_source.set_enabled(agc_enabled_clone.load(Ordering::Relaxed));
        });

        // Add the source now equipped with automatic gain control and controlled via
        // periodic_access to the sink for playback.
        sink.append(controlled);
    }
    #[cfg(feature = "experimental")]
    {
        sink.append(agc_source);
    }

    // After 5 seconds of playback disable automatic gain control using the
    // shared AtomicBool `agc_enabled`. You could do this from another part
    // of the program since `agc_enabled` is of type Arc<AtomicBool> which
    // is freely clone-able and move-able.
    //
    // Note that disabling the AGC takes up to 5 millis because periodic_access
    // controls the source every 5 millis.
    thread::sleep(Duration::from_secs(5));
    agc_enabled.store(false, Ordering::Relaxed);

    // Keep the program running until playback is complete
    sink.sleep_until_end();
}