Function begin 

pub fn begin(config: AnalyzerConfig) -> Result<Receiver<BpmDetection>>

Starts the BPM analyzer with the given configuration using the default device.

This automatically selects an audio input device, preferring BlackHole on macOS, then falling back to the system default input device.

Arguments

• config - The analyzer configuration

Returns

A Receiver that yields BpmDetection results containing up to 5 BPM candidates sorted by confidence (highest first).

Errors

Returns an error if:

• The configuration is invalid
• No suitable audio input device is found
• The audio stream cannot be configured or started
• The device’s sample format is unsupported

Example

use bpm_analyzer::{AnalyzerConfig, begin};

let config = AnalyzerConfig::electronic();
let receiver = begin(config)?;

for detection in receiver.iter() {
    if let Some(bpm) = detection.bpm() {
        println!("Detected BPM: {:.1}", bpm);
    }
}

Examples found in repository

examples/beat_timing.rs (line 16)

fn main() -> Result<(), bpm_analyzer::Error> {
    // Configure the analyzer for electronic music
    let config = AnalyzerConfig::electronic();

    println!("Starting BPM analyzer...");
    println!("Listening for beats and tempo...\n");

    // Start the analyzer
    let receiver = begin(config)?;

    // Process detections
    for detection in receiver.iter() {
        // Print BPM if detected
        if let Some(bpm) = detection.bpm() {
            println!("🎵 Detected BPM: {:.1}", bpm);
        }

        // Print beat timings
        if let Some(last_beat) = detection.last_beat() {
            print!(
                "🥁 Beat at {:.2}s (strength: {:.2})",
                last_beat.time_seconds, last_beat.strength
            );

            // Show beat interval if we have at least 2 beats
            if let Some(interval) = detection.last_beat_interval() {
                let instant_bpm = 60.0 / interval;
                print!(" | Interval: {:.3}s ({:.1} BPM)", interval, instant_bpm);
            }
            println!();
        }

        // Print all recent beat timings
        let beats = detection.beat_timings();
        if beats.len() >= 4 {
            println!("📊 Recent beats: {} detected", beats.len());
            for (i, beat) in beats.iter().rev().take(4).enumerate() {
                println!(
                    "   {} {:.2}s ago (strength: {:.2})",
                    if i == 0 { "•" } else { " " },
                    beats.last().unwrap().time_seconds - beat.time_seconds,
                    beat.strength
                );
            }
        }

        println!();
    }

    Ok(())
}