/**
 * Port of xa.beat.beat_track()
 * Much faster and more accurate than our basic BPM detector
 */
export function beatTrack(audioData: any, sampleRate: any, { hopLength, startBpm, tightness, _trim, units, }?: {
    hopLength?: number;
    startBpm?: number;
    tightness?: number;
    _trim?: boolean;
    units?: string;
}): {
    tempo: number;
    beats: number[];
    beatFrames: number[];
    onsetStrength: Float32Array<any>;
    confidence: number;
};
/**
 * Fast tempo estimation using autocorrelation
 * Much more efficient than testing every possible BPM
 */
export function estimateTempo(onsetStrength: any, sampleRate: any, hopLength?: number, startBpm?: number): {
    bpm: number;
    confidence: number;
    allCandidates?: undefined;
} | {
    bpm: number;
    confidence: number;
    allCandidates: {
        bpm: number;
        strength: number;
        lag: number;
    }[];
};
/**
 * Dynamic programming beat tracker
 * Simplified version of xa's beat tracking
 */
export function trackBeats(onsetStrength: any, bpm: any, sampleRate: any, hopLength?: number, tightness?: number): number[];
/**
 * Extract tempo from beat times
 * Useful for validation and multiple tempo detection
 */
export function extractTempo(beatTimes: any): {
    bpm: number;
    confidence: number;
    intervals: number[];
    medianInterval: number;
};
/**
 * Optimized BPM detection - replacement for the slow one
 * Uses onset detection + tempo estimation
 *
 * Failure paths THROW with diagnostics naming the failed stage — there is no
 * silent fallback estimator here. (The old catch-all fell back to an
 * RMS-interval heuristic that clamped into [60, 200] BPM and reported a
 * fabricated confidence of 0.5; that path was deleted, 2026-07-04.)
 *
 * @throws {Error} when the beat-tracking stage fails; the original error is
 *   attached as `cause`.
 */
export function fastBPMDetect(audioData: any, sampleRate: any): {
    bpm: number;
    confidence: number;
    beats: number[];
    onsetStrength: Float32Array<any>;
};