/**
 * Constant-Q Transform of an audio signal (single-pass
 * evaluation — see module header for documented divergences).
 *
 * Legacy positional signature preserved.
 *
 * @param {Float32Array} y - Audio time series
 * @param {number} sr - Sample rate
 * @param {number} hop_length - Samples between successive CQT columns
 * @param {number|null} fmin - Minimum frequency (Hz); defaults to C1
 * @param {number} n_bins - Number of frequency bins
 * @param {number} bins_per_octave - Bins per octave
 * @param {number} tuning - Tuning offset in fractions of a bin
 * @param {number} filter_scale - Filter scale factor
 * @param {number|null} norm - Filter normalization (1, 2, Infinity, or null)
 * @param {number} sparsity - Accepted but not applied (dense basis)
 * @param {string} window - Window function ('hann' only)
 * @param {boolean} scale - Divide by sqrt(filter length) (scale=True)
 * @param {string} pad_mode - Padding mode for signal edges
 * @returns {Array<Array<{real:number, imag:number}>>} CQT [n_bins][n_frames]
 *   with n_frames = 1 + floor(len(y)/hop_length)
 * @throws {Error} on invalid parameters or a filterbank exceeding Nyquist
 */
export function cqt(y: Float32Array, sr?: number, hop_length?: number, fmin?: number | null, n_bins?: number, bins_per_octave?: number, tuning?: number, filter_scale?: number, norm?: number | null, sparsity?: number, window?: string, scale?: boolean, pad_mode?: string): Array<Array<{
    real: number;
    imag: number;
}>>;
/**
 * Variable-Q Transform. intervals='equal' with the default
 * ERB-derived gamma (24.7 * alpha / 0.108); pass gamma=0 to recover cqt().
 * Custom interval arrays build freqs[i] = fmin * 2^floor(i/len) * ratio.
 *
 * @param {Float32Array} y - Audio time series
 * @param {number} sr - Sample rate
 * @param {number} hop_length - Hop length
 * @param {number|null} fmin - Minimum frequency (default C1)
 * @param {number} n_bins - Number of bins
 * @param {string|Array<number>} intervals - 'equal' or interval ratios
 * @param {number|null} gamma - Bandwidth offset (null = ERB default)
 * @param {number} bins_per_octave - Bins per octave for 'equal'
 * @param {number} tuning - Tuning offset in bins
 * @param {number} filter_scale - Filter scale factor
 * @param {number|null} norm - Filter normalization
 * @param {number} sparsity - Accepted but not applied
 * @param {string} window - Window function ('hann' only)
 * @param {boolean} scale - Divide by sqrt(filter length)
 * @param {string} pad_mode - Padding mode
 * @returns {Array<Array<{real:number, imag:number}>>} VQT [n_bins][n_frames]
 */
export function vqt(y: Float32Array, sr?: number, hop_length?: number, fmin?: number | null, n_bins?: number, intervals?: string | Array<number>, gamma?: number | null, bins_per_octave?: number, tuning?: number, filter_scale?: number, norm?: number | null, sparsity?: number, window?: string, scale?: boolean, pad_mode?: string): Array<Array<{
    real: number;
    imag: number;
}>>;
/**
 * Pseudo-CQT: magnitude-only approximation |fft_basis| · |STFT|
 * (pseudo-CQT shape). Returns REAL magnitudes, not complex values.
 *
 * @param {Float32Array} y - Audio time series
 * @param {number} sr - Sample rate
 * @param {number} hop_length - Hop length
 * @param {number|null} fmin - Minimum frequency (default C1)
 * @param {number} n_bins - Number of bins
 * @param {number} bins_per_octave - Bins per octave
 * @param {number} tuning - Tuning offset in bins
 * @param {number} filter_scale - Filter scale
 * @param {number|null} norm - Filter normalization
 * @param {number} sparsity - Accepted but not applied
 * @param {string} window - Window function ('hann' only)
 * @param {boolean} scale - pseudo-CQT scaling (sqrt(n_fft/lengths))
 * @param {string} pad_mode - Padding mode
 * @returns {Array<Float64Array>} magnitude matrix [n_bins][n_frames]
 */
export function pseudo_cqt(y: Float32Array, sr?: number, hop_length?: number, fmin?: number | null, n_bins?: number, bins_per_octave?: number, tuning?: number, filter_scale?: number, norm?: number | null, sparsity?: number, window?: string, scale?: boolean, pad_mode?: string): Array<Float64Array>;
/**
 * Hybrid CQT: pseudo-CQT for the top two octaves stacked over the full CQT
 * for the rest. Returns MAGNITUDES (hybrid-CQT shape).
 *
 * @param {Float32Array} y - Audio time series
 * @param {number} sr - Sample rate
 * @param {number} hop_length - Hop length
 * @param {number|null} fmin - Minimum frequency (default C1)
 * @param {number} n_bins - Number of bins
 * @param {number} bins_per_octave - Bins per octave
 * @param {number} tuning - Tuning offset in bins
 * @param {number} filter_scale - Filter scale
 * @param {number|null} norm - Filter normalization
 * @param {number} sparsity - Accepted but not applied
 * @param {string} window - Window function ('hann' only)
 * @param {boolean} scale - Scaling flag
 * @param {string} pad_mode - Padding mode
 * @returns {Array<Float64Array>} magnitude matrix [n_bins][n_frames]
 */
export function hybrid_cqt(y: Float32Array, sr?: number, hop_length?: number, fmin?: number | null, n_bins?: number, bins_per_octave?: number, tuning?: number, filter_scale?: number, norm?: number | null, sparsity?: number, window?: string, scale?: boolean, pad_mode?: string): Array<Float64Array>;
/**
 * Inverse CQT is NOT implemented. The previous body
 * overlap-added the ANALYSIS wavelets (a correct inverse reconstructs through
 * the dual frame with per-octave resampling) via an O(N^2) DFT loop, producing
 * unusable output. It now fails honestly instead.
 * @throws {Error} always
 */
export function icqt(): void;
/**
 * Griffin-Lim CQT reconstruction depends on icqt and is therefore NOT
 * implemented. Fails honestly. For STFT-magnitude reconstruction use the
 * repaired griffinlim in scripts/xa-advanced.js.
 * @throws {Error} always
 */
export function griffinlim_cqt(): void;