/**
 * Mel spectrogram with a (y, options) API.
 * Thin wrapper over the validated scripts/xa-mel.js implementation.
 * @param {Float32Array|Array|null} y - time series (or null when S given)
 * @param {Object} options - { sr, S, n_fft, hop_length, win_length, window,
 *   center, pad_mode, power, n_mels, fmin, fmax, norm, htk }
 * @returns {Array<Float32Array>} [n_mels][n_frames]
 */
export function melspectrogram(y?: Float32Array | any[] | null, options?: any): Array<Float32Array>;
/**
 * Mel-frequency cepstral coefficients.
 * @param {Float32Array|Array|null} y - time series (or null when S given)
 * @param {Object} [options]
 * @param {number} [options.sr=22050] - sample rate (forwarded to melspectrogram)
 * @param {Array|null} [options.S=null] - precomputed LOG-power mel spectrogram
 *   (pass power_to_db(melspectrogram(...)))
 * @param {number} [options.n_mfcc=20] - number of coefficients
 * @param {number} [options.dct_type=2] - only type 2 is implemented
 * @param {string|null} [options.norm='ortho'] - DCT normalization: 'ortho' or null
 * @param {number} [options.lifter=0] - cepstral liftering parameter
 * @param {string|number|null} [options.mel_norm='slaney'] - mel filterbank
 *   normalization forwarded to melspectrogram as `norm`
 * Remaining options forward to melspectrogram (sr, n_fft, hop_length, n_mels, ...).
 * @returns {Array<Float64Array>} [n_mfcc][n_frames]
 */
export function mfcc(y?: Float32Array | any[] | null, options?: {
    sr?: number;
    S?: any[] | null;
    n_mfcc?: number;
    dct_type?: number;
    norm?: string | null;
    lifter?: number;
    mel_norm?: string | number | null;
}): Array<Float64Array>;
export { dctBasis, mfccFromLogMel } from "./dct.js";