/**
 * Pitch-based audio compression — a plain linear-interpolation resample kept
 * at the original sample rate, so PITCH AND TEMPO CHANGE TOGETHER (like
 * playing a record at the wrong speed). No anti-aliasing filter is applied.
 * Use tempoBasedCompress for pitch-preserving tempo change.
 *
 * @param {AudioBuffer} audioBuffer - Input audio buffer
 * @param {number} ratio - Length ratio (0.8 = 20% shorter, faster AND higher-pitched)
 * @returns {Promise<AudioBuffer>} Compressed audio buffer
 */
export function pitchBasedCompress(audioBuffer: AudioBuffer, ratio: number): Promise<AudioBuffer>;
/**
 * Tempo-based audio compression — PITCH-PRESERVING time stretch via the
 * phase vocoder (src/effects/index.js time_stretch). Each
 * channel is stretched independently; output length is
 * round(input length * ratio) and the dominant pitch is unchanged.
 *
 * @param {AudioBuffer} audioBuffer - Input audio buffer
 * @param {number} ratio - Length ratio (0.8 = 20% shorter/faster, same pitch)
 * @returns {Promise<AudioBuffer>} Compressed audio buffer
 */
export function tempoBasedCompress(audioBuffer: AudioBuffer, ratio: number): Promise<AudioBuffer>;