/**
 * Structural edits: cutting, joining, padding, reversing, and mixing.
 *
 * Every function here takes and returns planar channel arrays and allocates a
 * fresh result. Nothing mutates its input — an editing pipeline that mutates in
 * place makes `const original = ...` a lie, and undo impossible.
 */
/** Extracts frames `[start, end)` from every channel. */
export declare function slicePlanar(channels: readonly Float32Array[], start: number, end: number): Float32Array[];
/** Removes frames `[start, end)`, joining what remains. */
export declare function removeRange(channels: readonly Float32Array[], start: number, end: number): Float32Array[];
/**
 * Concatenates buffers end to end.
 *
 * All inputs must already agree on channel count — this operates on raw sample
 * data and has no sample rate to reconcile. The `Audio` wrapper checks rates
 * before delegating here.
 */
export declare function concatPlanar(buffers: ReadonlyArray<readonly Float32Array[]>): Float32Array[];
/** Adds silence before and/or after. */
export declare function padPlanar(channels: readonly Float32Array[], before: number, after: number): Float32Array[];
/** Reverses every channel in place-equivalent fashion, returning new arrays. */
export declare function reversePlanar(channels: readonly Float32Array[]): Float32Array[];
export interface MixOptions {
    /** Frame at which the overlaid buffer starts. Defaults to 0. */
    offset?: number;
    /** Linear gain applied to the overlaid buffer. Defaults to 1. */
    gain?: number;
    /**
     * Extend the result when the overlay runs past the end. Defaults to `false`,
     * which truncates to the original length.
     */
    extend?: boolean;
}
/**
 * Sums `overlay` onto `base`.
 *
 * Summing can exceed ±1. Nothing is clamped here — clipping is a decision for
 * the point where audio leaves the float domain, and clamping early would
 * silently destroy headroom that a later `normalize` could have recovered.
 */
export declare function mixPlanar(base: readonly Float32Array[], overlay: readonly Float32Array[], options?: MixOptions): Float32Array[];