/**
 * Optional WebCodecs acceleration — `audiobox/webcodecs`.
 *
 * ## Why this is optional, and only an accelerator
 *
 * WebCodecs gives browsers hardware-accelerated access to codecs the platform
 * already ships — notably Opus and AAC, which audiobox does not implement. It
 * is tempting to build a library on top of it. That does not work for an
 * isomorphic package: **Node has no WebCodecs.** `AudioEncoder`, `AudioDecoder`,
 * and `AudioData` are all undefined there (verified on Node 23; still absent in
 * 24 and 25), and the popular "webcodecs for Node" packages are native FFmpeg
 * bindings — which would mean a dependency, and a heavy one.
 *
 * So the pure-TypeScript path is the real implementation everywhere, and this
 * module is a bonus that lights up when the host provides it. Everything here
 * feature-detects and degrades; nothing in core imports it.
 *
 * Codec availability also varies by browser and cannot be assumed — always check
 * {@link isCodecSupported} rather than trusting a support matrix.
 */
import { Audio } from '../audio.js';
/** True when this runtime exposes the WebCodecs audio interfaces at all. */
export declare function isWebCodecsAvailable(): boolean;
/**
 * Asks the platform whether it can encode a given codec configuration.
 *
 * Returns `false` rather than throwing when WebCodecs is missing entirely, so
 * this can be used directly as a feature check.
 */
export declare function isCodecSupported(codec: string, sampleRate?: number, numberOfChannels?: number): Promise<boolean>;
/** Codec strings worth probing, in rough order of usefulness. */
export declare const COMMON_CODECS: Readonly<{
    /** Opus in a WebM container — the best-supported lossy option on the web. */
    opus: "opus";
    /** AAC-LC. Widely supported for playback; encode support varies. */
    aac: "mp4a.40.2";
    /** FLAC via the platform, when you would rather not ship our encoder. */
    flac: "flac";
    /** G.711 companding, for telephony pipelines. */
    alaw: "alaw";
    ulaw: "ulaw";
}>;
export interface WebCodecsEncodeOptions {
    /** Codec string, e.g. `'opus'`. See {@link COMMON_CODECS}. */
    codec: string;
    /** Target bitrate in bits per second. */
    bitrate?: number;
    /** Frames per encoded chunk. Defaults to 1024. */
    chunkFrames?: number;
}
/**
 * Encodes audio using the platform's own codec implementation.
 *
 * Returns the raw encoded chunks. They are **not** wrapped in a container — a
 * WebM or MP4 muxer is a separate concern, and pretending otherwise would
 * produce files that do not play.
 *
 * @throws {UnsupportedRuntimeError} when WebCodecs or the codec is unavailable.
 */
export declare function encodeWithWebCodecs(audio: Audio, options: WebCodecsEncodeOptions): Promise<{
    chunks: Uint8Array[];
    totalBytes: number;
}>;