/**
 * MP3 inspection without decoding.
 *
 * Reading an MP3's duration, bitrate, and channel layout does not require
 * decoding a single sample — the information is in the frame headers and the
 * Xing/VBRI tag. That makes probing effectively free even for a large file,
 * which is what you want for an upload validator, a media library scan, or a
 * "reject anything over 10 minutes" check.
 *
 * Duration is exact for CBR and for VBR files carrying a frame count. For a VBR
 * file with no tag, every frame header is walked — still far cheaper than
 * decoding, and the result is exact rather than the extrapolated guess most
 * tools return.
 */
import { type ChannelMode, type MpegVersion } from './frame.js';
export interface Mp3Info {
    /** Duration in seconds. */
    duration: number;
    sampleRate: number;
    channels: number;
    channelMode: ChannelMode;
    /** Average bitrate in bits per second. */
    bitrate: number;
    /** True when the file uses variable bitrate. */
    vbr: boolean;
    mpegVersion: MpegVersion;
    layer: number;
    /** Total MPEG frames. */
    frameCount: number;
    /** Byte offset of the first audio frame, past any ID3v2 tag. */
    audioOffset: number;
    /** Encoder delay in samples, when a LAME tag declares it. */
    encoderDelay?: number;
    /** Encoder padding in samples, when a LAME tag declares it. */
    encoderPadding?: number;
}
/**
 * Reads an MP3's properties without decoding it.
 *
 * @param scanAll When a VBR file has no frame-count tag, walk every frame for an
 * exact duration. Defaults to `true`; set `false` to estimate from the first
 * frame instead, which is much faster but wrong for VBR.
 */
export declare function probeMp3(input: Uint8Array, scanAll?: boolean): Mp3Info;