/** @format */
import { MemoryImage } from '../image/image.js';
import { Decoder, DecoderDecodeOptions } from './decoder.js';
import { ImageFormat } from './image-format.js';
import { PvrAppleInfo } from './pvr/pvr-apple-info.js';
import { Pvr2Info } from './pvr/pvr2-info.js';
import { Pvr3Info } from './pvr/pvr3-info.js';
/**
 * Ported from Jeffrey Lim's PVRTC encoder/decoder,
 * https://bitbucket.org/jthlim/pvrtccompressor
 */
export declare class PvrDecoder implements Decoder {
    /**
     * Size of the PVR header.
     */
    private static readonly pvrHeaderSize;
    /**
     * The data to be decoded.
     */
    private _data;
    /**
     * Information about the decoded data.
     */
    private _info;
    /**
     * Gets the image format.
     */
    get format(): ImageFormat;
    /**
     * Gets the number of frames.
     */
    get numFrames(): number;
    /**
     * Decodes the PVR3 header.
     * @param {Uint8Array} bytes - The byte array containing the header.
     * @returns {Pvr3Info | undefined} The decoded PVR3 information or undefined if invalid.
     */
    private decodePvr3Header;
    /**
     * Decodes the PVR2 header.
     * @param {Uint8Array} bytes - The byte array containing the header.
     * @returns {Pvr2Info | undefined} The decoded PVR2 information or undefined if invalid.
     */
    private decodePvr2Header;
    /**
     * Decodes the Apple PVRTC header.
     * @param {Uint8Array} bytes - The byte array containing the header.
     * @returns {PvrAppleInfo | undefined} The decoded Apple PVRTC information or undefined if invalid.
     */
    private decodeApplePvrtcHeader;
    /**
     * Decodes the PVR2 data.
     * @param {Uint8Array} data - The byte array containing the data.
     * @returns {MemoryImage | undefined} The decoded MemoryImage or undefined if invalid.
     */
    private decodePvr2;
    /**
     * Decodes the PVR3 data.
     * @param {Uint8Array} data - The byte array containing the data.
     * @returns {MemoryImage | undefined} The decoded MemoryImage or undefined if invalid.
     */
    private decodePvr3;
    /**
     * Counts the number of bits set to 1 in the binary representation of a number.
     * @param {number} x - The number to count bits in.
     * @returns {number} The number of bits set to 1.
     */
    private countBits;
    /**
     * Decodes a 4bpp RGB image.
     * @param {number} width - The width of the image.
     * @param {number} height - The height of the image.
     * @param {TypedArray} data - The image data.
     * @returns {MemoryImage} The decoded MemoryImage.
     */
    private decodeRgb4bpp;
    /**
     * Decodes a 4bpp RGBA image.
     * @param {number} width - The width of the image.
     * @param {number} height - The height of the image.
     * @param {TypedArray} data - The image data.
     * @returns {MemoryImage} The decoded MemoryImage.
     */
    private decodeRgba4bpp;
    /**
     * Checks if the given file is valid.
     * @param {Uint8Array} bytes - The file data.
     * @returns {boolean} True if the file is valid, false otherwise.
     */
    isValidFile(bytes: Uint8Array): boolean;
    /**
     * Starts decoding the given file.
     * @param {Uint8Array} bytes - The file data.
     * @returns {PvrAppleInfo | Pvr3Info | Pvr2Info | undefined} The decoded PvrAppleInfo, Pvr3Info, Pvr2Info, or undefined if decoding fails.
     */
    startDecode(bytes: Uint8Array): PvrAppleInfo | Pvr3Info | Pvr2Info | undefined;
    /**
     * Decodes the PVR file into a MemoryImage.
     * @param {DecoderDecodeOptions} opt - The decoding options.
     * @param {Uint8Array} opt.bytes - The file data.
     * @param {number} [opt.frameIndex] - The frame index to decode (optional).
     * @returns {MemoryImage | undefined} The decoded MemoryImage or undefined if decoding fails.
     */
    decode(opt: DecoderDecodeOptions): MemoryImage | undefined;
    /**
     * Decodes a specific frame.
     * @param {number} _frameIndex - The index of the frame to decode.
     * @returns {MemoryImage | undefined} The decoded MemoryImage or undefined if decoding fails.
     */
    decodeFrame(_frameIndex: number): MemoryImage | undefined;
}