mp3tag/out/encoding.js

A library for reading/writing mp3 tag data

"use strict";
/** Encoding module to provide some de-/encoding utilties
 */
Object.defineProperty(exports, "__esModule", { value: true });
exports.encodeUInt7Bit = exports.decodeUInt7Bit = void 0;
/** Decodes a 7bit encoded unsigned integer:
 *  Format: 0b0xxxxxx0xxxxxx0xxxxxx0xxxxxx
 *
 * @param uint28 the number to decode
 *
 * @return the decoded number
 */
function decodeUInt7Bit(uint28) {
    const x = uint28;
    return (x & 0x7F) | ((x & 0x7F00) >> 1) | ((x & 0x7F0000) >> 2) | ((x & 0x7F000000) >> 3);
}
exports.decodeUInt7Bit = decodeUInt7Bit;
/** Encodes a unsigned integer into a  7bit unsigned integer.
 *  The first 4 bits get cut off.
 *
 * @param uint32 the integer to encode
 *
 * @return a 28 bit encoded integer
 */
function encodeUInt7Bit(uint32) {
    const x = uint32;
    return (x & 0x7F) | (((x >> 7) & 0x7F) << 8) | (((x >> 14) & 0x7F) << 16) | (((x >> 21) & 0x7F) << 24);
}
exports.encodeUInt7Bit = encodeUInt7Bit;