music-metadata/lib/lyrics3/Lyrics3.js

Music metadata parser for Node.js, supporting virtual any audio and tag format.

import { textDecode } from '@borewit/text-codec';
export const endTag2 = 'LYRICS200';
export async function getLyricsHeaderLength(tokenizer) {
    const fileSize = tokenizer.fileInfo.size;
    if (fileSize >= 143) {
        const buf = new Uint8Array(15);
        const position = tokenizer.position;
        await tokenizer.readBuffer(buf, { position: fileSize - 143 });
        tokenizer.setPosition(position); // Restore position
        const txt = textDecode(buf, 'latin1');
        const tag = txt.substring(6);
        if (tag === endTag2) {
            return Number.parseInt(txt.substring(0, 6), 10) + 15;
        }
    }
    return 0;
}