"use strict"; Object.defineProperty(exports, "__esModule", { value: true }); exports.Atom = void 0; const initDebug = require("debug"); const AtomToken = require("./AtomToken"); const debug = initDebug('music-metadata:parser:MP4:Atom'); class Atom { constructor(header, extended, parent) { this.header = header; this.extended = extended; this.parent = parent; this.children = []; this.atomPath = (this.parent ? this.parent.atomPath + '.' : '') + this.header.name; } static async readAtom(tokenizer, dataHandler, parent, remaining) { // Parse atom header const offset = tokenizer.position; // debug(`Reading next token on offset=${offset}...`); // buf.toString('ascii') const header = await tokenizer.readToken(AtomToken.Header); const extended = header.length === BigInt(1); if (extended) { header.length = await tokenizer.readToken(AtomToken.ExtendedSize); } const atomBean = new Atom(header, header.length === BigInt(1), parent); const payloadLength = atomBean.getPayloadLength(remaining); debug(`parse atom name=${atomBean.atomPath}, extended=${atomBean.extended}, offset=${offset}, len=${atomBean.header.length}`); // buf.toString('ascii') await atomBean.readData(tokenizer, dataHandler, payloadLength); return atomBean; } getHeaderLength() { return this.extended ? 16 : 8; } getPayloadLength(remaining) { return (this.header.length === BigInt(0) ? remaining : Number(this.header.length)) - this.getHeaderLength(); } async readAtoms(tokenizer, dataHandler, size) { while (size > 0) { const atomBean = await Atom.readAtom(tokenizer, dataHandler, this, size); this.children.push(atomBean); size -= atomBean.header.length === BigInt(0) ? size : Number(atomBean.header.length); } } async readData(tokenizer, dataHandler, remaining) { switch (this.header.name) { // "Container" atoms, contains nested atoms case 'moov': // The Movie Atom: contains other atoms case 'udta': // User defined atom case 'trak': case 'mdia': // Media atom case 'minf': // Media Information Atom case 'stbl': // The Sample Table Atom case '': case 'ilst': case 'tref': return this.readAtoms(tokenizer, dataHandler, this.getPayloadLength(remaining)); case 'meta': // Metadata Atom, ref: https://developer.apple.com/library/content/documentation/QuickTime/QTFF/Metadata/Metadata.html#//apple_ref/doc/uid/TP40000939-CH1-SW8 // meta has 4 bytes of padding, ignore await tokenizer.ignore(4); return this.readAtoms(tokenizer, dataHandler, this.getPayloadLength(remaining) - 4); case 'mdhd': // Media header atom case 'mvhd': // 'movie' => 'mvhd': movie header atom; child of Movie Atom case 'tkhd': case 'stsz': case 'mdat': default: return dataHandler(this, remaining); } } } exports.Atom = Atom;