Initial working version

2022-12-22 20:22:22 +11:00
parent ce9675a1cc
commit ced7fa5092
902 changed files with 150252 additions and 0 deletions
@@ -0,0 +1,70 @@
+"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 '<id>':
+            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;