Utilities

Traversing boxes

The traverseIsoBoxes function traverses box iterators and returns a generator of boxes. It takes an iterable of boxes and two optional arguments: depth-first traversal and maximum depth. By default, the function traverses depth-first with a maximum depth of infinity. A maximum depth of 0 traverses only the root boxes.

import { readIsoBoxes, traverseIsoBoxes } from "@svta/cml-iso-bmff";

const boxes = readIsoBoxes(buffer);

for (const box of traverseIsoBoxes(boxes)) {
	console.log(box.type);
}

Type guards

The library provides type guards that check whether a box is a container box or a full box. These guards narrow the type of a box in TypeScript.

isContainer checks whether a box is a container box.

import { isContainer, type IsoBox } from "@svta/cml-iso-bmff";

const box: IsoBox = { type: "meta", version: 0, flags: 0, boxes: [] };
const container = isContainer(box);

isFullBox checks whether a box is a full box.

import { isFullBox } from "@svta/cml-iso-bmff";

const box = { type: "meta", version: 1, flags: 0 };
const fullBox = isFullBox(box);