revelo-wasm

WebAssembly bindings for revelo — parse media metadata in the browser with no server round-trip.

Pass a file buffer from JavaScript, get MediaInfo-style JSON back. Pure Rust under the hood; no native dependencies at runtime.

Install

npm install revelo-wasm

Quick start

import init, { parse, version } from "revelo-wasm";

await init();

console.log(version()); // e.g. "0.5.1"

const input = document.querySelector('input[type="file"]');
input.addEventListener("change", async (event) => {
  const file = event.target.files[0];
  const buf = await file.arrayBuffer();
  const json = parse(new Uint8Array(buf));

  if (json === null) {
    console.log("format not recognized");
    return;
  }

  console.log(JSON.parse(json));
});

API

| Export | Description | | --- | --- | | init() | Load the WASM module. Call once before parse. | | parse(data: Uint8Array) | Parse a media file buffer. Returns a JSON string, or null if the format is not recognized. | | version() | Return the package version string. |

Output shape

parse returns JSON matching revelo's MediaInfo-style export: an array of stream objects, each with a kind (General, Video, Audio, Text, Image, EXIF) and a fields array of { name, value } pairs.

[
  {
    "kind": "General",
    "fields": [
      { "name": "Format", "value": "MPEG-4" },
      { "name": "Duration", "value": "1 min 30 s" }
    ]
  },
  {
    "kind": "Video",
    "fields": [
      { "name": "Format", "value": "AVC" },
      { "name": "Width", "value": "1920 pixels" }
    ]
  }
]

Bundlers

The package is ESM ("type": "module"). With Vite, webpack, or Rollup, import as shown above. The WASM binary ships inside the package; init() resolves it automatically.

If your bundler strips side-effect imports, keep the default import:

import init from "revelo-wasm";
await init();

Building from source

Requires wasm-pack and the wasm32-unknown-unknown target:

rustup target add wasm32-unknown-unknown
wasm-pack build crates/revelo-wasm --release

The build output lands in crates/revelo-wasm/pkg/.

Related

• revelo — the Rust metadata engine
• revelo on crates.io — native Rust API

License

BSD-2-Clause. See LICENSE.