mediainfo.js

This is a JavaScript port of the excellent MediaInfoLib and can run directly in a browser or in Node.js. It is transpiled from C++ source code using Emscripten.

Demo

Try mediainfo.js in your browser: https://mediainfo.js.org

Usage

Browser

You can either use a CDN to include the script file directly in your page or use a JavaScript bundler like webpack.

CDN:
<script type="text/javascript" src="https://unpkg.com/mediainfo.js/dist/mediainfo.min.js"></script>
Bundler: npm install mediainfo.js

Be aware that mediainfo.js is a WebAssembly port of MediaInfoLib. Thus it depends on MediaInfoModule.wasm which weighs around 2.4 MiB. The WASM module is loaded automatically and needs to be made available from the same location mediainfo.js is served from. This is the case for the CDN version. If you're using a bundler, you need to take care of this yourself. There are examples for React/webpack and Angular on how to achieve this.

Node.js

Install mediainfo.js from NPM.

$ npm install -g mediainfo.js

You can use it directly from the shell.

$ mediainfo.js /path/to/media.avi

Or use it as a library.

require('mediainfo.js')().then((mediainfo) => {
  // mediainfo ready…
})

Examples

API

`MediaInfo(opts, successCallback, errorCallback)`

Create an instance of mediainfo.

Defaults: opts = { chunkSize: 256*1024, coverData: false, format: 'object' }

chunkSize: Chunk size used by analyzeData (in bytes)
coverData: Whether to extract binary cover data (Base64-encoded)
format: Format of result value (choices: object, JSON, XML, HTML or text)
locateFile: Optional callback function to override MediaInfo.wasm location. Must return URL/path to file. Helpful if you want to serve MediaInfoModule.wasm from a custom location.
(url, scriptDirectory) => pathToFile
Returns a Promise if no callback is given.

const MediaInfo = require('mediainfo.js')
MediaInfo(opts, callback, errorCallback)

Media files can be several gigabytes in size. The preferred way is to load data in chunks to prevent memory exhaustion. analyzeData is a helper method that facilitates this somewhat cumbersome process.

`mediainfo.analyzeData(getSize, readChunk, cb)`

Convenient method for analyzing a buffer chunk by chunk.

You need to provide two callback functions. They can either return a Promise or directly the value.
- getSize() - Return total buffer size.
- readChunk(size, offset) - Read data chunk of size with offset and return an Uint8Array.
Returns a Promise if no callback is given.

Low-level methods

The mediainfo object also exposes a number of low-level methods analogous to the MediaInfoLib buffer methods.

close(), inform(), openBufferContinue(data, size), openBufferContinueGotoGet(), openBufferFinalize(), openBufferInit(size, offset)

Build

Install Emscripten preferably using Emscripten SDK.

$ git clone https://github.com/emscripten-core/emsdk.git
$ cd emsdk
$ ./emsdk install 1.39.15
$ ./emsdk activate 1.39.15
$ source ./emsdk_env.sh
$ export PATH=$PATH:$(pwd)/upstream/bin # for wasm-opt

Note: Versions 1.39.16 and later of Emscripten give compile errors.

In the project root of mediainfo.js run the following to build.

$ npm install
$ npm run build

Find the resulting files mediainfo.js, mediainfo.min.js and mediainfo.wasm in the dist directory.

Tests

You can run a test suite against the dist build.

$ npm run test

License

This program is freeware under BSD-2-Clause license conditions: MediaInfo(Lib) License

rzurad/mediainfo.js