mediaplex

Mediaplex

Mediaplex is a tiny media transcoding utility for Node.js that allows you to probe media files for metadata and use an Opus encoder/decoder.

🏗️ Please note that this package is a work in progress.

Installation

To install Mediaplex, run the following command:

$ npm install --save mediaplex

Current Features

Mediaplex currently supports the following features:

• Probe media files for metadata
• Opus encoder/decoder

More features are coming soon.

Examples

Probe metadata

You can use Mediaplex to probe media files for metadata. Here's an example:

const mediaplex = require('mediaplex');

const stream = createReadStream('./media.mp3');
const { result } = await mediaplex.probeStream(stream);

console.log(result);

/* Sample Output */
{
    channels: 2,
    sampleRate: 44100,
    framesPerBlock: 0,
    codec: 4099, // use `CodecType` enum to validate this
    nFrames: 796032,
    duration: 18, // seconds
    metadata: [
        { name: 'TXXX:major_brand', value: 'mp42' },
        { name: 'TXXX:minor_version', value: '0' },
        { name: 'TXXX:compatible_brands', value: 'isommp42' },
        { name: 'TSSE', value: 'Lavf59.6.100' },
        { name: 'TIT2', value: "..." },
        { name: 'TPE1', value: '...' },
        { name: 'TALB', value: '...' },
        { name: 'TCON', value: '...' },
        { name: 'TPUB', value: '...' }
    ]
}

This will output an object containing information about the media file, including the number of channels, sample rate, codec, duration, and metadata. The default probe size is 10MB, but you can adjust this as needed by passing the second argument to probeStream:

// probe only 1024 bytes
const { result } = await mediaplex.probeStream(stream, 1024);

// probe 5 MB
const { result } = await mediaplex.probeStream(stream, 5 * 1024 * 1024);

// add a note

⚠️ Probing a stream is non-blocking as it is done in a worker thread. But probing a buffer is a blocking operation.

Opus Encoder

Mediaplex also includes an Opus encoder/decoder. Here's an example:

const { OpusEncoder, getOpusVersion } = require('mediaplex');

console.log(getOpusVersion()); // libopus xxx

const encoder = new OpusEncoder(48000, 2);

const encoded = encoder.encode(buffer);
const decoded = encoder.decode(encoded);

You can use OpusEncoder to encode pcm data to opus and decode opus data to pcm format. Stream interface is provided by @discord-player/opus package.

Opus Benchmarks

Mediaplex includes benchmarks for the opus encoder/decoder. Here are the results of the benchmarks on a Windows 11 machine with an i7-8700 3.2GHz processor:

$ yarn benchmark

Running "OpusEncoder Benchmark" suite...

  mediaplex:
    3 538 ops/s, ±0.63%   | 15.96% slower

  @discordjs/opus:
    3 168 ops/s, ±0.53%   | 24.75% slower

  @evan/opus:
    3 283 ops/s, ±0.25%   | 22.02% slower

  @evan/opus (wasm):
    2 242 ops/s, ±0.39%   | 46.75% slower

  opusscript:
    4 210 ops/s, ±0.20%   | fastest

  opusscript (no wasm):
    245 ops/s, ±3.69%     | slowest, 94.18% slower

Finished 6 cases!
  Fastest: opusscript
  Slowest: opusscript (no wasm)

Running "OpusDecoder Benchmark" suite...

  mediaplex:
    10 726 ops/s, ±0.50%   | 9.42% slower

  @discordjs/opus:
    11 841 ops/s, ±0.55%   | fastest

  @evan/opus:
    11 382 ops/s, ±0.46%   | 3.88% slower

  @evan/opus (wasm):
    7 461 ops/s, ±0.32%    | 36.99% slower

  opusscript:
    6 138 ops/s, ±0.38%    | 48.16% slower

  opusscript (no wasm):
    2 252 ops/s, ±0.73%    | slowest, 80.98% slower

Finished 6 cases!
  Fastest: @discordjs/opus
  Slowest: opusscript (no wasm)

These benchmarks compare the performance of Mediaplex's Opus encoder/decoder to other popular Opus libraries.