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...
Progress: 100%

  mediaplex:
    3 502 ops/s, ±0.84%   | 16.04% slower

  @discordjs/opus:
    3 185 ops/s, ±0.17%   | 23.64% slower

  opusscript:
    4 171 ops/s, ±0.34%   | fastest

  opusscript (no wasm):
    261 ops/s, ±0.85%     | slowest, 93.74% slower

Finished 4 cases!
  Fastest: opusscript
  Slowest: opusscript (no wasm)

Running "OpusDecoder Benchmark" suite...
Progress: 100%

  mediaplex:
    9 838 ops/s, ±0.38%    | 16.96% slower

  @discordjs/opus:
    11 848 ops/s, ±0.40%   | fastest

  opusscript:
    6 100 ops/s, ±0.23%    | 48.51% slower

  opusscript (no wasm):
    2 589 ops/s, ±0.20%    | slowest, 78.15% slower

Finished 4 cases!
  Fastest: @discordjs/opus
  Slowest: opusscript (no wasm)

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