@rair/hls-server

hls-server

Simple HTTP middleware for serving HTTP Live Streaming (HLS) compatible media streams.

Forked from t-mullen to support streaming AES decryption in a non-standard way.

Usage

First you need a compatible media stream (see @rair/ingest).

In this fork media must be explicitly configured in the mediaConfig option. This maps between route paths (excluding the basename) and configuration objects. Commonly this would contain a dir field to tell the fs provider where to find the files for that piece of media. This decouples the file system structure from the server and allows non-fs providers to receive free form config.

Detailed way:

var HLSServer = require('hls-server')
var express = require('express')

const app = express()

var hls = HLSServer({
  mediaConfig: {
    'sample_vid': {
      dir: '/home/user/media/sampleVid/',
      keyPath: '/home/user/media/sampleVid/aes.key' // may also have other fields that are available to the provider and transformation callbacks
    }
  }
})

app.use('/stream', hls.middleware)
app.listen(8000)

Adding a stream decrypter

The HLSServer constructor accepts an optional parameter opts.segmentTransformation. If provided this must be a function that accepts the req object and returns a stream which can be used to transform a single segment. Only media segments (e.g. .ts) files will be piped to the transformation. Manifests will be passed through as is. This can be used to do streaming decryption server side.

The req object can be used to set a unique key and IV per segment/media stream.

Example using AES decryption where all streams share a key and IV (don't actually do this):

const crypto = require('crypto')
const key = ///
const iv = ///
const segmentTransformation = req => {
  return crypto.createDecipheriv('aes-128-cbc', key, iv)
}
var hls = HLSServer({
  path: '/streams',     // Base URI to output HLS streams
  dir: 'public/videos'  // Directory that input files are stored
  segmentTransformation
})

app.use('/stream', hls.middleware)
app.listen(8000)

Using In-Memory Streams

By default, this module assumes files are kept in a directory on the local filesystem. If you want to stream files from another source (or don't want to relate URL paths to filesystem paths), you can specify a provider in the options like so:

var hls = HLSServer({
  provider: {
    exists: function (req, callback) { // check if a file exists (always called before the below methods)
      callback(null, true)                 // File exists and is ready to start streaming
      callback(new Error("Server Error!")) // 500 error
      callback(null, false)                // 404 error
    },
    getManifestStream: function (req, callback) { // return the correct .m3u8 file
      // "req" is the http request
      // "callback" must be called with error-first arguments
      callback(null, myNodeStream)
      // or
      callback(new Error("Server error!"), null)
    },
    getSegmentStream: function (req, callback) { // return the correct .ts file
      callback(null, myNodeStream)
    }
  }
})

See src/fsProvider.js for the default provider using the local filesystem.