litestream-backend

Simple MPEG-DASH streaming library with JWT security feature.

litestream-backend is a NestJS application.

Main objectives:

• to provide easy way of securely sharing MPEG-DASH streams
• be simple and lightweight

How it works?

1. You have your application that needs to provide MPEG-DASH video streaming for its clients. (lets call it Main Server, accessible with URL: myapp.pl)
2. You install litestream-backend so its accesible for example through subdomain: stream.myapp.pl (lets call it Streaming Server)
3. Main Server sends POST HTTP request with password to Streaming Server
4. If password authentication is successfull Main Server gets JSON response containing everything that MPEG-DASH video player needs to correctly play video stream (JWT token protected stream URLs, subtitles, chapters, titles).

What litestream-backend can do?

• Share URLs containing JWT token that point to MPEG-DASH manifest file
• Server-to-Server plaintext password authorization
• Can handle subtitles (if provided in stream directory)
• Stream can contain many chapters (many MPEG-DASH streams under the same stream id)

What litestream-backend can't do?

• Convert videos to MPEG-DASH format. You need to do it yourself. (or use litestream-tool's generate dash command)
• Create Media directory structure

Installation & Running dev

Clone the repository. Run npm install command in litestream-backend directory. Run npm run start:dev to start application in dev mode.

cd litestream-backend
npm install
npm run start:dev

Default .env configuration for dev is:

MEDIA_DIR=D:\Media\
PASSWORD=123456
SECRET=3FOHznZKQlSXXosRO0W6lXwpJL1taGx3
URL=http://localhost:8080

You must change MEDIA_DIR to your own path. Rest of the configuration can stay the same in dev.

Running in production

litestream-backend is a NestJS application and can be build for production with npm run build command.

Configuration for production

Before you run litestream-backend its recomennded to change .env file variables:

• set your own MEDIA_DIR which is a directory containing all the media directories
• set your own PASSWORD that is used to access video streams
• set your own SECRET that is used to sign JWT tokens (must be 32 bytes)
• set URL to your own address under which litestream-backend is accessible

Media directory structure

Stream files handled by litestream-backend must follow certain format in media directory.

Example:

<MEDIA_DIR>/
    css-for-beginners/
        chapters.json
        chapter_1/
            <MPEG-DASH files>
        some_other_chapter/
            <MPEG-DASH files>
        chapter_with_subtitles/
            <MPEG-DASH files>
            subs/
                en.vtt
                de.vtt
                subs.json

1. Media directory is a directory that is placed directly under MEDIA_DIR directory.
2. The name of the Media directory is called a stream_id
3. Media directory (in the example css-for-beginners) contians file chapters.json that describes every chapter of a stream in JSON format.
4. Every directory placed directly under Media directory and described in chapters.json is called Chapter directory (in the example: chapter_1, some_other_chapter and chapter_with_subtitles).
5. Every Chapter directory contains MPEG-DASH files (audio/video segments, manifest). Optionally Chapter directory can contain subs directory containing subtitles (in example chapter_with_subtitles).
6. subs directory contains subs.json that describes subtitles.

Example chapters.json file contents:

[
  {
    "title": "Title for chapter 1",
    "duration": {
      "h": 1,
      "m": 13,
      "s": 33
    },
    "dir": "chapter_1"
  },
  {
    "title": "Title for chapter 2",
    "duration": {
      "h": 1,
      "m": 15,
      "s": 46
    },
    "dir": "chapter_2"
  }
]

Example subs.json file contents:

[
  {
    "src": "en.vtt",
    "kind": "subtitles",
    "language": "en",
    "label": "English",
    "contentType": "text/vtt"
  },
  {
    "src": "no.vtt",
    "kind": "subtitles",
    "language": "no",
    "label": "Norwegian",
    "contentType": "text/vtt"
  }
]