Simple YouTube Chapter Extractor

Copy the text containing chapter information directly from YouTube and convert it into simple mkvmerge chapter format to embed in your downloaded YouTube video.

Requirements

Deno installed (tested on 1.5.3)
mkvmerge command line tool or MKVToolNix GUI installed

Installation

Install or update:

deno install -Af https://deno.land/x/simple_youtube_chapter_extractor@v1.0.0/youtube-chapter-extractor.ts

Uninstall

https://github.com/denoland/deno/issues/3139

rm $(which youtube-chapter-extractor)

Usage

Find a video that uses the recent YouTube chapters feature:

example

You can download YouTube videos using youtube-dl or one of many browser extensions
Under the video in the description there should be text including chapters. Copy and paste all the text into a file for use with this program. It might look like:

⭐️ Course Contents ⭐️
Introduction
---------------------
⌨️ (00:00:00) Introduction
⌨️ (00:02:02) Course overview
⌨️ (00:04:38) Course Project
⌨️ (00:05:51) What is Deno
⌨️ (00:08:19) Course project (Survey app) demo
⌨️ (00:11:54) Install and Getting started
⌨️ (00:14:34) Write "Hello World"
⌨️ (00:15:50) Main Features

Text file source formats allowed

YouTubers can create the list of chapters in any way they like, the following are some common ones supported:

The time stamp in either 00:00 or 00:00:00 format followed by either:

space title:

03:00:00 Introduction

) space title:

⌨️ (00:00:00) Introduction

space - space title

02:00 - Introduction

The current regex used is:

/(?<time>\d{2}:\d{2}:\d{2}|\d{2}:\d{2})\)?\s(\-)?(\s)?(?<chapterTitle>.*)/g;.

To see what it does paste it into regex101.com. Please contribute more formats to help others use this program!

Extract chapters from text file

youtube-chapter-extractor [name of text file to process]

or if you did not install it and running from source file:

./youtube-chapter-extractor.ts [name of text file to process]

Merge chapters into video file

Use MKVToolNix GUI which contains all the functionality of mkvmerge

chapter-file

Download mkvmerge from the home site and use:

mkvmerge \
  --chapters originalfilename_chapters.txt \
  -o output-file.mkv \
  input-file.mkv

Flathub and use:

flatpak run --command=mkvmerge org.bunkus.mkvtoolnix-gui --chapters originalfilename_chapters.txt -o output-file.mkv input-file.mkv

Development

deno test to run tests.

deno --unstable lint youtube-chapter-extractor.ts to lint.

Suggested contributions

Add more text chapter formats
Add more tests
Automate mkvmerge usage
Automate youtube-dl chapter extraction from JSON file. The feature is currently broken in 2020.11.17, youtube-dl --write-info-json results in "chapters": null

Suggested things not to bother with

Automating everything using the YouTube API. It has been done by https://github.com/gabrielfroes/youtube-chapter-extractor, and it seems to keep breaking and be too complex.

The future of video sharing is federated peer to peer, we must be free to express ourselves without corporate or government censorship. Have a look at https://joinpeertube.org/.