convert-chapters

Converts chapters extracted from YouTube videos using youtube-dl to a format suitable for MKVToolNix.

Background

Some time ago YouTube added a feature that lets creators break up their videos into chapters.
youtube-dl tool has the option to add chapters to the video being downloaded using --write-metadata, but AFAIK there is no way to fetch chapters separately in a format supported by MKVToolNix/mkvmerge (i.e. OGG or Matroska XML).

This project was created mainly to explore development options with Micronaut and GraalVM. More precisely I wanted to see how good does the native image feature work with Jackson and Picocli. (SPOILER: works fine, albeit not without quirks).

Building

Building requires at least Java 11.

The application can be built as a fat JAR using shadowJar Gradle task: ./gradlew shadowJar. The JAR can be found in build/libs/convert-chapters-0.1-all.jar.

For native image build a GraalVM SDK is required (tested using GraalVM Java 11 20.3.0). Build is executed with nativeImage Gradle task: ./gradlew nativeImage. The executable native image is found in build/native-image.

Using

Usage: convert-chapters [-fhV] [-i=<inputLocation>] [-l=<chapterLanguage>]
                        [-o=<outputLocation>] [-t=<type>]
Converts YouTube chapters to OGG or Matroska format.
  -f, --force                Overwrite output file if exists.
  -h, --help                 Show this help message and exit.
  -i, --in=<inputLocation>   Input file. Defaults to standard in.
  -l, --chapter-language=<chapterLanguage>
                             Matroska chapter language. Should be a valid BCP
                               47 code.
                               Default: und
  -o, --out=<outputLocation> Output file. Defaults to standard out.
  -t, --type=<type>          Output format. OGG for OGG format, XML for
                               Matroska XML.
                               Default: XML
  -V, --version              Print version information and exit.

The application uses the JSON metadata of a video that can be obtained using youtube-dl --print-json -s <URL>.
If redirected to the application, an XML is written to standard out: youtube-dl --print-json -s <URL> | convert-chapters

License and Legal Disclaimer

This software is licensed under MIT License. Full text can be found in LICENSE. By using the software you agree with the license terms.
This project is in no way affiliated with youtube-dl or any other software products.
All trademarks and product names mentioned here belong to their respective owners.