About nrkcache

The sizeable Video-on-Demand offerings of the Norwegian Broadcasting Corporation can be difficult to watch over a slow or unstable network connection. Programs recorded at 1080p quality often have average data rates in excess of 4500 kbit/s (550 KiB/s), which even today is sometimes unavailable in rural areas underserved by commercial telcos. Additionally, some network connections, particularly those that rely on certain wireless technology or ancient copper wiring, are so unstable that local caching is the only way to watch a video from the internet uninterrupted at any quality setting.

This script aims to prevent modern incarnations of “film tear” by creating just such a local cache of HTTP Live Streaming segments, then combining them into a single MPEG-4 container supported by many modern video players. It is specially designed for the NRK Video-on-Demand offering and will not work with other HLS sources without modification.

System Requirements

• Perl 5.37.9+
• FFmpeg
• YT-dlp (some alternatives are supported as well)

Installation

Released versions of nrkcache may be installed via CPAN:

cpanm Video::NRK::Cache

To install a development version from this repository, run the following steps:

git clone https://github.com/johannessen/nrkcache
cd nrkcache
cpanm Dist::Zilla::PluginBundle::Author::AJNN
dzil install

You can also try to run nrkcache.pl directly from the repository directory without installing the software, but this method is only provided for backwards compatibility and may not work very reliably.

Contributing

All contributions are welcome. Simply create a new issue or a pull request.

This is a “Pure Perl” distribution, which means you don’t need Dist::Zilla to contribute patches. You can simply clone the repository and run the test suite using prove instead.

Legal Considerations

Use of this script would appear to be legal in Germany, falling under both of the caching exceptions laid down in § 44a UrhG. The Norwegian Åndsverkloven § 4 seems to contain the same exceptions – not surprising, since both laws are implementations of the InfoSoc Directive (2001/29/EC). Use would apparently also be legal in the U.S. under the “fair use” doctrine.

That said, any use of this script is your responsibility. In particular, you probably shouldn’t share your locally cached copies of NRK content with other people. Doing so would likely constitute a copyright infringement on your part.

This script is in the Public Domain.

Alternatives

The following alternatives to nrkcache (this script) are known.

• nrk-download is another solution specific to NRK that supports downloading entire series of TV shows in one go. It automatically embeds subtitles into the video file, but does not seem to offer meta data retrieval.

• yt-dlp is being maintained very well and is the backend used by nrkcache since version 3. It offers a great deal of configurability, which may make its use more complicated in certain cases.

• svtplay-dl purports supporting NRK as well.

• nrkcache version 1 is no longer working properly after changes to NRK's HTML pages. However, its component scripts may be useful individually in some rare cases.