Two years after its last release, I finally found the time - and a reason - to rewrite the playVideoOnDreambox browser extension, making it compatible with newer Firefox versions.
The extension adds a button to Firefox that sends the currently playing video to the Dreambox satellite receiver - useful for showing a Youtube video to the family on the large TV screen.
Dreambox' media player does not support playing websites, so the extension needs to extract the URL of the video embedded on the current page. I did not implement this myself, but rely on youtube-dl for this.
Mozilla dropped support for "classic" extensions in Firefox 57; you have to use the "web extension" format now that severely restricts the things you can do. The main problem for me is that extensions cannot execute other programs on the computer anymore (unless the are registered manually with the browser and speak a certain protocol). This broke the my old extension that called youtube-dl directly.
I could have written a youtube-dl proxy script that users would need to register in their browser and that speaks said protocol. But instead I made the Firefox extension rely on the playVideoOnDreambox proxy application, just as the Android app does.
So when your browser shows some video and you click "Play on Dreambox", the extension sends the page URL to the proxy server web app running on some machine in your network. This proxy calls youtube-dl to find the video URL, and then instructs the Dreambox to play the video.
Download
You can download the playVideoOnDreambox firefox extension version 0.6.0 from its homepage or the Mozilla Add-Ons page.
You migh be interested in the playVideoOnDreambox Android app that lets you "share" the video with your satellite receiver.