YouTube Download and Convert — devprojection

YouTube downloader and audio conversion for your Firefox browser. Video conversions supports all resolutions including full HD
For websites other than YouTube, we allow you to only download the video (the formats depend on the original URL)
Audio conversion are done only for YouTube, these output formats are supported:

-MP3
-OGG
-FLAC
-AAC.

Note:The extension also allows you to download DASH video and audio streams, but you will need the video and audio mixing software available, called 'youtube joiner', for Windows on the website.
In this way, you need to download the DASH video file and the DASH audio file separately, then combine them with the tool to get a normal video.