VideoSnipper is a Simple, Free Video Downloader basing on WebExtensions API. It caches the video source in the html page, and you can do follows through the Addon:

Copy the video source to the system Clipboard, so you can do whatever you like, such as sharing the video source or downloading in other devices
Download the video source with FireFox default Downloader

How to use:

Step 1. Visit the page you enjoy the video
Step 2. Play the video (Mostly unnessesary, just do this if failed in Step 3)
Step 3. Click/Tap the button of this Addon in tool bar( Top-right the FireFox Window on PC, in menu displayed after tap the Top-right Button on Phone)
Step 4. You will receive a notice if source exists, and the link copied and download task auto set

* You can change the default action in the Config page if you don't need to Copy/Download/Alert. * You can get the code at https://github.com/nICEnnnnnnnLee/VideoSnipper Update log:

Version 2.3

Provide the function to open the embed pages if failed at current page, you can do things again in the new pages and then most likely susucceed.
If you find puzzled with the new feature, just disable it in the config page, and things will act as it did in Version 2.2.

Version 2.2

Add Config to decide whether to alert, copy and download onClick the Addon button

Version 2.1

Minimize the requied Permission "tabs" to "activeTab"
Cut the Permission "notifications", using default js function "alert" instead
Trans the url from to Relative URL to ABS URL