Try YouTube-Dl. It downloads YouTube videos from the command line and works on Linux, Unix, and Mac OS.
Lets see how we can install and use it in Ubuntu, first of all open the terminal and run the following command to install it.
sudo apt-get install youtube-dl
Once the installation is completed, you are ready to download YouTube videos. Now use the following general syntax of the command to download YouTube vide.
youtube-dl –o filename.flv URL
where filename.flv should be the name with which you wish to save the downloaded video and URL is the address of the YouTube video. For e.g, see code below,
youtube-dl –o filename.flv http://www.youtube.com/watch?v=Ut3HAdCGHxs
The following screenshot illustrates the download process of the video in Ubuntu terminal: