I try and download videos from youtube and convert them but it says failed convert :( i open FFpmeg on terminal and it says "* THIS PROGRAM IS DEPRECATED * This program is only provided for compatibility and will be removed in a future release. Please use avconv instead." I try and use avconv but still fails, I have VLC installed also someone said it might help... But it didn't =[
You can try a web-based tool for downloading youtube videos to your computer. Most sites will give you many options for which type and size the video will be. One site that has worked well for me is www.keepvid.com.