Aslam o alikum friends.
Everyone want download video file from youtube but somebody want covert able file download i have solution for online converter and download file.if you want video file in 3gp,mp4,avi and mp3 file from you tube you can visit this site http://convert2mp3.net/en/
1- copy youtube video URL
2- open website http://convert2mp3.net/en/
3- past URL and Select option to convert for any extension