I downloaded a video song from youtube, it plays on the laptop but doesn’t plays on my player to watch on tv.
I guess will have to change the video extension. What extension to change? Any free portable recommended converter?
try with zamana
By player if you mean a standard DVD player then you will have to convert the file(s) to the .vob format.
If your using an Xbox or PlayStation convert to .avi format and Xvid codec.
I have Sony DVD Player. I converted the song to .vob with DamnVid Portable but the player gives video data error.
UPDATED - Sony CD/DVD Player DVP SR320. It also plays from USB so I am trying to play from USB.
Have your ever played anything else off the USB before ? Just encoding a file to VOB is not going to work. VOB files must be accompanied with IFO and BUP files and be in standard format.
This will create the necessary files - http://www.videohelp.com/tools/Simple-DVD-Creator
Sony DVD players support MPEG4 playback so if you encode it to xvid or divx you should be able to play it directly from the USB with no problems.
At Sourceforge there are various Video converter programs to be found.
Format factory is free and very good, you could try 
Never let me down, work wonderful you can convert in any format you what, even make mp3 from video file, anything you want.