The videos that you downloaded from Youtube and other streaming sources would be in FLV format. For making these videos compatible with your mobile video players like Smartmovie And Divx you have to convert it into Avi format. Pazera Flv To Avi Converter is a free tool for converting Flv Videos into Avi format.
You can download this free software from here
This Flv To Avi Converter is very simple, And its very good too.