Open a file, then go to Media > Convert! Save. In the file tab, click on the Convert/Save button. Select the 'File' checkbox under 'Outputs'. Enter a file name. Make sure There are many transcoding options available that draw raw input is unchecked. Then select an encapsulation, that is basically the format under 'profile'.
Select a video codec and audio codec under the 'Video codec' and 'Audio codec' tabs. You can save files in a format to be played on a portable media device.
Click on Save.