Hi where i can find and change supprted file types(.jpeg,.gif eg.), i want to add .mpg .mov also to make it supported it will just give a link to the file so when clicked to medium size preview will download movie
You will want to find and edit the generate_thumbnail() function in plog-functions.php. However, keep in mind passing the file to phpThumb will either (1) provoke an error from phpThumb or (2) cause a fatal error in PHP itself.
You will have to interrogate the MIME filetype and determine what to do with files that aren't compatible with GD/phpThumb and do something else with them. I would suggest making a base image, adding an icon (like a musical note for wav and mp3, a movie reel for mpg, mov and avi) and rendering the running time below it.
You would have to somehow edit the large thumb page to actually embed the media or display a large-thumb of the above.
Also, keep in mind you will either likely have to change your upload_max_filesize to compensate for larger files.