I have never tried it myself but with certain CDMA phones u can convert any audio into a ringer.
first you will have to download a video encrypting device such as EO Video and convert the movie u got into .wav format or .mp3 format. After that u can get a MIDI converter and it will convert the .wav/.mp3 into MIDI format which can be used for samsungs. For all these programs just go to -- or go to the EO video website.
to get it onto the fone u can email it as an attachment and download/save it. Heres the tricky part: u gotta find where it was saved to, usually it saves to ur audio section but i really dont noe exact location (never used any Samsung A650 before) but once u find it u can apply as a ringtone.
it should work but i havent tried it out myself so good luck!