help me with 3gp problem please

i have just been sent a 3gp file from a mate who has a p900 but when i try to play it i get the message . unable to play sound or video clipptry playing partialy. i can play it but there is no sound wich i could do with. the clip details are format/video/mp4-es
any one help please do i need codecs or something ?
thanks

sorry forgot to add i got the file sent to my 6600

Maybe the P900 recording format is different to the 6600.

Have you tried sending the 3GP video to your computer and using Nokia Multimedia Convertor to convert it to 3GP again (probably to Nokia's "format")?

Or ask your friend to send you a different 3GP video ...