Videos 3gp Incesto How Come My Phone Doesnt Play 3gp Videos?

How come my phone doesnt play 3gp videos? - videos 3gp incesto

My phone is LG CU920. I have a Micro SD memory card to 2GB. I have the 3GP video files on the memory card and from there the game, he does not see play video, but u can hear the audio. What must I do to play on the phone?