Mp4 or 3gpp Files merge/joining and decoding parser

[fidogenial]

Hi

I am new to this mp4 parsing. I have mp4 and 3gp fragmented files.. trying to write an application in c or c++ to merger/joining these files and also mp4 and 3gp parse decoding so that i can get video and audio encoded files... Any help on this would be greatly appreciated..

thanks