How to cut a 3gp file to part files without a format change?

[kop]

Hello!
Nokia 6280 mobile phone and some others cannot fast forward a video file or goto a position. An incoming sms or call stops, not pauses, a video playback, thus rewinds it to the beginning. Therefore, I need to cut 3gp files to part files to be able to jump to a next part file instead of the fast forward. How to cut a 3gp video file in silent or dark scenes to part files without complete reencode, with only border group of pictures reencode, or without a format change?
Best regards,
Dmitry

[Baldrick]

Please don't cross post. Continue in https://forum.videohelp.com/topic358252.html