Fragmentation of mp4

[Th0ru5]

Hello,
I'm trying to make a software witch will record RSTP stream from ip camera to mp4
But i can not find way to make vlc to fragmentate this mp4 into 15min fragments without loosing any second of the video and audio.
If i'm killing the vlc process and start new one i'm loosing something around 2s of video and audio.
Someone know how i can achive this?

Thank you for help.