Raspberry PI4

I have a raspberry PI4 with usb mic in installed on board. I need to record with gstreaner the video that come from ip camera by rtsp and the audio from microphone in a mp4 container. I already did it but audio and video are not syncronized and i'm not able to do it. I need to syncronize audio and video and save it in mp4 and also restream syncornized rtsp. Save files should be splitted by minutes that should be setted by parameter. Example split each 5 minutes files.