Currently a few options are requested, split after time / size, split or pause the current recording and keep on recording later. In general a few more things have to be taken into consideration for these options to work without any flaw or breaking the files.
The file format and codec are probably the most important points. For example if you just cut an mp4 file using x264 as usual "in the middle of writing", it would probably break both the first and second part of the video. Instead the first part needs to be finished and "finalized" while the second part has to be started like a new recording, new keyframe etc. All this within a few ms to record everything without missing a frame.
For other file formats and codecs this process can be easier or even more complicated.
