If you'r like me and use ZoneMinder, or I would venture any IP Camera monitoring Suite, then it has its own overlay, and I think for court purposes this is best, because it "should" line up with all the other cameras. I didn't like having the 2nd overlay and to make it worse, the time was off/different then my ZoneMinder Overlay.
To make you'r life easier if your UI is in chinese, read here
Then just go to Set UP >> Video >> Video OverLay >> Whatever Setting >> Shut Off >> Determined.
Personally I shut them all Off.