cutting with ffmpeg results in few seconds of black screen, how do i fix this?
Most videos use codecs which perform temporal compression, so a specified cutpoint may rely on frames before (and after) that cutpoint to be correctly decoded. So, when you use ffmpeg to trim videos and use copy mode, ffmpeg has to include all frames before and after the trimmed segment which are needed to decode the segment correctly.

So, you have two options, use copy mode but set a switch which will allow all players to correctly play these files

ffmpeg -ss %2 -t %3 -i %1 -vcodec copy -acodec copy -avoid_negative_ts make_zero %~n1_cut%~x1


(this will likely result in output that starts before your cutpoint)

or re-encode the streams

ffmpeg -ss %2 -t %3 -i %1 %~n1_cut%~x1