Frames of 17 minutes long video clip compressed to about 20/30 seconds, but audio left untouched for the rest of non functional video clip...

Have no idea on how to fix this one...anyone welcome to advise me about solution. Thank you

Factory settings say 15 frames per second...this is otherwise best free screen recorder out there(all others have watermarks on them or are limited to 10 minutes per recording and then encoding that costs extra time). Any gestures welcome...