For the moment i can screenshot each frame. But i want to output video with sound
OBS Studio is very good - you can even record a mic and game sounds on separate channels.
i was angry with those softs and preferred to use Blender to capture. But , wow, this is good ! My game remains at 60fps whole time. Thanks a lot !!
Also if you have a decent videocard you can just record it with its driver/software. this would be the lightest/best option.