dreaminglive, I recommend oCam as its easy like a baby toy. You get this green rectangle which can be moved and sized as wanted to indicate the recording area. One click at the codecs button to choose the mp4 with h264 codec. One click at the audio button to choose the audio input. One click at the menu button to configure the recording parameters. I make all of my gifs with oCam. Just put the green frame where you want it and hit the F2 key. But don't forget: If you record an area with uncommon ratio you will get in trouble if you try to put it in a second encoding as most encoders offer standard presets with standard video resolutions. So keep that in mind. But this step should be obsolete if you can record with h264 at the first time. :) I also tried out OBS studio but it offers not that flexible frame and doesn't get out of the view. Kind of weird handling and more focus on streaming and post production. Anyway. oCam is more than enough. Try it out. Maybe it fits your needs. :)