The Leawo MP4 converter is a more powerful video to Mp4 converter than the Free MP4 converter, because this advanced version has some advanced functions that enable your conversion to be easier and handier. The first is that it can trim video to retain a short duration. This function allows you to cut video length to retain a short duration. And the second is to crop video to extract the video black margins. Under "Trim", set the "Start Time" and "End Time" points for a video length so as to adjust video dimension to remove black margins. The third function is to set audio and video effects: video brightness & contrast, audio volume. Under “Effect”, you can set audio and video effects by dragging the slides for Brightness, Contrast, and Volume to improve better quality.