In addition, when making, you need to adjust the page of your PPT according to the size displayed at that time, otherwise it will be black and ugly.
Usually it is 16:9 if it is an LED. If it's a projection, 4:3 is fine.
In the production process, don't zoom in and out to change the size. Be sure to zoom in and out in the same proportion, otherwise you will become thinner or fatter and the photos will be ugly.
It is suggested to use audio and video and buy templates online, which is effective and simple.