switcher vs vision mixer

switcher

noun
  • Synonym of vision mixer (“device for selecting between video sources”) 

  • A switchmode power supply. 

  • A railway locomotive used for shunting; a shunter. 

  • One who or that which operates a switch. 

  • One who or that which switches, or changes to something else. 

vision mixer

noun
  • A device used to select between different video sources and sometimes to create composite effects. 

  • The person who operates such a device. 

How often have the words switcher and vision mixer occurred in a corpus of books? (source: Google Ngram Viewer )