Multi channel switcher?

[bobaandy]

Hey guys, just wondering something...

I've worked extensively with video switchers, although they are all usually old/cheaper ones. I've heard them referred to as "having only one channel."
What does this mean? What is a channel, and what is the advantage to having more then one? How many is good?

[Cail Young]

My guess would be it's referring to having one M/E channel (mix/effect) - basically you can only show two inputs at once (sounds like a lot, until you want to put a graphic overlay on top of a picture-in-picture with a graphic background) - more M/E pipelines means more advanced compositing for your show.

Most basic TV shows will need at least two M/Es, some like sports need many more.