I saw the movie on TV, it was animated, I saw it probably in the early 90’s. It was kind of Reading Rainbow style, but I seem to recall the person narrating was an English woman, I could be wrong about that.
There was this society of people and one day their scientists discovered that they were all a part of someone else’s dream. The people all began panicking that one day the man would wake up and they would all cease to exist. So they invented a machine that would allow them to travel out of the dream and into the real world and back again. I remember this scene with a couple of very big guys all wearing pillows on their feet surrounding a sleeping man then picking the whole bed up and bringing him back into the dream where they placed him in a completely soundproof room. Hooray, they are all saved! But then the man’s dream changed. He started dreaming about geese (or swans or ducks or something) and all of the people turned into birds and flew away. The end.