A tough nut to crack.

[Derelict Coin-op]

Hello all,long time site goer,new to the forums though. There's a short film I watched long long ago. Maybe back in the 90's I was maybe 7 or so and I watched it at the library of all places. Though the short itself may have been from even earlier I don't know. It was about this city of people who live in this guys dreams,and the person is always kept asleep and if he wakes the city will disappear. It was animated for sure and in black and white I think? Black and white is up for debate. And in the end all the people in the city turn into hundreds of flamingos and fly off out of the guys imagination. I have been trying to find this film or at least remember for years and years. If anyone has any clue or any ideas at all it would be beyond awesome. Now that I think of it, it may have been a part of a compilation of shorts. Thanks guys. 

[Rayo Casablanca]

That's a UK animated film called RARG (1988). Was on PBS among other places though a VHS exists.
http://www.toonhound.com/rarg.htm

[Derelict Coin-op]

Sweet Jesus,thanks you! That's the one! I'm going to have to try and find it and buy it now. I can't believe someone actually found it. Much respect.