>> There's also some fun with different frame types. 
> 
> That's the main place the ambiguities come from. If you don't understand 
> the ways in which you can build a B-frame, you're not going to see where 
> you can get good quality at low bitrates for video with things moving.
> 
> MPEG1 had motion prediction too. It's just that the CPU power needed to 
> do it never got cheap before MPEG2 came out.

I know that MPEG has several different kinds of frames, some of which 
are individual, independent frames, and some of which are related to 
previous frames. I can just never remember the exact details; every 
reference on the subject that I've ever read has made it sound insanely 
complex, when obviously it isn't.

> Back in 1991 or so, I worked with someone who encoded 6 minutes of Star 
> Wars as MPEG1 for testing video on demand. They sent it out to a place 
> that had a specially-built cluster of machines for doing this work, and 
> it took several CPU weeks.  (This was in the same timeframe where doing 
> jpeg compression needed special hardware cards in a PC, to the point 
> where it was faster to ship the image to the PC with the card, compress 
> it, and ship the results back, than it was to do in software.)

Damn. And here I was thinking an integer-arithmetic FFT would be really 
fast...

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