It looks like MP1 has 32 subbands and works on 12 samples each, which results in a frame size of 384. MP2 works on 3 groups of 12 samples for each subband, resulting in 1152 samples.
Of course this just punts it to the question of why 32, 12, and 3? To which I can only answer: quick, look behind you! <runs away>
At least the mystery numbers are smaller.
But seriously, I'm at (beyond) the limits of my understanding of this stuff, so if anyone with more knowledge would care to chime in and explain those, I'd be most interested to know.
I mean, good point. I dug a bit farther and found this document which discusses the design in some detail:
https://web.archive.org/web/20040919073530/http://www.cs.col...
It looks like MP1 has 32 subbands and works on 12 samples each, which results in a frame size of 384. MP2 works on 3 groups of 12 samples for each subband, resulting in 1152 samples.
Of course this just punts it to the question of why 32, 12, and 3? To which I can only answer: quick, look behind you! <runs away>
At least the mystery numbers are smaller.
But seriously, I'm at (beyond) the limits of my understanding of this stuff, so if anyone with more knowledge would care to chime in and explain those, I'd be most interested to know.