main: blocksizes
      0      0      0      1
      0      0    315   1981
      0    315      0   9576
      1   3017   9576  24678
-------------------------------------------------------------------
       cpt   T1E6   A1D6  split
cpt      0      0      0      1
T1E6     0      0    315   1981
A1D      0    315      0   9576
split    1   3017   9576  24678