Inconsistancy.  The number of frames per region is not constant.
 1          1         45

 1          1         45

 1       4488          1         13         25         37
 1       4489          2         14         26         38
 1       4490          3         15         27         39
 1       4402          4         16         28         40
 1       4401          5         17         29         41
 1       4309          6         18         30         42
 1       4310          7         19         31         43
 1       4214          8         20         32         44
 1       4213          9         21         33         45
 1       4212         10         22         34
 1       4308         11         23         35
 1       4400         12         24         36