Okay, by "frame length" I totally misunderstood and thought it meant the number of frames per animation as opposed to display time length.
Let's examine some code. Here's Crono's animation data:
00243000 03 FF 00 00 16 17 18 19 - 1A 1B FF 00 C6 4F C7 4F
00243010 FF 00 00 00 64 FF 00 00 - 20 41 21 22 42 23 FF 00
00243020 45 FF 00 00 6E FF 00 00 - 4F 3A 39 38 6C 6D FF 00
00243030 38 39 3A 4F FF 00 00 00 - 49 8D 8E 49 FF 00 00 00
00243040 71 72 71 72 71 FF 00 00 - 47 48 FF 00 00 FF 00 00
00243050 00 00 00 00 2C 6C FF 00 - 03 93 FF 00 97 03 98 03
00243060 FF 00 00 00 A5 FF 00 00 - CC CD FF 00 68 69 6A 6B
00243070 FF 00 00 00 47 FF 00 00 - 7C FF 00 00 7B FF 00 00
00243080 79 FF 00 00 00 9F A0 FF - AC AD FF 00 87 FF 00 00
Crono's first two animations are highlighted. So, the FF byte is a termination instruction and any 00 bytes that follow serve as buffers to ensure the next animation begins at a multiple of four. Am I correct on that guys?
Given that this is correct, now for another question -- in the above example with Crono, I think the red animation is "standing-front." If so, is the byte 03 telling the game engine to call up the third frame in Crono's sprite assembly? (or would it actually be the fourth frame, with 0x00 representing the first frame?)