SCEX

Position	Length	Type	Description
0x00	0x04	string	Identifier (SCEX)
0x04	0x04	uint	Size in bytes
0x08	0x04	string	Scene name?
0x0C	0x04	uint	Size in bytes (relative to 0x08)

TRCK

https://tcrf.net/Shenmue/Source_Code#.5CSCENE.5C99.5CMS08.5CSEQCONV.C
A track contains information for an cutscene.
The track segment has no data itself, it just contains all the child segments which do contain the data.

Position	Length	Type	Description
0x00	0x04	string	Identifier (TRCK)
0x04	0x04	uint	Size in bytes

ASEQ

Position	Length	Type	Description
0x00	0x04	string	Identifier (ASEQ)
0x04	0x04	uint	Size in bytes
0x08	0x01	byte	Endianness (0 - Little, 1 - Big)
0x09	0x01	byte	Version (5 is most commonly found in S1 - 7 in S2)
0x10	0x01	byte	Reserved
0x11	0x01	byte	Reserved
0x12	0x04	int	Num Frames

Table of content entry (12 bytes)

Position	Length	Type	Description
0x00	0x01	byte	Flag?
0x01	0x01	byte	Flag?
0x02	0x02	?	Reserved?
0x04	0x04	string	Character name and other stuff (props?)
0x08	0x04	uint	Index

ACAM

Probably camera animation.