This format is somewhat analogous to UTF-8.

1VVVVVVV 1WWWWWWW 1ZZZZZZZ 1YYYYYYY 0XXXXXXX → 0bVVVVVVVWWWWWWWZZZZZZZYYYYYYYXXXXXXX.

1WWWWWWW 1ZZZZZZZ 1YYYYYYY 0XXXXXXX → 0bWWWWWWWZZZZZZZYYYYYYYXXXXXXX.

1ZZZZZZZ 1YYYYYYY 0XXXXXXX → 0bZZZZZZZYYYYYYYXXXXXXX.

Uintvar is a variable length encoding for unsigned integers, with following rules: So sequence of bytes 01 00 00 means 65536. Int24be and uint24be are big-endian (that is reversed) 24 bit (3 byte) signed and unsigned integer.

Neither string format is ever zero-terminated.īefore I get to the format itself, there are a few exotic encodings used in ESFs.

There are no observed instances of 0 character/codepoint being present in either of them. There are no observed instances of Unicode planes other than Basic Multilingual Plane being used. There are no observed instances of ASCII strings having high bit set - so it's not possible to tell if that's meant as ISO-Latin-1, UTF-8, an error, or something else. There are two kinds of strings used in ESF files - ASCII strings (used mostly for internal identifiers), and Unicode strings (used mostly for displayable text).īoth are prefixed by character count as uint16, for ASCII strings ( ca_ascii):

bool8 - boolean ( 00 false, 01 true, other values never observed).

char16 - little-endian UTF- 18 codepoint.

float32, float64 - single and double precission IEEE 754 floating point numbers.

uint8, uint16, uint32, uint64 - little endian unsigned integers.

int8, int16, int32, int64 - little-endian signed integers.

Most of data types used in ESFs are straightforward - almost everything is little endian unless noted otherwise, data sizes are standard powers of two, negative numbers are two's-complement, character set is Unicode, floating point numbers are IEEE 754 etc. This post is meant to be such documentation. It was reverse engineered from partial documentation by various people including your truly, but so far there's no complete documentation available anywhere. ESF is the primary data format used by Total War series games starting from Empire, and then Napoleon, Shogun 2, and whatever comes next.

Esf editor empire total war