LMS > File Format Overview
This page describes the general structure of files loaded by the LMS library. The files start with a header which is followed by different kinds of blocks. All blocks are aligned to 16 bytes. The space between two blocks is padded with 0xAB bytes.
The following file formats are used by LMS:
File Header
| Offset | Size | Description |
|---|---|---|
| 0x0 | 8 | Magic number |
| 0x8 | 2 | Endianness (0xFEFF=Big, 0xFFFE=Little) |
| 0xA | 2 | Unknown (always 0?) |
| 0xC | 1 | Message encoding (0=UTF-8, 1=UTF-16, 2=UTF-32) |
| 0xD | 1 | Version number |
| 0xE | 2 | Number of blocks |
| 0x10 | 2 | Unknown (always 0?) |
| 0x12 | 4 | Filesize |
| 0x16 | 10 | Padding |
Block Header
| Offset | Size | Description |
|---|---|---|
| 0x0 | 4 | Block type |
| 0x4 | 4 | Block size (without header) |
| 0x8 | 8 | Padding |
| 0x10 | Block data |
Hash Tables
Many items (such as messages in msbt files or colors in msbp files) are looked up by label. The labels are looked up with a hash table and are stored in a different block than the items themselves. In official files the hash table always has a fixed number of buckets (101 in msbt files, 29 in msbp files), even if it contains only a few labels.
The following hash algorithm is used:
def calc_hash(label, num_buckets):
hash = 0
for char in label:
hash = hash * 0x492 + ord(char)
return (hash & 0xFFFFFFFF) % num_buckets
The block with the labels contains the following data:
| Offset | Size | Description |
|---|---|---|
| 0x0 | 4 | Number of buckets |
| 0x4 | 8 per bucket | Hash table buckets |
| Labels |
Hash Table Bucket
| Offset | Size | Description |
|---|---|---|
| 0x0 | 4 | Number of labels |
| 0x4 | 4 | Offset to labels |
Label
| Offset | Size | Description |
|---|---|---|
| 0x0 | 1 | Length of label string |
| 0x1 | Label string (without null terminator) | |
| 4 | Item index |