Java Edition Indev level format

The .mclevel map format is a new map format, created by Notch. It is based on the NBT 2 format.

A basic example can be seen here 1, a more up-to-date one comes below.

Data
The Data byte array is used for lighting and extra block data. The first 4 bit contains the extra block data and the other 4 bits the lighting.

The following blocks use extra data:

Farmland
0x0 is dry land, 0x1 and above is wet. The wetness value depends on how far the block is away from water.

Crops
Crops grow from 0x0 to 0x6.



Torches
Torches use the data to determine their state.

0x0 is the basic straight torch. 0x1 to 0x4 are the torch sticking into a nearby block.