NAS

A .NAS file is a compressed paletted image archive format. The format appears to be proprietary and specific to the Bunny Pro. Das2 visual novel software for Windows.

Specification

• This format has the signature 4E 41 00 00
• Payload-size (int)
• A fixed-size palette of 256 entries totalling 768 bytes. Each entry is a 3-byte tuple for the red, blue and green component. (Most images do not use all 256 entries but the palette is always 768 bytes)
• A series of chunks, either starting with the bytes AD or NB. Most images only have a single NB chunk.

NB chunk

The **NB** chunk contains image data and has the following format:

- Signature (ND) - Image width (short) - Image height (short) - `unknown1` (short) — usually 0 or 1 - `unknown2` (short) — always 0 - `unknown3` (short) — always 1 - Length of data (int) - Image data

The image data is compressed and the method is unknown.

AD chunk

The format of this chunk is unknown:

• Signature (AD)
• Data (362 bytes)