sudofox's journal

Austin Burk's journal, where I share little snippets of my writing, code, and dreams.

Some notes about Flipnote Hatena's .nbf background format

We're working on the nbf top-screen background format used on Flipnote Hatena.


We're making some progress.

The nbf files appear to be composed of three sections. Hatena seems to have reused what I call the ugomenu format; which is also used for the menus on Flipnote Hatena. The first 0x16 bytes of any ugomenu usually contains:

  1. 0x4 -The ugomenu magic ("UGAR").
  2. 0x4 32-bit little-endian unsigned integer specifying the number of sections within the container.

After this, for however many entries specified above: 0x4 uint32 LE specifying the length of each entry.

For the nbf files, this header totals 0x16 bytes.

After the header comes palette data, and after that, a bitmap image. What we're currently trying to do is convert the palette to a format that TiledGGD likes; however, we're not quite there yet.

If I remember correctly, the image displayed above, both on the left, and the representation on the right is the art of id:chira_rhythm55, the Flipnote Hatena theme artist. 

I eventually hope to be able to create custom images and convert back and forth between the .nbf format and a regular image format, such as PNG.

Have a nice day, and thank you for reading :)