Flipnote Files/PPM

Start	Length	Description
0x0000	4	Magic (should be PARA)
0x0004	4	Size of animation data
0x0008	4	size of audio data
0x000C	2	# of frames
0x000E	2	Unknown - all files looked at so far has this field set to 24 00 hex.
0x0010	2	Is locked? - 0 open, 1 locked
0x0012	2	Preview frame number
0x0014	22	Original author name (UCS-2)
0x002A	22	Last Edited By Author name (UCS-2)
0x0040	22	User name (UCS-2)
0x0056	8	Original author ID
0x005E	8	Edit Author ID - the last user to save the file
0x0066	18	Original File-name - see notes on format
0x0078	18	File-name - see notes on format
0x008A	8	Previous Editing Author ID
0x0092	8	Partial File name? - see notes on format
0x009A	6	Unknown - possibly date information
0x00A0	1536	Preview Bitmap (4 bits/pixel).
0x06A0	8 + ( 4 * Number of frames)	Animation Sequence Header

The file name seems to be stored in the file header 3 times:

• Original file name 0x0066
• Current file name 0x0078
• Partial file name 0x0092

The file name is stored in 3 parts:

• 3 hex bytes, the first byte's high nibble is not the same as the first byte of the file name
• 13 bytes for the central part of the file name
• 2 bytes for the last part of the file name.

For the file name : G35B20_0909841CDBEB1_002

• First location: D3 5B 20 30 39 30 39 38 34 31 43 44 42 45 42 31 00 00
• Second location: D3 5B 20 30 39 30 39 38 34 31 43 44 42 45 42 31 02 00
• Last location: D3 5B 20 09 09 84 1C DB

The 3 sections of the file name seem to be stored as:

• Last 6 digits of your Flipnote Studio ID
• A random number, possibly generated from a date stamp
• The version number of the file

Palette

Hex	Color	DS RGB Approximation
0x0	Not used / White	31, 31, 31
0x1	Dark Grey	10, 10, 10
0x2	White	31, 31, 31
0x3	Light Grey	20, 20, 20
0x4	Pure Red	31, 0, 0
0x5	Dark Red	15, 0, 0
0x6	Light Red / Pink	31, 15, 15
0x7	Pure Green	0, 31, 0
0x8	Pure Blue	0, 0, 31
0x9	Dark Blue	0, 0, 15
0xA	Light Blue	15, 15, 31
0xB	Pure Green	0, 31, 0
0xC	Magenta / Purple	31, 0, 31
0xD	Pure Green	0, 31, 0
0xE	Pure Green	0, 31, 0
0xF	Pure Green	0, 31, 0

The preview image is a 64x48 image stored in a 16 colour tile format, with each 8x8 tile taking up 32 bytes of the file.

Here's a photo taken of the altered preview image, reduced to about the correct size.

Link to the original picture, warning image is 2,048 × 1,536.

Here's two preview images that blasty decoded from some PPM files.