Flipnote Files

*.ppm FILES

Start	Length	Description
0x0000	4	Magic (should be PARA)
0x0004	4	Size of animation-section
0x0008	4	Offset 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	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	Mirrored author ID ??
0x0092	8	Partial File name? - see notes on format
0x009A	6	Unknown - possibly date information
0x00A0	1536	Preview Bitmap (4 bits/pixel).

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

Palette:

Hex	Color
0x0	??
0x1	Dark grey
0x2	White
0x3	Light grey
0x4	Light red
0x5	Dark red
0x6	Pink
0x7	Pure green
0x8	Pure blue
0x9	Purple
0xA	Light blue
0xB	Pure green
0xC	Magenta
0xD	Pure green
0xE	Pure green
0xF	Pure green

The preview image is a 64x48 image stored in a 16 colour tile way, with each 8x8 tile taking up 32 bytes of the file. Here's two preview images I (blasty) decoded from some PPM files.