INP Data Interchange Format

INP

INP stands for Inochi Puppet, and is a VRM/glTF like format for interchanging Inochi2D puppet data.
Note: As new features are added to Inochi2D this format is subject to change.

Format Layout

Note: All numbers are encoded in Big Endian.

Length (bytes)	Contents	Notes
8	TRNSRTS\0	The magic bytes for an INP file, these need to be there to tell the INP loader that it's an INP file. (Trans Rights!)
4	JSON Payload Length	Length of the JSON Payload
Payload Length	JSON Data	The internal JSON data that contains all the model data.
8	TEX_SECT	Texture Section header
4	Texture Count	The amount of textures stored in the Texture Section
Till Texture Blob End	Texture Blob	The texture blob section contains the texture blobs for this puppet ordered after their texture ID.
8	EXT_SECT	(OPTIONAL) Optional EXTended Vendor Data section for app provided settings for the puppet.
4	Payload Count	(If EXT exists) Amount of JSON payloads that are in this EXT section.
Till EXT Section End	EXT Section Blob	(If EXT exists) The EXT section blob of this EXT section

Texture Blob

Every Texture entry in the Texture Blob have the following encoding

Length (bytes)	Contents	Notes
4	Texture Payload Length	Length of the Texture Payload
1	Texture Encoding Type	A byte defining what texture encoding is in use. See Texture Encoding section.
Payload Length	Texture Data	Texture Data

EXTended Vendor Data Blob

Length (bytes)	Contents	Notes
4	Name Length	Length of EXT Payload name
Name Length	Name	The name of the EXT payload
4	Payload Length	Length of the EXT payload
Payload Length	Payload	The JSON contents of the EXT Payload

Texture Encoding

There's 3 supported texture formats in Inochi2D, which are the following:

ID	Format
0	PNG - Portable Network Graphics (Lossless)
1	TGA - Truevision TGA (Lossless)
2	BC7 - BPTC Texture Compression (Lossy)