INP Specification

INP Stands for Inochi2D Puppet, and is a binary container format to contain Inochi2D model, texture and extra data.

INP is subject to change as we get closer to the 1.0 release.

Format Layout

Note

Inochi2D stores values in Big Endian format, please make sure you handle this correctly!

You can find out more about endianness here.

Length (bytes)	Contents	Notes
8	TRNSRTS\0	Magic bytes which tag the file as an INP file. (Trans Rights!)
4	JSON Payload Length	Length of JSON Payload
Payload Length	JSON Data	The Inochi2D model and rigging data
8	TEX_SECT	Texture Section Header
4	Texture Count	Amount of textures in the texture section
Till Texture Blob End	Texture Blob	Contains a texture and tag denoting what type the texture is.
8	EXT_SECT	OPTIONAL: Header for extended vendor data section
4	Payload Count	IF EXT_SECT EXISTS Amount of payloads that are in this section
Till EXT Section End	EXT Section Blob	IF EXT_SECT EXISTS The 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	A byte defining what texture encoding is in use. See Texture Encoding section.
Payload Length	Texture Data	Encoding of data depends on previous type

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	Contents of payload, encoding is up to the individual developer.

Texture Encoding

There’s 3 currently officially supported 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)