tex2img 0.8.2

a texture decompression C++-extension for Python

tex2img

A texture decompression C++-extension for Python.

1. Installation
2. Notes
3. Functions
4. Sources

Installation

pip install tex2img

or download/clone the git and use

python setup.py install

Notes

• Crunch isn't supported on Mac OS. (There is no equivalent for malloc_useable size.)
• decompress_pvrtc seems to have some kind of problem on Mac OS. Mac users might have to use basisu_decompress instead.
• decompress_etc has a memory leak. The etc unpacking via basisu_decompress works fine tho.

Functions

All functions accept only args and aren't able to handle kwards atm.

basisu_decompress

Decompresses data to RGBA via basisu's unpack_block function.

Args: (compressed data: bytes, width: int, height: int, format: int)

Returns: bytes

Formats:

Format	Mode	Note
0	cETC1	ETC1
1	cETC1S	ETC1(subset:diff colors only, no subblocks)
2	cETC2_RGB	ETC2 color block
3	cETC2_RGBA	ETC2 alpha block followed by ETC2 color block
4	cETC2_ALPHA	ETC2 EAC alpha block
5	cBC1	DXT1
6	cBC3	DXT5(DXT5A block followed by a DXT1 block)
7	cBC4	DXT5A
8	cBC5	3DC / DXN(two DXT5A blocks)
9	cBC7
10	cASTC4x4
11	cPVRTC1_4_RGB
12	cPVRTC1_4_RGBA
13	cATC_RGB
14	cATC_RGBA_INTERPOLATED_ALPHA
15	cFXT1_RGB
16	cPVRTC2_4_RGBA
17	cETC2_R11_EAC
18	cETC2_RG11_EAC

decompress_astc

Decompresses raw astc-compressed data to RGBA.

Args: (compressed data: bytes, image width: int, image height: int, block_width: int, block_height: int, isSRGB: False)

Returns: bytes

decompress_atc

Decompresses raw atc-compressed data to RGB(A).

Args: (compressed data: bytes, width: int, height: int, alpha: bool)

Returns: bytes

alpha = False for ATC_RGB alpha = True for ATC_RGBA

decompress_pvrtc

Decompresses raw pvrtc-compressed data to RGBA.

Args: (compressed data: bytes, width: int, height: int, do2bit_mode: 0)

Returns: bytes

decompress_etc

Decompresses raw etc-compressed data to RGB(A).

Args: (compressed data: bytes, width: int, height: int, format: int)

This function has a memory leak, so it might crash if you use it on too many images at once (~500+). The basisu_decompress function also supports the most common ETC formats, so it is a good alternative.

Formats:

Format	Mode
0	ETC1_RGB_NO_MIPMAPS
1	ETC2PACKAGE_RGB_NO_MIPMAPS
2	ETC2PACKAGE_RGBA_NO_MIPMAPS_OLD
3	ETC2PACKAGE_RGBA_NO_MIPMAPS
4	ETC2PACKAGE_RGBA1_NO_MIPMAPS
5	ETC2PACKAGE_R_NO_MIPMAPS
6	ETC2PACKAGE_RG_NO_MIPMAPS
7	ETC2PACKAGE_R_SIGNED_NO_MIPMAPS
8	ETC2PACKAGE_RG_SIGNED_NO_MIPMAPS
9	ETC2PACKAGE_sRGB_NO_MIPMAPS
10	ETC2PACKAGE_sRGBA_NO_MIPMAPS
11	ETC2PACKAGE_sRGBA1_NO_MIPMAPS

crunch_get_texture_info

Retrieves texture information from the CRN file.

Args: (data: bytes)

Returns: dict

crunch_get_level_info

Retrieves mipmap level specific information from the CRN file.

Args: (data: bytes, mipmap_leve: int)

Returns: dict

crunch_unpack_level

Transcodes the specified mipmap level to a destination buffer.

Args: (data: bytes, mipmap_level: int)

Returns: bytes

Sources

ATC & ASTC

The complete BinomialLLC/basis_universal is used and supported. It's default for the ATC and ASTC decompression.

ETC

The whole source of Ericsson/ETCPACK is used for the ETC decompression.

PVRTC

PVRTDecompress.cpp and PVRTDecompress.h of powervr-graphics/Native_SDK are used for the PVRTC decompression.

crunch

A mixed version of BinomialLLC/crunch and Unity-Technologies/crunch is used.

The Unity fork doesn't yield correct results for the original modes, so the BiomialLLC version is used for all modes besides ETC, which was created byUnity.