[PS2] EyeToy: Play .ETI textures

[Thatonebruh196]

Looking for help on figuring out how to decode the texture files for EyeToy: Play, they're ".ETI" files, below I've linked all the textures for Kieu as an example.

Kieu textures.rar

[piken]

Some partial investigation:

• 50h, 52h - width and height
• D8h - palette and pixel data in 8-bit PS2 address-swizzled layout at a width of 128.

//--------------------------------------
//--- 010 Editor v6.0.3 Binary Template
//
// File:
// Author:
// Revision:
// Purpose:  EyeToy .ETI files
//--------------------------------------

LittleEndian();

typedef uchar uint8;

typedef struct {
    uint8 header[4] <bgcolor=0x0080FF>;
    uint32 unknown <format=hex>;
    uint32 fileSize <format=decimal, bgcolor=0x0040FF>; // Full size, including this field and the preceding bytes.
    uchar fileName[0x44] <bgcolor=0x00D000>;
    uint16 width <bgcolor=0xFFD000>;
    uint16 height <bgcolor=0xFFD800>;
    uchar unknown2[0x84];
} EtiHeader;

EtiHeader etiHeader;

// D8h begins the palette and address-swizzled PS/2 pixel data.
uint8 graphData[etiHeader.fileSize - sizeof(EtiHeader)] <bgcolor=0x00FFFF>;

Then if you start from D8h and unswizzle the 8-bit data, you get the palette and pixels as 32x32 tiles, with the first 32x32 tile (1024 bytes = 256 entries x 4 bytes) being the palette and following tiles being graphics.

Remaining steps (for you or others to figure out, or me if I have time and motivation later):

• Palette data - it's clearly 32-bit data with FF for full alpha (not 80h like native PS2 palettes), but what is the color entry order?
• Graphics data - where are the tile indices stored to unscramble the data?

Manually rearranging the data via Aseprite, we get Kieu's winking face:

But as you know, the colors should look like: