CTPK - CTR Texture PacKage
CTPK is a container file for one or multiple textures that are in various formats readable by the 3ds system. Offsets are relative to the beginning of the header section unless specified.
CTPK Header #
| Offset | Length | Description |
|---|---|---|
| 0x0 | 0x4 | Magic “CTPK” |
| 0x4 | 0x2 | Version? |
| 0x6 | 0x2 | Number of Texture Entries |
| 0x8 | 0x4 | Texture Data section offset |
| 0xC | 0x4 | Texture Data section size |
| 0x10 | 0x4 | Hash section offset |
| 0x14 | 0x4 | Conversion Info section offset |
| 0x18 | 0x8 | Padding |
Texture Info Entry #
The Header block is followed by a texture info entry for each texture in the container. This block is usually followed by the bitmap size arrays and then the file paths. 0x20 byte aligned.
| Offset | Length | Description |
|---|---|---|
| 0x0 | 0x4 | File path Offset |
| 0x4 | 0x4 | Texture Data Size |
| 0x8 | 0x4 | Texture Data Offset (Relative to texture data block offset) |
| 0xC | 0x4 | Texture Format |
| 0x10 | 0x2 | Width |
| 0x12 | 0x2 | Height |
| 0x14 | 0x1 | Mip Level |
| 0x15 | 0x1 | Type (0: Cube Map, 1: 1D, 2: 2D) |
| 0x16 | 0x2 | Cube Map Related |
| 0x18 | 0x4 | Bitmap Size Array Offset (Relative to to this block) |
| 0x1C | 0x4 | Unix Timestamp |
Hash Block Entry #
The texture info block is followed by a hash entry for each texture entry. 0x8 byte aligned.
| Offset | Length | Description |
|---|---|---|
| 0x0 | 0x4 | Crc32 of the file path |
| 0x4 | 0x4 | Index |
Conversion Info Block Entry #
The hash block is followed by a conversion info entry for each texture entry. 0x4 byte aligned.
| Offset | Length | Description |
|---|---|---|
| 0x0 | 0x1 | Texture Format |
| 0x1 | 0x1 | Unknown |
| 0x2 | 0x1 | Compressed |
| 0x3 | 0x1 | ETC1 Related (Quality?) |
Texture Data Block #
This block and all it’s texture entries are 0x80 byte aligned.
Texture Formats #
| Value | Description |
|---|---|
| 0x0 | RGBA8888 |
| 0x1 | RGB888 |
| 0x2 | RGBA5551 |
| 0x3 | RGB565 |
| 0x4 | RGBA4444 |
| 0xC | ETC1 |
| 0xD | ETC1 + Alpha |