Need help with the ETC texture type

[slbidd]

Hello, I'm sorry to bother you. My English is not very good, and I am currently using translation software. It's like this, I'm trying to unpack the mpkg file, which is the wallpaper file for Wallpaper mobile version. I encountered some issues while unpacking the tex file. I have only learned a little Python, and C # is a bit difficult to understand. However, I still browsed through your C # source code and found that in the texture type, 0=>ARGB8888, 4=>DXT5, 6=>DXT3, 7=>DXT1, 8=>RG88, 9=>R8. However, the texture type of this file is 05, so the program threw an exception. I don't know which texture format this is, but after researching,** I speculate it's ETC2. But I don't know how this texture format is encoded, **so I would like to ask where you can find relevant information. Look forward to your reply with the least possible delay.