For Unix Systems

You can use the tool on macOS (10.15 or later) and Ubuntu (20.04 or later).
The steps are as follows.

1. Download the git repository

Download the git repository as a zip file. (Code -> Local -> Dowload ZIP)
And unzip it.

2. Remove unnecessary files

Open UE4-DDS-Tools-main.
Then, remove .github, bat, external, .gitignore, .gitmodules, and gui_definition.json.

3. Rename .json file

Rename gui_definition_unix.json to gui_definition.json.
The json file is the gui definition for unix builds.

4. Download Simple Command Runner

Download SimpleCommandRunner-v0.2.1-*.tar.bz2 from here.
Then, copy the executable (SimpleCommandRunner) to UE4-DDS-Tools-main.
It's a Unix build for GUI.exe.

5. Allow executing file as program (for Ubuntu)

If you are using Ubuntu, you should check Allow executing file as program. (Properties->Permissions->Execute)

6. Download Shared Library (Texconv)

Download blender_dds_addon_v0.2.0_*.zip from here.
Then, copy the shared library (blender_dds_addon/directx/libtexconv.*) to UE4-DDS-Tools-main\src\directx.
It's a Unix build for the DDS converter.

7. Install Python3.x

Unix versions will use python3 to run python scripts.
Install it if you don't have.

8. Done!

Run SimpleCommandRunner.
It'll show the same GUI as the Windows version.

If you get a macOS cannot verify that this app is free from malware warning, you should allow Mac to open the file.
You can find tons of websites that explain how to fix it.

Notes

Please note that the Unix versions have some limitations.

• .png, .jpg, and .bmp are unavailable.
• BC6 and BC7 compression will take tons of times because the Unix builds can't use GPU.