As AlexShumi and Jayjay57 said to you: Use Slimtex (ZAZTools),click on the "batch to tex" tab. Then select your tga files (select them and drag into the slimtex window).Once your tga files are in the slimtex window, select them all, click-right and choose:
-Image format: DXT5
-Transparency type (full or semi)
-width and height (if not mentionned)
-Numbers of mipmaps = 4
-Flip
and click on "Convert"
It's done.
PS: If you just got the tex files, same procedure, click and drag your tex files into the slimtex window (batch to tex), just flip and convert.
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