To convert from .png simply enter it as the input file, like so:
This will convert it to a .pngb. If you want to convert to .tgab, add "-t" to the end:
By the way, remember you can specify a folder and it will convert all the compatible files in there:
So you don't need a batch script.
As for those unsupported files, they are in a different format, although it's not the same unsupported format as found in the first samples you sent. Unfortunately they are just as confusing (if not more so), I'm unsure how they work. Even the data for the dimensions seems to be stored differently.
One big issue is for both this and the other unsupported format, the number of bytes in the pixel data divided by width * height (which is number of pixels) is a decimal, while the working format gives 4 (it's raw 32-bit ARGB). This means that the other formats probably have some sort of compression, maybe RLE or the like (since it doesn't look like any kind of zlib/lz/zip/etc compression).
I don't have a lot of time for it, but I
might try and take a better look when I do. Are there are a lot of unsupported files?