Encoder don’t support BlockBased compression formats (DXT1, ETC1, PVRTC) due to lack of available source code

[makc]

Doesn't https://github.com/adobe/dds2atf have that code?

[plepers]

DDS files already contains those texture formats. dds2atf extract them from dds to write them back to atf, making some additional work like pixel format conversions, lzma & jpegxr compression.

The second problem is that image datas in blockbased formats are internaly compressed using jpegXr with a pixel format unsupported by native flash jpegxr encoder ( 16bppBGR555 and 16bppBGR565). So to achieve BB compression we'll need to port jpegxr encoder to as3...

[makc]

A ha, well then, it's time to rape the google :) For example, for DXT1 encoder I've found http://code.google.com/p/crunch/ (linked from http://lspiroengine.com/?p=260 where it seems to be some interesting code dscussion)

[plepers]

I've started to implement DXT encoding (the simple way), based on http://code.google.com/p/libsquish/

But i can't go further without BGR565 / 555 option in jxr encoder :(

Its a wip but I can push it to repo if you want to take a look.

[makc]

16bppBGR555 and 16bppBGR565 are both mentioned in https://github.com/adobe/dds2atf/blob/master/3rdparty/jpegxr/jpegxr_pixelformat.cpp so there's a chance it is implemented there )

[makc]

some public domain code http://nothings.org/stb/stb_dxt.h