Package: libtxc-dxtn-s2tc-bin

"libtxc-dxtn-s2tc-bin" package binaries on Debian:

/usr/bin/s2tc_compress /usr/bin/s2tc_decompress /usr/bin/s2tc_from_s3tc

You may install this package on Debian with apt-get install libtxc-dxtn-s2tc-bin