fourcc dx 10 name             description alpha premultiplied              compression ratio        texture type
0   dxt1        bc1  1 - bit alpha / opaque               n / a  6:1 (for 24 bit source image)  simple non - alpha
1   dxt2     (none)          explicit alpha                 yes                            4:1         sharp alpha
2   dxt3        bc2          explicit alpha                  no                            4:1         sharp alpha
3   dxt4     (none)      interpolated alpha                 yes                            4:1      gradient alpha
4   dxt5        bc3      interpolated alpha                  no                            4:1      gradient alpha

Table as JSON:
{"fourcc":{"0":"dxt1","1":"dxt2","2":"dxt3","3":"dxt4","4":"dxt5"},"dx 10 name":{"0":"bc1","1":"(none)","2":"bc2","3":"(none)","4":"bc3"},"description":{"0":"1 - bit alpha \/ opaque","1":"explicit alpha","2":"explicit alpha","3":"interpolated alpha","4":"interpolated alpha"},"alpha premultiplied":{"0":"n \/ a","1":"yes","2":"no","3":"yes","4":"no"},"compression ratio":{"0":"6:1 (for 24 bit source image)","1":"4:1","2":"4:1","3":"4:1","4":"4:1"},"texture type":{"0":"simple non - alpha","1":"sharp alpha","2":"sharp alpha","3":"gradient alpha","4":"gradient alpha"}}