VLC has support for BISS natively,so my guess is TSreader wrap the command line to VLC using the key embedded in it.
I doubt he added a CSA decoder into TSreader.
But anything is possible
It is the same method as before,using a plugin to decode biss.
Nothing new,you could decode biss with TSreader using any capable plugin (biss.dll) since the first version plugins support was introduced.