sox and GSM

On the sox site it looks like sox 12.17.4 should support the GSM file format. However, sox -h doesn't reveal gsm support. Presumably because of the claims of Phillips against it from the little reading I've done. The man page indicates that the GSM support is optional and requires an external GSM library. Is this external library needed at compile time or runtime? Is there an rpm of sox for SuSE 9.0 which supports GSM? I thought I'd check before I go through the steps of finding the library and trying to build from source. -- -M There are 10 kinds of people in this world: Those who can count in binary and those who cannot.