Basically this should be a list comprising of
Codec Name, Patent Numbers, Patent Owners, Patent Expiry

AMR-NB
AMR-WB/G.722.2
G.722.1,
G.723.1,,(DSPG, Audiocodes, France Telecom, University of Sherbrooke, NTT of Japan,AT&T,Lucent)
G.726,
G.728,
G.729, US#5664055, Lucent
G.729.1,
GSM,
SPEEX,