Codec failover?

Hey everyone, just wondering is there a way to have codec failover if I run out of G729 licenses ?? I am doing this between asterisk and my provider. Local lan traffic is Ulaw. I enabled G726 and G729 on the siptrunk config however, I am getting an error msg
"Dec 12 17:29:42 WARNING[19431]: codec_g729.c:173 g729tolin_framein: Out of G.729 Decoder Licenses!"
It doesn't seem to rollover to G726 when it runs out of licenses ?? I'm assuming since when the call is placed asterisk has no idea its out of licenses until the call is connected. Any help would be appreicated.
"Dec 12 17:29:42 WARNING[19431]: codec_g729.c:173 g729tolin_framein: Out of G.729 Decoder Licenses!"
It doesn't seem to rollover to G726 when it runs out of licenses ?? I'm assuming since when the call is placed asterisk has no idea its out of licenses until the call is connected. Any help would be appreicated.