Fix out of tree builds
Fix out of tree builds

jiangjianping/vo-amrwbenc,mstorsjo/vo-amrwbenc,Distrotech/vo-amrwbenc,Distrotech/vo-amrwbenc,BelledonneCommunications/vo-amrwbenc,Distrotech/vo-amrwbenc,mstorsjo/vo-amrwbenc,jiangjianping/vo-amrwbenc,BelledonneCommunications/vo-amrwbenc