G729 codec install

thanks…
i think i better install the opensource g729 for transcoding.
but i can’t find any guide…
can you please help me? i am using astpp version 4
i found one in github but its says i need to locate this

FS_INCLUDES=/usr/include/freeswitch

when we install astpp where is the FS_INCLUDES location? as i can find anything on /usr/include/freeswitch

thanks