I tried all the way I founded but not working.
First I download bcg729 project to build file libbcg729.a
I followed instruction here : https://trac.pjsip.org/repos/ticket/2029
But when I run TARGET_ABI=armeabi-v7a ./configure-android --use-ndk-cflags --with-bcg729=/Users/bienpx224/Desktop/bcg729
and then checkbcg729 usability.... no
-> wrong
Second I tried follow that to build pjsip project with a patch of bcg729.
Link instruction : http://saravnandm.blogspot.com/2016/07/pjsip-25-g729-codec.html
But checking bcg729 disable.... yes
-> wrong
So someone can help me the tutorial to build PJSIP support bcg729 for Andoird. Thanks you so much.