[Freeswitch-users] writing to mp4 file not work

   Hi, I setup FreeSWITCH 1.6 on Debian Jessie using the apt-get modules. I have mod_av auto loaded.  When I try to "auto-record" to record to a mp4 file in /etc/freeswitch/autoload_configs/conference.conf.xml. I get these errors: [ERR] avformat.c:411 Could not open audio codec: Experimental feature [ERR] conference_record.c:241 Error Opening File [{channels=2,samplerate=8000,vw=640,vh=480,fps=15.00}/var/lib/freeswitch/recordings/$1-10.61.82.56_2015-11-05-14-45-00.mp4] Do I need to compile FreeSWITCH from latest source to get this to work?