ISSUE: ffmpeg compiled against iOS 10 SDK (XCode 8) will produce crash while accessing any RTSP source if it is running on iOS 9.x with the following error: `dyld: Symbol not found: _clock_gettime` The problem is that iOS 10 has clock_gettime function, but iOS 9 does not have. FIX: Right after configure put this line `sed -i -- 's/HAVE_CLOCK_GETTIME 1/HAVE_CLOCK_GETTIME 0/g' config.h`