(gdb) bt
#0  0x0018f402 in __kernel_vsyscall ()
#1  0x0027d159 in raise () from /lib/libc.so.6
#2  0x0027e6e3 in abort () from /lib/libc.so.6
#3  0x00276abd in __assert_fail () from /lib/libc.so.6
#4  0x085a6173 in x264_ratecontrol_new ()
#5  0x08558ec1 in x264_encoder_open ()
#6  0x080aa2de in config ()