Comment 2 for bug 1241772

I can confirm this. It affects anything that uses libx264, not just VLC but also avconv (the command line tool) and any program that encodes video with libavcodec (i.e. most video editors and screencasting software).

The backtrace in avconv is mostly the same:
#0 __memcmp_ssse3 () at ../sysdeps/x86_64/multiarch/memcmp-ssse3.S:1684
#1 0x00007ffff3012d9e in x264_cqm_init () from /usr/lib/x86_64-linux-gnu/libx264.so.123
#2 0x00007ffff307d374 in x264_encoder_open_123 () from /usr/lib/x86_64-linux-gnu/libx264.so.123
#3 0x00007ffff693736c in ?? () from /usr/lib/x86_64-linux-gnu/libavcodec.so.53
#4 0x00007ffff6cc25f5 in avcodec_open2 () from /usr/lib/x86_64-linux-gnu/libavcodec.so.53
#5 0x00000000004051aa in ?? ()
#6 0x00007ffff59aede5 in __libc_start_main (main=0x404c10, argc=12, ubp_av=0x7fffffffe008, init=<optimized out>,
    fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7fffffffdff8) at libc-start.c:260
#7 0x0000000000407983 in ?? ()