Description:
I'm running a server for encoding videos - dmesg and /var/log/messages have filled up with ffmpeg segfault at libx264.so.124.
If I rerun the same encode it may complete as expected or segfault again. I would say from every 4-5 encodes, 1 fails.

Additional info:
* package version(s)
ffmpeg/mencoder/x264 etc - all packages are latest versions ffmpeg 1:1.0-1, x264 20120705-1, mencoder 35014-1
* config and/or log files etc.
Oct 9 12:27:57 ENC02 kernel: [ 5293.209346] mencoder[23135] general protection ip:7fb0c1ebb463 sp:7fb0b5040c58 error:0 in libx264.so.124[7fb0c1e09000+d0000]
Oct 9 12:32:35 ENC02 kernel: [ 5570.514138] mencoder[23437]: segfault at 74a6b554 ip 00007fd03b3c3c73 sp 00007fd0325a2b10 error 4 in libx264.so.124[7fd03b363000+d0000]
Oct 9 12:32:59 ENC02 kernel: [ 5594.758290] ffmpeg[24783]: segfault at ffff ip 00007fe838efc0c0 sp 00007fe82d3267f0 error 4 in libx264.so.124 (deleted)[7fe838ebc000+d0000]
Oct 9 12:36:54 ENC02 kernel: [ 5830.063832] ffmpeg[25937]: segfault at 0 ip 00007f0850e83865 sp 00007f0847639f38 error 4 in libx264.so.124[7f0850e4b000+d0000]
Oct 9 12:40:44 ENC02 kernel: [ 6059.446817] ffmpeg[27355]: segfault at 7 ip 00007ffb34ea4865 sp 00007ffb2ae59f38 error 4 in libx264.so.124[7ffb34e6c000+d0000]
Oct 9 12:52:22 ENC02 kernel: [ 6757.441815] ffmpeg[30317]: segfault at 7 ip 00007fde048bf865 sp 00007fddfc878f38 error 4 in libx264.so.124[7fde04887000+d0000]
Oct 9 12:55:17 ENC02 kernel: [ 6932.515081] ffmpeg[30588]: segfault at ffff ip 00007f3129af30c0 sp 00007f311df1d7f0 error 4 in libx264.so.124[7f3129ab3000+d0000]
Oct 9 12:58:02 ENC02 kernel: [ 7096.767650] ffmpeg[31307]: segfault at ffff ip 00007f9ccf6370c0 sp 00007f9cc3a617f0 error 4 in libx264.so.124[7f9ccf5f7000+d0000]
Oct 9 13:00:16 ENC02 kernel: [ 7230.620951] ffmpeg[31511]: segfault at ffff ip 00007fea92afa0c0 sp 00007fea86f247f0 error 4 in libx264.so.124[7fea92aba000+d0000]
Oct 9 13:00:51 ENC02 kernel: [ 7265.859895] ffmpeg[31477]: segfault at ffff ip 00007fceda0be0ec sp 00007fcece4e87f0 error 4 in libx264.so.124[7fceda07e000+d0000]
Oct 9 13:01:14 ENC02 kernel: [ 7289.298130] ffmpeg[31994]: segfault at 1 ip 00007f7992402865 sp 00007f7989bbaf38 error 4 in libx264.so.124[7f79923ca000+d0000]
Oct 9 13:03:12 ENC02 kernel: [ 7406.801556] ffmpeg[32087]: segfault at 20 ip 00007f1876fe80ec sp 00007f186b4127f0 error 4 in libx264.so.124[7f1876fa8000+d0000]
Oct 9 13:05:06 ENC02 kernel: [ 7521.042635] ffmpeg[32030]: segfault at ffff ip 00007f5a00c4e0c0 sp 00007f59f50787f0 error 4 in libx264.so.124[7f5a00c0e000+d0000]
Oct 9 13:05:37 ENC02 kernel: [ 7551.979068] ffmpeg[32403]: segfault at ffff ip 00007f672d31c0c0 sp 00007f67217467f0 error 4 in libx264.so.124[7f672d2dc000+d0000]
Oct 9 13:10:10 ENC02 kernel: [ 7824.994550] ffmpeg[32748]: segfault at ffff ip 00007f52725850c0 sp 00007f52669af7f0 error 4 in libx264.so.124[7f5272545000+d0000]
Oct 9 13:11:47 ENC02 kernel: [ 7921.795615] ffmpeg[33210]: segfault at ffff ip 00007f532c76b0c0 sp 00007f5320b957f0 error 4 in libx264.so.124[7f532c72b000+d0000]
Oct 9 13:15:46 ENC02 kernel: [ 8160.287198] ffmpeg[33268]: segfault at ffff ip 00007ff09b42a0c0 sp 00007ff08f8547f0 error 4 in libx264.so.124[7ff09b3ea000+d0000]
Oct 9 13:24:03 ENC02 kernel: [ 8656.737819] ffmpeg[34329]: segfault at ffff ip 00007f13014a90c0 sp 00007f12f58d37f0 error 4 in libx264.so.124[7f1301469000+d0000]
Oct 9 13:30:12 ENC02 kernel: [ 9026.207639] ffmpeg[35000]: segfault at ffff ip 00007fe92f5780c0 sp 00007fe9239a27f0 error 4 in libx264.so.124[7fe92f538000+d0000]
Oct 9 13:30:57 ENC02 kernel: [ 9070.930276] ffmpeg[34423]: segfault at 8 ip 00007fc780c2a0ec sp 00007fc7750547f0 error 4 in libx264.so.124[7fc780bea000+d0000]
Oct 9 13:40:00 ENC02 kernel: [ 9613.932335] ffmpeg[36114]: segfault at ffff ip 00007f9d134cd0c0 sp 00007f9d078f77f0 error 4 in libx264.so.124[7f9d1348d000+d0000]
Oct 9 13:48:07 ENC02 kernel: [10099.973886] ffmpeg[37111]: segfault at ffff ip 00007fac4d8840c0 sp 00007fac41cae7f0 error 4 in libx264.so.124[7fac4d844000+d0000]
Oct 9 13:48:30 ENC02 kernel: [10123.549814] ffmpeg[36145]: segfault at 10 ip 00007f4ed19340ec sp 00007f4ec5d5e7f0 error 4 in libx264.so.124[7f4ed18f4000+d0000]



Steps to reproduce:
run:
ffmpeg -deinterlace -y -i "/tmp/video.mp4" -force_key_frames 0 -r 29.970 -threads 12 -aspect 4:3 -vf "scale=480:352 [in]; movie=/tmp/logo.png [logo]; [in][logo] overlay=W-w-5:H-h-5 [out]" -vcodec libx264 -vpre ultrafast -b:v 10000k -acodec libmp3lame -ab 320k -ac 2 -async 44100 /tmp/temp.avi

1 out of 5 times or so that gives a segfault

This server has been running memtest for 2 days without error, mprime for 1 day without error.