It seems a commit made by Michael to libavcodec/mpegvideo.c on 2004/10/15 (r1.441) is the cause of b-frame encoding no longer working properly. ---------------------------- revision 1.441 date: 2004/10/14 12:24:16; author: michael; state: Exp; lines: +11 -11 fix forcing of individual frame types ---------------------------- Now, encoding with b-frames will crash early in the second pass. See the thread on advusers for report, test case, etc. http://mplayerhq.hu/pipermail/mplayer-advusers/2005-May/001134.html Message-Id: <200505101320.23465.hans_meine@gmx.net>