Would it be possible to get the correct version of libx264 from git and compile it along with ffmpeg so errors like this don't show up, depending on what version is in the distro being used?
libx264.c: In function 'X264_init':
libx264.c:165: error: 'x264_param_t' has no member named 'b_bframe_adaptive'
libx264.c:230: error: 'struct <anonymous>' has no member named 'b_bidir_me'
libx264.c:231: error: 'struct <anonymous>' has no member named 'b_bframe_rdo'
libx264.c:256: error: 'struct <anonymous>' has no member named 'psz_rc_eq'
If the next version of mplayer-vdpau fetched and compiled a compatible version of libx264 it would make things easier and probably save some posts to this list.