Here are the example options i using: -audio-preload 2.0 -oac copy -ovc lavc -lavcopts vcodec=mpeg2video :autoaspect:keyint=300:vbitrate=1200:naq:lumi_mask=0.3:dark_mask=0.3 :p_mask=0.1:dc=11:trell:mv0:mbd=2:qprd:cbp:predia=2:dia=2:preme=2 :vb_strategy=1:vmax_b_frames=0 -of mpeg -o "%userprofile%\desktop\%~n1.mpg" if i set vmax_b_frames equal or more than 1 mencoder will report this repeatly: [mpeg2video @ 00D8CC98]Error, Invalid timestamp=0, last=0V:0.000 [0:0] Muxer frame buffer cannot allocate memory! ... and end up with a 0kb of file. im sure the cvs version of libmpcodecs(ve_lavc.c?) have problem, because the older version of libmpcodecs works fine with b-frames encoding.