Following the report of a user (http://lists.mplayerhq.hu/pipermail/mencoder-users/2007-December/007588.html) I have found the following bug: if i create a file containing mpeg video copied from an mpeg stream like: mencoder -of mpeg -mpegopts format=dvd -ovc copy -o test.mpg dvd://1 -chapter 2 -frames 1000 -oac copy or even mencoder -ovc copy -o test.avi dvd://1 -chapter 2 -frames 1000 -oac copy then the first 1/2 frames are corrupted. The bug was introduced with r22112: (demux_mpg_probe() seek to the initial position before returning - patch by reimar) --- trunk/libmpdemux/demux_mpg.c 2007/02/03 11:32:43 22106 +++ trunk/libmpdemux/demux_mpg.c 2007/02/03 14:09:47 22112 @@ -673,6 +673,8 @@ mp_msg(MSGT_DEMUXER,MSGL_V,MSGTR_NotSystemStream); } } + //FIXME this shouldn't be necessary + stream_seek(demuxer->stream,tmppos); return file_format; } Ciao Giacomo