[root@localhost recordings]# mencoder 3191_20070224103000.mpg -nosound -ovc lavc -lavcopts vcodec=flv -of lavf -lavfopts format=flv -o test2.flv
MEncoder dev-SVN-r22356-4.1.1 (C) 2000-2006 MPlayer Team
CPU: AMD Athlon(tm) 64 Processor 3000+ (Family: 15, Model: 12, Stepping: 0)
CPUflags: Type: 15 MMX: 1 MMX2: 1 3DNow: 1 3DNow2: 1 SSE: 1 SSE2: 1
Compiled for x86 CPU with extensions: MMX MMX2 3DNow 3DNowEx SSE SSE2

success: format: 0  data: 0x0 - 0x86eaa038
TS file format detected.
VIDEO MPEG2(pid=2176) NO AUDIO!  NO SUBS (yet)!  PROGRAM N. 1
VIDEO:  MPEG2  1920x1080  (aspect 3)  29.970 fps  25000.0 kbps (3125.0 kbyte/s)
[V] filefmt:29  fourcc:0x10000002  size:1920x1080  fps:29.97  ftime:=0.0334
** MUXER_LAVF *****************************************************************
If you wish to use libavformat muxing, you must ensure that your video stream
does not contain B frames (out of order decoding) and specify:
    -lavfopts i_certify_that_my_video_stream_does_not_use_b_frames
on the command line.
REMEMBER: MEncoder's libavformat muxing is presently broken and will generate
INCORRECT files in the presence of B frames. Moreover, due to bugs MPlayer
will play these INCORRECT files as if nothing were wrong!
*******************************************************************************
Cannot initialize muxer.
Exiting...