[Ubuntu-BR] Mencoder erro ao converter para mjpeg

[Paulo Correia]

Amigos estou usando a seguinte linha de comando:

mencoder convertVideo.avi -o video.mjpeg -ovc lavc -lavcopts 
vcodec=mjpeg -nosound

Obtenho a saída:

MEncoder 1.1-4.7 (C) 2000-2012 MPlayer Team
success: format: 0  data: 0x0 - 0x866b32a
libavformat version 54.6.100 (internal)
AVI file format detected.
[aviheader] Video stream found, -vid 0
VIDEO:  [WMV2]  720x480  24bpp  29.794 fps  1934.8 kbps (236.2 kbyte/s)
[V] filefmt:3  fourcc:0x32564D57  size:720x480  fps:29.794 ftime:=0.0336
libavcodec version 54.23.100 (internal)
Opening video filter: [expand osd=1]
Expand: -1 x -1, -1 ; -1, osd: 1, aspect: 0.000000, round: 1
==========================================================================
Opening video decoder: [ffmpeg] FFmpeg's libavcodec codec family
Selected video codec: [ffwmv2] vfm: ffmpeg (FFmpeg WMV2/WMV8)
==========================================================================
Movie-Aspect is undefined - no prescaling applied.
videocodec: libavcodec (720x480 fourcc=47504a4d [MJPG])
[mjpeg @ 0xe757c0]Specified pix_fmt is not supported
Could not open codec.
FATAL: Cannot initialize video driver.
Movie-Aspect is undefined - no prescaling applied.
videocodec: libavcodec (720x480 fourcc=47504a4d [MJPG])
[mjpeg @ 0xe757c0]Specified pix_fmt is not supported
Could not open codec.
FATAL: Cannot initialize video driver.

Já pesquisei e nada achei, alguém tem uma ideia do que falta ?