root@spitz:~# mencoder "astrochem1.avi" -ovc lavc -lavcopts vcodec=mpeg4:vbitrate=300:vpass=1 -lameopts cbr:br=64:mode=3 -vf scale=320:240 -oac mp3lame -o astrochem1.mpg
MEncoder 1.0pre8-3.4.4 (C) 2000-2006 MPlayer Team
CPU: ARM

WARNING: OUTPUT FILE FORMAT IS _AVI_. See -of help.
success: format: 0  data: 0x0 - 0x342d000
REAL file format detected.
Stream description: video/x-pn-multirate-realvideo logical stream
Stream mimetype: video/x-pn-realvideo
Stream description: audio/x-pn-multirate-realaudio logical stream
Stream mimetype: audio/x-pn-realaudio
VIDEO:  [RV40]  320x240  24bpp  15.000 fps    0.0 kbps ( 0.0 kbyte/s)
[V] filefmt:11  fourcc:0x30345652  size:320x240  fps:15.00  ftime:=0.0667
==========================================================================
Opening audio decoder: [ffmpeg] FFmpeg/libavcodec audio decoders
AUDIO: 44100 Hz, 2 ch, s16le, 96.5 kbit/6.84% (ratio: 12058->176400)
Selected audio codec: [ffcook] afm: ffmpeg (FFmpeg COOK audio decoder)
==========================================================================
Opening video filter: [expand osd=1]
Expand: -1 x -1, -1 ; -1, osd: 1, aspect: 0.000000, round: 1
Opening video filter: [scale w=320 h=240]
==========================================================================
Requested video codec family [rv3040] (vfm=realvid) not available.
Enable it at compilation.
Requested video codec family [rv40] (vfm=realvid) not available.
Enable it at compilation.
Requested video codec family [rv40win] (vfm=realvid) not available.
Enable it at compilation.
Requested video codec family [rv40mac] (vfm=realvid) not available.
Enable it at compilation.
Cannot find codec matching selected -vo and video format 0x30345652.
Read DOCS/HTML/en/codecs.html!
==========================================================================

Exiting...