mencoder mf:// *.jpg -mf w=320:h=240:fps=9.6:type=jpg -ovc lavc \ -lavcopts vcodec=mpeg4:mbd=2:trell -oac copy -o foo.avi
MEncoder 2:0.99+1.0pre8-0ubuntu8 (C) 2000-2006 MPlayer Team
CPU:         Intel(R) Pentium(R) M processor 1500MHz (Family: 6, Model: 9, Stepping: 5)
CPUflags: Type: 6 MMX: 1 MMX2: 1 3DNow: 0 3DNow2: 0 SSE: 1 SSE2: 1
Compiled with runtime CPU detection.
success: format: 16  data: 0x0 - 0x0
[mf] search expr: *
[mf] number of files: 296 (1184)
[demux_mf] file type was not set! trying 'type=avi'...
[demux_mf] unknown input file type.
============ Sorry, this file format is not recognized/supported =============
=== If this file is an AVI, ASF or MPEG stream, please contact the author! ===
Cannot open demuxer.

Exiting...