$ mencoder mf://@allpics.txt -mf w=448:h=336:fps=29:type=jpg -ovc lavc -lavcopts vcodec=mpeg4:mbd=2:trell -oac copy -o all_vids.avi


MEncoder 1.0pre7try2-3.3.6 (C) 2000-2005 MPlayer Team
CPU: Advanced Micro Devices Athlon MP/XP Thoroughbred (Family: 6, Stepping: 1)
Detected cache-line size is 64 bytes
CPUflags: Type: 6 MMX: 1 MMX2: 1 3DNow: 1 3DNow2: 1 SSE: 1 SSE2: 0
Compiled for x86 CPU with extensions: MMX MMX2 3DNow 3DNowEx SSE

File not found: 'frameno.avi'
Failed to open frameno.avi
success: format: 16  data: 0x0 - 0x0
[demuxer] mf support.
[mf] search expr: @allpics.txt*
============ 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...
$