[MEncoder-users] resizing a SWF, vp6

[adam k]

i'm trying to resize a SWF that's encoded in On2's vp6 format, with the 
following line:

/usr/local/bin/mencoder airplane1_cinh.swf -nosound  -ovc lavc -of lavf 
-lavfopts i_certify_that_my_video_stream_does_not_use_b_frames -vf 
scale=100:75 -o airplaneResized4.swf

but i get the error [NULL @ 0xbdd310]SWF only supports VP6, FLV1 and MJPEG

what am i doing wrong? i don't understand the error message, i've 
searched it and haven't found any helpful info.   i've pasted the full 
log below. 

thank you for your time.

----------------

MEncoder 1.0rc1-4.1.1 (C) 2000-2006 MPlayer Team
CPU: AMD Opteron(tm) Processor 254 (Family: 15, Model: 37, Stepping: 1)
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 - 0x172af2
libavformat file format detected.
Seek failed
VIDEO:  [VP6F]  320x240  0bpp  30.000 fps    0.0 kbps ( 0.0 kbyte/s)
[V] filefmt:35  fourcc:0x46365056  size:320x240  fps:30.00  ftime:=0.0333
** MUXER_LAVF 
*****************************************************************
You have certified that your video stream does not contain B frames.
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!
*******************************************************************************
OK, exit
Opening video filter: [expand osd=1]
Expand: -1 x -1, -1 ; -1, osd: 1, aspect: 0.000000, round: 1
Opening video filter: [scale w=100 h=75]
==========================================================================
Opening video decoder: [ffmpeg] FFmpeg's libavcodec codec family
Selected video codec: [ffvp6f] vfm: ffmpeg (FFmpeg VP6 Flash decoder)
==========================================================================
VDec: vo config request - 320 x 240 (preferred colorspace: Planar YV12)
VDec: using Planar YV12 as output csp (no 0)
Movie-Aspect is undefined - no prescaling applied.
SwScaler: reducing / aligning filtersize 14 -> 16
SwScaler: reducing / aligning filtersize 14 -> 16
SwScaler: reducing / aligning filtersize 14 -> 13
SwScaler: reducing / aligning filtersize 14 -> 13

SwScaler: BICUBIC scaler, from yuv420p to yuv420p using MMX2
SwScaler: using n-tap MMX scaler for horizontal luminance scaling
SwScaler: using n-tap MMX scaler for horizontal chrominance scaling
SwScaler: using n-tap MMX scaler for vertical scaling (YV12 like)
SwScaler: 320x240 -> 100x76
videocodec: libavcodec (100x76 fourcc=34504d46 [FMP4])
VIDEO CODEC ID: 13
Writing header...
[NULL @ 0xbdd310]SWF only supports VP6, FLV1 and MJPEG
Floating point exception