Encoding (finishes now, there was indeed a png with diffrent size):
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$ mencoder mf://*.png -ovc xvid -xvidencopts fixed_quant=2 -of avi -o lightturn.avi
MEncoder 1.0rc1-4.1.1 (C) 2000-2006 MPlayer Team
CPU: AMD Athlon(tm) XP 2600+ (Family: 6, Model: 10, Stepping: 0)
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

success: format: 16  data: 0x0 - 0x0
MF file format detected.
[mf] search expr: *.png
[mf] number of files: 100 (400)
[demux_mf] file type was not set! trying 'type=png'...
VIDEO:  [MPNG]  0x0  24bpp  25.000 fps    0.0 kbps ( 0.0 kbyte/s)
[V] filefmt:16  fourcc:0x474E504D  size:0x0  fps:25.00  ftime:=0.0400
xvid: using library version 1.1.0 (build xvid-1.1.0)
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: [ffpng] vfm: ffmpeg (FFmpeg PNG decoder)
==========================================================================
VDec: vo config request - 480 x 352 (preferred colorspace: RGB 24-bit)
Could not find matching colorspace - retrying with -vf scale...
Opening video filter: [scale]
VDec: using RGB 24-bit as output csp (no 5)
Movie-Aspect is undefined - no prescaling applied.
SwScaler: reducing / aligning filtersize 1 -> 4
SwScaler: reducing / aligning filtersize 1 -> 4
SwScaler: reducing / aligning filtersize 1 -> 1
SwScaler: reducing / aligning filtersize 9 -> 8

SwScaler: BICUBIC scaler, from rgb24 to yuv420p using MMX2
SwScaler: using 4-tap MMX scaler for horizontal luminance scaling
SwScaler: using 4-tap MMX scaler for horizontal chrominance scaling
SwScaler: using 1-tap MMX "scaler" for vertical scaling (YV12 like)
SwScaler: 480x352 -> 480x352
videocodec: XviD (480x352 fourcc=44495658 [XVID])
xvid: par=0/0 (vga11), displayed=480x352, sampled=480x352
xvid: Fixed Quant Rate Control -- quantizer=2/1=2.00
New_Face failed. Maybe the font path is wrong.
Please supply the text font file (~/.mplayer/subfont.ttf).
subtitle font: load_sub_face failed.
Writing header...
ODML: vprp aspect is 16384:12014.
Writing header...
ODML: vprp aspect is 16384:12014.
Pos:   3.9s    100f (100%) 26.54fps Trem:   0min   0mb  A-V:0.000 [1084:0]
Flushing video frames
Writing index...
Writing header...
ODML: vprp aspect is 16384:12014.

Video stream: 1077.762 kbit/s  (134720 B/s)  size: 538881 bytes  4.000 secs  100 frames
----------------------------------------------------------------------------------------



However the mplayer-window still does not show the movie in 480x352, but scales the window a little larger.
The console-output of mplayer is:

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$ mplayer lightturn.avi -loop 0                 
MPlayer 1.0rc1-4.1.1 (C) 2000-2006 MPlayer Team
CPU: AMD Athlon(tm) XP 2600+ (Family: 6, Model: 10, Stepping: 0)
CPUflags:  MMX: 1 MMX2: 1 3DNow: 1 3DNow2: 1 SSE: 1 SSE2: 0
Compiled for x86 CPU with extensions: MMX MMX2 3DNow 3DNowEx SSE
Can't open joystick device /dev/input/js0: No such file or directory
Can't init input joystick

Playing lightturn.avi.
AVI file format detected.
AVI_NI: No audio stream found -> no sound.
AVI: No audio stream found -> no sound.
VIDEO:  [XVID]  480x352  12bpp  25.000 fps  1077.8 kbps (131.6 kbyte/s)
Clip info:
 Software: MEncoder 1.0rc1-4.1.1
==========================================================================
Opening video decoder: [ffmpeg] FFmpeg's libavcodec codec family
Selected video codec: [ffodivx] vfm: ffmpeg (FFmpeg MPEG-4)
==========================================================================
Audio: no sound
Starting playback...
VDec: vo config request - 480 x 352 (preferred colorspace: Planar YV12)
VDec: using Planar YV12 as output csp (no 0)
Movie-Aspect is 1.36:1 - prescaling to correct movie aspect.
VO: [xv] 480x352 => 480x352 Planar YV12 
V:   0.3   8/  8 ??% ??% ??,?% 0 0 
Exiting... (Quit)
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