snow: fail with decode of 2x2 resolution

[ami_stuff]

i'm not sure if this is a bug in encoder (missing check for minimal supported resolution) or in decoder

C:\>ffmpeg -i 2.avi -vcodec snow -pix_fmt yuv420p -strict -2 out.avi
ffmpeg version N-45867-g3318d6b Copyright (c) 2000-2012 the FFmpeg developers
  built on Oct 23 2012 02:39:33 with gcc 4.5.0 (GCC) 20100414 (Fedora MinGW 4.5.
0-1.fc14)
  configuration: --prefix=/var/www/users/research/ffmpeg/snapshots/build --arch=
x86 --target-os=mingw32 --cross-prefix=i686-pc-mingw32- --cc='ccache i686-pc-min
gw32-gcc' --enable-w32threads --enable-memalign-hack --enable-runtime-cpudetect
--enable-cross-compile --enable-static --disable-shared --extra-libs='-lws2_32 -
lwinmm -lpthread' --extra-cflags='--static -I/var/www/users/research/ffmpeg/snap
shots/build/include' --extra-ldflags='-static -L/var/www/users/research/ffmpeg/s
napshots/build/lib' --enable-bzlib --enable-zlib --enable-gpl --enable-version3
--enable-nonfree --enable-libx264 --enable-libspeex --enable-libtheora --enable-
libvorbis --enable-libfaac --enable-libxvid --enable-libopencore-amrnb --enable-
libopencore-amrwb --enable-libmp3lame --enable-libvpx --disable-decoder=libvpx
  libavutil      51. 77.100 / 51. 77.100
  libavcodec     54. 68.100 / 54. 68.100
  libavformat    54. 33.100 / 54. 33.100
  libavdevice    54.  3.100 / 54.  3.100
  libavfilter     3. 20.104 /  3. 20.104
  libswscale      2.  1.101 /  2.  1.101
  libswresample   0. 16.100 /  0. 16.100
  libpostproc    52.  1.100 / 52.  1.100
Input #0, avi, from '2.avi':
  Duration: 00:00:00.10, start: 0.000000, bitrate: 664 kb/s
    Stream #0:0: Video: cinepak (cvid / 0x64697663), yuv420p, 2x2, 10 tbr, 10 tb
n, 10 tbc
Output #0, avi, to 'out.avi':
  Metadata:
    ISFT            : Lavf54.33.100
    Stream #0:0: Video: snow (SNOW / 0x574F4E53), yuv420p, 2x2, q=2-31, 200 kb/s
, 10 tbn, 10 tbc
Stream mapping:
  Stream #0:0 -> #0:0 (cinepak -> snow)
Press [q] to stop, [?] for help
frame=    1 fps=0.0 q=0.0 Lsize=       6kB time=00:00:00.10 bitrate= 457.0kbits/
s
video:0kB audio:0kB subtitle:0 global headers:0kB muxing overhead 95100.000000%

C:\>ffmpeg -i out.avi out2.avi
ffmpeg version N-45867-g3318d6b Copyright (c) 2000-2012 the FFmpeg developers
  built on Oct 23 2012 02:39:33 with gcc 4.5.0 (GCC) 20100414 (Fedora MinGW 4.5.
0-1.fc14)
  configuration: --prefix=/var/www/users/research/ffmpeg/snapshots/build --arch=
x86 --target-os=mingw32 --cross-prefix=i686-pc-mingw32- --cc='ccache i686-pc-min
gw32-gcc' --enable-w32threads --enable-memalign-hack --enable-runtime-cpudetect
--enable-cross-compile --enable-static --disable-shared --extra-libs='-lws2_32 -
lwinmm -lpthread' --extra-cflags='--static -I/var/www/users/research/ffmpeg/snap
shots/build/include' --extra-ldflags='-static -L/var/www/users/research/ffmpeg/s
napshots/build/lib' --enable-bzlib --enable-zlib --enable-gpl --enable-version3
--enable-nonfree --enable-libx264 --enable-libspeex --enable-libtheora --enable-
libvorbis --enable-libfaac --enable-libxvid --enable-libopencore-amrnb --enable-
libopencore-amrwb --enable-libmp3lame --enable-libvpx --disable-decoder=libvpx
  libavutil      51. 77.100 / 51. 77.100
  libavcodec     54. 68.100 / 54. 68.100
  libavformat    54. 33.100 / 54. 33.100
  libavdevice    54.  3.100 / 54.  3.100
  libavfilter     3. 20.104 /  3. 20.104
  libswscale      2.  1.101 /  2.  1.101
  libswresample   0. 16.100 /  0. 16.100
  libpostproc    52.  1.100 / 52.  1.100
[snow @ 0x1edc700] Error s->spatial_decomposition_count is 0
[avi @ 0x1edbe20] decoding for stream 0 failed
[avi @ 0x1edbe20] Could not find codec parameters for stream 0 (Video: snow (SNO
W / 0x574F4E53), 2x2): unspecified pixel format
Consider increasing the value for the 'analyzeduration' and 'probesize' options
out.avi: could not find codec parameters