snow enc: hang with -s 32x32

[ami_stuff]

​http://ffmpeg.org/trac/ffmpeg/raw-attachment/ticket/1082/h261.avi

(gdb) r -i h261.avi -vcodec snow -strict -2 -s 32x32 out.avi
Starting program: d:\mingw\msys\1.0\ffmpeg\ffmpeg_g.exe -i h261.avi -vcodec snow
 -strict -2 -s 32x32 out.avi
[New Thread 3956.0xd40]
ffmpeg version 0.9.1.git Copyright (c) 2000-2012 the FFmpeg developers
  built on Mar 10 2012 16:15:15 with gcc 4.6.1
  configuration: --disable-yasm --disable-ffprobe
  libavutil      51. 42.100 / 51. 42.100
  libavcodec     54. 10.100 / 54. 10.100
  libavformat    54.  2.100 / 54.  2.100
  libavdevice    53.  4.100 / 53.  4.100
  libavfilter     2. 63.100 /  2. 63.100
  libswscale      2.  1.100 /  2.  1.100
  libswresample   0.  7.100 /  0.  7.100
Input #0, avi, from 'h261.avi':
  Metadata:
    encoder         : Lavf54.2.100
  Duration: 00:00:00.04, start: 0.000000, bitrate: 1863 kb/s
    Stream #0:0: Video: h261 (H261 / 0x31363248), yuv420p, 352x288, 25 tbr, 25 t
bn, 25 tbc
File 'out.avi' already exists. Overwrite ? [y/N] y
w:352 h:288 pixfmt:yuv420p tb:1/1000000 sar:0/1 sws_param:
[scale @ 038722c0] w:352 h:288 fmt:yuv420p -> w:32 h:32 fmt:yuv420p flags:0x4
Output #0, avi, to 'out.avi':
  Metadata:
    ISFT            : Lavf54.2.100
    Stream #0:0: Video: snow (SNOW / 0x574F4E53), yuv420p, 32x32, q=2-31, 200 kb
/s, 25 tbn, 25 tbc
Stream mapping:
  Stream #0:0 -> #0:0 (h261 -> snow)
Press [q] to stop, [?] for help
[h261 @ 03dd0920] warning: first frame is no keyframe

[llogan]

Hangs for me (killed at 76 minutes) at 63x63, but not 64x64. I'm unsure if this is a regression.