ffmpeg subtitles codec error

$ ffmpeg -i input.m4v -an -vn -scodec ass out.ass

ffmpeg version 0.10 Copyright (c) 2000-2012 the FFmpeg developers
  built on Feb 26 2012 15:53:55 with gcc 4.5.0 20100604 [gcc-4_5-branch revision                                                                                                  160292]
  configuration: --prefix=/home/mneumann/local --enable-libmp3lame --enable-libx                                                                                                 264 --enable-gpl --extra-ldflags=-L/home/mneumann/local/lib --disable-devices
  libavutil      51. 34.101 / 51. 34.101
  libavcodec     53. 60.100 / 53. 60.100
  libavformat    53. 31.100 / 53. 31.100
  libavdevice    53.  4.100 / 53.  4.100
  libavfilter     2. 60.100 /  2. 60.100
  libswscale      2.  1.100 /  2.  1.100
  libswresample   0.  6.100 /  0.  6.100
  libpostproc    52.  0.100 / 52.  0.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'input.m4v':
  Metadata:
    major_brand     : M4V
    minor_version   : 1
    compatible_brands: M4V M4A mp42isom
    creation_time   : 2011-01-28 15:29:29
    title           : This is the reception!-LU SD
    episode_id      : 000
    hd_video        : 0
    media_type      : 0
    gapless_playback: 0
  Duration: 00:01:03.08, start: 0.000000, bitrate: 1529 kb/s
    Stream #0:0(eng): Video: h264 (Constrained Baseline) (avc1 / 0x31637661), yu                                                                                                 v420p, 640x360, 1430 kb/s, 25 fps, 25 tbr, 2500 tbn, 5k tbc
    Metadata:
      creation_time   : 2011-01-28 15:29:29
      handler_name    : Apple Video Media Handler
    Stream #0:1(eng): Audio: aac (mp4a / 0x6134706D), 44100 Hz, stereo, s16, 91                                                                                                  kb/s
    Metadata:
      creation_time   : 2011-01-28 15:29:29
      handler_name    : Apple Sound Media Handler
    Stream #0:2(eng): Subtitle: mov_text (tx3g / 0x67337874)
    Metadata:
      creation_time   : 2011-02-04 11:52:01
      handler_name    :
Output #0, ass, to 'out.ass':
  Metadata:
    major_brand     : M4V
    minor_version   : 1
    compatible_brands: M4V M4A mp42isom
    creation_time   : 2011-01-28 15:29:29
    title           : This is the reception!-LU SD
    episode_id      : 000
    hd_video        : 0
    media_type      : 0
    gapless_playback: 0
    Stream #0:0(eng): Subtitle: ssa
    Metadata:
      creation_time   : 2011-02-04 11:52:01
      handler_name    :
Stream mapping:
  Stream #0:2 -> #0:0 (? -> ass)
Decoder (codec mov_text) not found for input stream #0:2