ffmpeg -i  /mnt/hgfs/D/stream/title4.vob   -an -vn -sbsf  mov2textsub -c:s copy  -f rawvideo  sub.txt
ffmpeg version N-31002-ga8e6d4d, Copyright (c) 2000-2011 the FFmpeg developers
  built on Nov 22 2011 19:45:04 with gcc 4.4.3
  configuration: --enable-gpl --enable-libfaac --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libtheora --enable-libvorbis --enable-libx264 --enable-libxvid --enable-nonfree --enable-postproc --enable-version3 --enable-x11grab --enable-libaacplus
  libavutil    51. 26. 0 / 51. 26. 0
  libavcodec   53. 36. 0 / 53. 36. 0
  libavformat  53. 21. 0 / 53. 21. 0
  libavdevice  53.  4. 0 / 53.  4. 0
  libavfilter   2. 49. 0 /  2. 49. 0
  libswscale    2.  1. 0 /  2.  1. 0
  libpostproc  51.  2. 0 / 51.  2. 0
[mpeg @ 0xa262a80] max_analyze_duration 5000000 reached at 5024000
Input #0, mpeg, from '/mnt/hgfs/D/stream/title4.vob':
  Duration: 00:11:47.00, start: 0.053622, bitrate: 6506 kb/s
    Stream #0:0[0x1e0]: Video: mpeg2video (Main), yuv420p, 720x576 [SAR 64:45 DAR 16:9], 9800 kb/s, 25 fps, 25 tbr, 90k tbn, 50 tbc
    Stream #0:1[0x82]: Audio: ac3, 48000 Hz, stereo, s16, 192 kb/s
    Stream #0:2[0x21]: Subtitle: dvd_subtitle
    Stream #0:3[0x20]: Subtitle: dvd_subtitle
Unrecognized option 'sbsf'
Failed to set value 'mov2textsub' for option 'sbsf'