Извлечение субтитров из видеофайла не работает

Я пытаюсь извлечь субтитры из файла MKV, но безуспешно.

Моя команда:

ffmpeg -i movie.mkv -map 0:s:0 subs.srt

Я получил:

Unable to find a suitable output format for 'subs.srt'

Я использую CentOS 6.5

Полный вывод:

$ ffmpeg -i movie.mkv -map 0:s:0 subs.srt
FFmpeg version 0.6.5, Copyright (c) 2000-2010 the FFmpeg developers
  built on Jan 29 2012 17:52:15 with gcc 4.4.5 20110214 (Red Hat 4.4.5-6)
  configuration: --prefix=/usr --libdir=/usr/lib64 --shlibdir=/usr/lib64 --mandir=/usr/share/man --incdir=/usr/include --disable-avisynth --extra-cflags='-O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector --param=ssp-buffer-size=4 -m64 -mtune=generic -fPIC' --enable-avfilter --enable-avfilter-lavf --enable-libdc1394 --enable-libdirac --enable-libfaac --enable-libfaad --enable-libfaadbin --enable-libgsm --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-librtmp --enable-libschroedinger --enable-libspeex --enable-libtheora --enable-libx264 --enable-gpl --enable-nonfree --enable-postproc --enable-pthreads --enable-shared --enable-swscale --enable-vdpau --enable-version3 --enable-x11grab
  libavutil     50.15. 1 / 50.15. 1
  libavcodec    52.72. 2 / 52.72. 2
  libavformat   52.64. 2 / 52.64. 2
  libavdevice   52. 2. 0 / 52. 2. 0
  libavfilter    1.19. 0 /  1.19. 0
  libswscale     0.11. 0 /  0.11. 0
  libpostproc   51. 2. 0 / 51. 2. 0
[matroska @ 0x1d25670]Unknown entry 0xF0
[matroska @ 0x1d25670]Unknown entry 0xB2
[matroska @ 0x1d25670]Unknown entry 0xF0
    Last message repeated 4 times

    ... Lots of these messages repeatedly ...

[matroska @ 0x1d25670]Unknown entry 0x4484
    Last message repeated 20 times
[matroska @ 0x1d25670]Estimating duration from bitrate, this may be inaccurate
Input #0, matroska, from 'movie.mkv':
  Metadata:
    doctype         : matroska
  Duration: 00:29:16.80, start: 0.000000, bitrate: N/A
    Stream #0.0: Video: h264, yuv420p, 1280x720 [PAR 1:1 DAR 16:9], 23.98 fps, 23.98 tbr, 1k tbn, 47.95 tbc
    Metadata:
      BPS-eng         : 2717320
      DURATION-eng    : 00:29:16.756000000
      NUMBER_OF_FRAMES-eng: 42120
      NUMBER_OF_BYTES-eng: 596708606
      _STATISTICS_WRITING_APP-eng: mkvmerge v7.2.0 ('On Every Street') 32bit built on Sep 13 2014 15:42:11
      _STATISTICS_WRITING_DATE_UTC-eng: 2017-08-07 04:16:16
      _STATISTICS_TAGS-eng: BPS DURATION NUMBER_OF_FRAMES NUMBER_OF_BYTES
    Stream #0.1: Audio: aac, 48000 Hz, stereo, s16
    Metadata:
      BPS-eng         : 189376
      DURATION-eng    : 00:29:16.806000000
      NUMBER_OF_FRAMES-eng: 82351
      NUMBER_OF_BYTES-eng: 41587196
      _STATISTICS_WRITING_APP-eng: mkvmerge v7.2.0 ('On Every Street') 32bit built on Sep 13 2014 15:42:11
      _STATISTICS_WRITING_DATE_UTC-eng: 2017-08-07 04:16:16
      _STATISTICS_TAGS-eng: BPS DURATION NUMBER_OF_FRAMES NUMBER_OF_BYTES
    Stream #0.2: Subtitle: 0x0000
    Metadata:
      BPS-eng         : 149
      DURATION-eng    : 00:27:59.495000000
      NUMBER_OF_FRAMES-eng: 530
      NUMBER_OF_BYTES-eng: 31487
      _STATISTICS_WRITING_APP-eng: mkvmerge v7.2.0 ('On Every Street') 32bit built on Sep 13 2014 15:42:11
      _STATISTICS_WRITING_DATE_UTC-eng: 2017-08-07 04:16:16
      _STATISTICS_TAGS-eng: BPS DURATION NUMBER_OF_FRAMES NUMBER_OF_BYTES
Unable to find a suitable output format for 'subs.srt'