G:\>ffmpeg -i "input.mkv" -map 0:1 -af asetpts=0.91875*PTS target.wav
ffmpeg version N-66154-g1654ca7 Copyright (c) 2000-2014 the FFmpeg developers
  built on Sep  5 2014 22:10:38 with gcc 4.8.3 (GCC)
  configuration: --enable-gpl --enable-version3 --disable-w32threads --enable-avisynth --enable-bzlib --enable-fontconfig --enable-frei0r --enable-gnutls --enab
le-iconv --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libfreetype --enable-libgme --enable-libgsm --enable-libilbc --enable-lib
modplug --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-librtmp --enable-libschroedinge
r --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvo-aacenc --enable-libvo-amrwbenc --enable-libvorbis
 --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxavs --enable-libxvid --enable-decklink --enable-zlib
  libavutil      54.  7.100 / 54.  7.100
  libavcodec     56.  1.100 / 56.  1.100
  libavformat    56.  4.100 / 56.  4.100
  libavdevice    56.  0.100 / 56.  0.100
  libavfilter     5.  1.100 /  5.  1.100
  libswscale      3.  0.100 /  3.  0.100
  libswresample   1.  1.100 /  1.  1.100
  libpostproc    53.  0.100 / 53.  0.100
Guessed Channel Layout for  Input Stream #0.1 : stereo
Input #0, matroska,webm, from 'input.mkv':
  Metadata:
    encoder         : libmatroska 1.3.0
  Duration: 02:19:02.92, start: 0.012000, bitrate: 60722 kb/s
    Stream #0:0(ger): Video: lagarith (LAGS / 0x5347414C), yuv422p, 720x576, SAR 1:1 DAR 5:4, 25 fps, 25 tbr, 1k tbn, 1k tbc (default) (forced)
    Metadata:
      title           :
    Stream #0:1(ger): Audio: pcm_s16le, 48000 Hz, 2 channels, s16, 1536 kb/s (default) (forced)
    Metadata:
      title           : Audio
Output #0, wav, to 'target.wav':
  Metadata:
    ISFT            : Lavf56.4.100
    Stream #0:0(ger): Audio: pcm_s16le ([1][0][0][0] / 0x0001), 48000 Hz, stereo, s16, 1536 kb/s (default) (forced)
    Metadata:
      title           : Audio
      encoder         : Lavc56.1.100 pcm_s16le
Stream mapping:
  Stream #0:1 -> #0:0 (pcm_s16le (native) -> pcm_s16le (native))
Press [q] to stop, [?] for help
size= 1564416kB time=02:07:45.01 bitrate=1672.0kbits/s
video:0kB audio:1564416kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.000005%

G:\>ffprobe target.wav
ffprobe version N-66154-g1654ca7 Copyright (c) 2007-2014 the FFmpeg developers
  built on Sep  5 2014 22:10:38 with gcc 4.8.3 (GCC)
  configuration: --enable-gpl --enable-version3 --disable-w32threads --enable-avisynth --enable-bzlib --enable-fontconfig --enable-frei0r --enable-gnutls --enab
le-iconv --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libfreetype --enable-libgme --enable-libgsm --enable-libilbc --enable-lib
modplug --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-librtmp --enable-libschroedinge
r --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvo-aacenc --enable-libvo-amrwbenc --enable-libvorbis
 --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxavs --enable-libxvid --enable-decklink --enable-zlib
  libavutil      54.  7.100 / 54.  7.100
  libavcodec     56.  1.100 / 56.  1.100
  libavformat    56.  4.100 / 56.  4.100
  libavdevice    56.  0.100 / 56.  0.100
  libavfilter     5.  1.100 /  5.  1.100
  libswscale      3.  0.100 /  3.  0.100
  libswresample   1.  1.100 /  1.  1.100
  libpostproc    53.  0.100 / 53.  0.100
Input #0, wav, from 'target.wav':
  Metadata:
    encoder         : Lavf56.4.100
  Duration: 02:19:03.55, bitrate: 1536 kb/s
    Stream #0:0: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 48000 Hz, 2 channels, s16, 1536 kb/s