ffplay: time counter starts from 8s with wavpack file

[ami_stuff]

​http://www1.datafilehost.com/d/4fcb2b2d

C:\>ffplay test.wv
ffplay version N-54178-gbbe26ef Copyright (c) 2003-2013 the FFmpeg developers
  built on Jun 24 2013 17:10:38 with gcc 4.7.3 (GCC)
  configuration: --enable-gpl --enable-version3 --disable-w32threads --enable-av
isynth --enable-bzlib --enable-fontconfig --enable-frei0r --enable-gnutls --enab
le-iconv --enable-libass --enable-libbluray --enable-libcaca --enable-libfreetyp
e --enable-libgsm --enable-libilbc --enable-libmodplug --enable-libmp3lame --ena
ble-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-l
ibopus --enable-librtmp --enable-libschroedinger --enable-libsoxr --enable-libsp
eex --enable-libtheora --enable-libtwolame --enable-libvo-aacenc --enable-libvo-
amrwbenc --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libxavs --
enable-libxvid --enable-zlib
  libavutil      52. 37.101 / 52. 37.101
  libavcodec     55. 17.100 / 55. 17.100
  libavformat    55.  9.100 / 55.  9.100
  libavdevice    55.  2.100 / 55.  2.100
  libavfilter     3. 77.101 /  3. 77.101
  libswscale      2.  3.100 /  2.  3.100
  libswresample   0. 17.102 /  0. 17.102
  libpostproc    52.  3.100 / 52.  3.100
Input #0, wv, from 'test.wv':    0B f=0/0
  Duration: 00:00:30.01, start: 0.000000, bitrate: 891 kb/s
    Stream #0:0: Audio: wavpack, 44100 Hz, stereo, s16p
   8.61 M-A:  0.000 fd=   0 aq=  671KB vq=    0KB sq=    0B f=0/0

[Carl Eugen Hoyos]

Regression since 9684d7f

[Carl Eugen Hoyos]

Fixed by Marton.