>ffmpeg -i 'C:\Program Files (x86)\GOG.com\Total Annihilation\tamus\4.mp3' -lavfi showspectrum c:\c\
wavetest.jpg
ffmpeg version N-76822-g12a419d Copyright (c) 2000-2015 the FFmpeg developers
  built with gcc 5.2.0 (GCC)
  configuration: --enable-gpl --enable-version3 --disable-w32threads --enable-avisynth --enable-bzli
b --enable-fontconfig --enable-frei0r --enable-gnutls --enable-iconv --enable-libass --enable-libblu
ray --enable-libbs2b --enable-libcaca --enable-libdcadec --enable-libfreetype --enable-libgme --enab
le-libgsm --enable-libilbc --enable-libmodplug --enable-libmp3lame --enable-libopencore-amrnb --enab
le-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-librtmp --enable-libschroedinger
 --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libtwolame --enable-libvidstab --ena
ble-libvo-aacenc --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwavpack --en
able-libwebp --enable-libx264 --enable-libx265 --enable-libxavs --enable-libxvid --enable-libzimg --
enable-lzma --enable-decklink --enable-zlib
  libavutil      55.  9.100 / 55.  9.100
  libavcodec     57. 16.100 / 57. 16.100
  libavformat    57. 19.100 / 57. 19.100
  libavdevice    57.  0.100 / 57.  0.100
  libavfilter     6. 15.100 /  6. 15.100
  libswscale      4.  0.100 /  4.  0.100
  libswresample   2.  0.101 /  2.  0.101
  libpostproc    54.  0.100 / 54.  0.100
[mp3 @ 0000000000444240] Skipping 0 bytes of junk at 0.
[mp3 @ 0000000000444240] Estimating duration from bitrate, this may be inaccurate
Input #0, mp3, from 'C:\Program Files (x86)\GOG.com\Total Annihilation\tamus\4.mp3':
  Metadata:
    title           : Attack!!!
    artist          : Jeremy Soule
    album           : Total Annihilation
    date            : 1997
    track           : 4
  Duration: 00:02:36.89, start: 0.000000, bitrate: 320 kb/s
    Stream #0:0: Audio: mp3, 44100 Hz, stereo, s16p, 320 kb/s
File 'c:\c\wavetest.jpg' already exists. Overwrite ? [y/N] y
[mjpeg @ 0000000000475400] removing common factors from framerate
Output #0, image2, to 'c:\c\wavetest.jpg':
  Metadata:
    title           : Attack!!!
    artist          : Jeremy Soule
    album           : Total Annihilation
    date            : 1997
    track           : 4
    encoder         : Lavf57.19.100
    Stream #0:0: Video: mjpeg, yuvj444p(pc), 640x512 [SAR 1:1 DAR 5:4], q=2-31, 200 kb/s, 43.07 fps,
 43.07 tbn, 43.07 tbc
    Metadata:
      encoder         : Lavc57.16.100 mjpeg
Stream mapping:
  Stream #0:0 (mp3) -> showspectrum
  showspectrum -> Stream #0:0 (mjpeg)
Press [q] to stop, [?] for help
[image2 @ 0000000000461d40] Could not get frame filename number 2 from pattern 'c:\c\wavetest.jpg' (
either set updatefirst or use a pattern like %03d within the filename pattern)
av_interleaved_write_frame(): Invalid argument
frame=    2 fps=0.0 q=1.6 Lsize=N/A time=00:00:00.04 bitrate=N/A
video:19kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown
Conversion failed!