Sun Apr 10, 2016 5:07 am by talanmawr
			
			
			For what it's worth...here's a FFMPEG- -i of an MKV file that won't play:
ffmpeg version 2.4.git Copyright (c) 2000-2014 the FFmpeg developers
  built on Nov 19 2014 22:12:09 with gcc 4.7.2 (GCC)
  configuration: --enable-static --disable-shared --disable-ffplay --disable-ffserver --enable-memalign-hack --enable-libmp3lame --enable-libass --enable-librtmp --enable-fontconfig --enable-libfreetype --enable-zlib --enable-libx264 --enable-libspeex --extra-libs='-lrtmp -lpolarssl -lws2_32 -lwinmm -lexpat -lfreetype -lfribidi -lz' --arch=x86 --enable-runtime-cpudetect --enable-pthreads --target-os=mingw32 --cross-prefix=i686-w64-mingw32- --enable-gpl --pkg-config=pkg-config
  libavutil      54. 14.100 / 54. 14.100
  libavcodec     56. 12.101 / 56. 12.101
  libavformat    56. 14.100 / 56. 14.100
  libavdevice    56.  3.100 / 56.  3.100
  libavfilter     5.  2.103 /  5.  2.103
  libswscale      3.  1.101 /  3.  1.101
  libswresample   1.  1.100 /  1.  1.100
  libpostproc    53.  3.100 / 53.  3.100
The device just complains that it's not a playable format.