nofew@NoClock ~/VIDEO $ ./ffmpeg -i MushVis_RAW.flv -vcodec libx265 -x265-params crf=22 -preset medium -movflags faststart -pix_fmt yuv420p -acodec copy OU265.mkv
ffmpeg version N-40545-ga8ad7e4-   http://johnvansickle.com/ffmpeg/    Copyright (c) 2000-2014 the FFmpeg developers
  built on Feb 25 2014 04:11:13 with gcc 4.8 (Debian 4.8.2-16)
  configuration: --enable-gpl --enable-version3 --disable-shared --disable-debug --enable-runtime-cpudetect --enable-libmp3lame --enable-libx264 --enable-libx265 --enable-libwebp --enable-libspeex --enable-libvorbis --enable-libvpx --enable-libfreetype --enable-libxvid --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libtheora --enable-libvo-aacenc --enable-libvo-amrwbenc --enable-gray --enable-libopenjpeg --enable-libopus --disable-ffserver
  libavutil      52. 66.100 / 52. 66.100
  libavcodec     55. 52.102 / 55. 52.102
  libavformat    55. 33.100 / 55. 33.100
  libavdevice    55. 10.100 / 55. 10.100
  libavfilter     4.  1.103 /  4.  1.103
  libswscale      2.  5.101 /  2.  5.101
  libswresample   0. 18.100 /  0. 18.100
  libpostproc    52.  3.100 / 52.  3.100
Input #0, flv, from 'MushVis_RAW.flv':
  Metadata:
    fileSize        : 22554014483
    audiochannels   : 2
    encoder         : Open Broadcaster Software v0.592b
  Duration: 00:07:09.00, start: 0.000000, bitrate: 420587 kb/s
    Stream #0:0: Video: h264 (High 4:4:4 Predictive), yuv420p(tv, bt709), 1920x1080, 204800 kb/s, 60 tbr, 1k tbn, 2k tbc
    Stream #0:1: Audio: mp3, 44100 Hz, stereo, s16p, 262 kb/s
File 'OU265.mkv' already exists. Overwrite ? [y/N] y
x265 [info]: using cpu capabilities: MMX2 SSE SSE2Fast SSSE3 SSE4.2 AVX
x265 [error]: Sample Aspect Ratio width must be greater than 0
[libx265 @ 0x45cb820] Cannot open libx265 encoder.
Output #0, matroska, to 'OU265.mkv':
  Metadata:
    fileSize        : 22554014483
    audiochannels   : 2
    encoder         : Open Broadcaster Software v0.592b
    Stream #0:0: Video: hevc, yuv420p, 1920x1080, q=2-31, 200 kb/s, 90k tbn, 60 tbc
    Stream #0:1: Audio: mp3, 44100 Hz, stereo, 262 kb/s
Stream mapping:
  Stream #0:0 -> #0:0 (h264 -> libx265)
  Stream #0:1 -> #0:1 (copy)
Error while opening encoder for output stream #0:0 - maybe incorrect parameters such as bit_rate, rate, width or height