title: What is ffmpeg, avcodec, x264?
body: <p>From <a href="http://en.wikipedia.org/wiki/FFmpeg" rel="noreferrer">wiki</a>, I read that </p>
  
  <blockquote>
    <p>FFmpeg is a free software project that produces libraries and programs
    for handling multimedia data. The most notable parts of FFmpeg are
    libavcodec, an audio/video codec library used by several other
    projects, libavformat, an audio/video container mux and demux library,
    and the ffmpeg command line program for transcoding multimedia files.</p>
  </blockquote>
  
  <p>So ffmpeg is a wrapper of avcodec? And I often hear that people encode video with x264 using ffmpeg. So ffmpeg is also a wrapper of x264?</p>
  
  <p>How are they related ?</p>