title: what is the use of "mux." in pipeline command
body: <p>This pipeline encodes a test audio and video stream and muxes both into an FLV file.</p>
  
  <pre><code>gst-launch-1.0 -v flvmux name=mux ! filesink location=test.flv  audiotestsrc samplesperbuffer=44100 num-buffers=10 ! faac ! mux.  videotestsrc num-buffers=250 ! video/x-raw,framerate=25/1 ! x264enc ! mux.
  </code></pre>
  
  <p>I am not able to figure out what <code>mux.</code> actually does and use of dot in pipeline command during muxing,Can someone please explain or any doc for reference</p>