Mencoder is a companion program to the MPlayer media player that can be used to encode or transform any audio or video stream that MPlayer can read. See the RestrictedFormats wiki page for instructions for enabling non-free formats in MPlayer and gmplayer. For more information visit the MPlayer web site.

Step 1. Install MenCoder and MPlayer

CentOS/RHEL and Fedora users, make sure that you have enabled ATrpms repository in system. Let’s begin installing MPlayer & Mencoder as per your operating system.

For CentOS/RHEL and Fedora:
# yum install mencoder
For Ubuntu and Debian:
$ sudo apt-get update
$ sudo apt-get install mencoder

Step 2. Check Audio/Video Codes

After successfully installing Mencoder, let’s check the available audio/video codes

Video Codecs:
$ mencoder -ovc help

MEncoder svn r34540 (Ubuntu), built with gcc-4.6 (C) 2000-2012 MPlayer Team

Available codecs:
   copy     - frame copy, without re-encoding. Doesn't work with filters.
   frameno  - special audio-only file for 3-pass encoding, see DOCS.
   raw      - uncompressed video. Use fourcc option to set format explicitly.
   nuv      - nuppel video
   lavc     - libavcodec codecs - best quality!
   vfw      - VfW DLLs, read DOCS/HTML/en/encoding-guide.html.
   qtvideo  - QuickTime DLLs, currently only SVQ1/3 are supported.
   xvid     - XviD encoding
   x264     - H.264 encoding
Audio Codecs:
$ mencoder -oac help
MEncoder svn r34540 (Ubuntu), built with gcc-4.6 (C) 2000-2012 MPlayer Team

Available codecs:
   copy     - frame copy, without re-encoding (useful for AC3)
   pcm      - uncompressed PCM audio
   mp3lame  - cbr/abr/vbr MP3 using libmp3lame
   lavc     - FFmpeg audio encoder (MP2, AC3, ...)