title: convert from avi to mp4 using ffmpeg
body: <p>I want to play an <code>avi</code> video format file in browsers using HTML5 video code. Since the 
  <code>avi</code> format file doesn't play in browsers i have to convert it into mp4 format file.</p>
  
  <p>For conversion i am using the <code>ffmpeg</code> code in Windows.</p>
  
  <p><code>ffmpeg -i  input.avi   OUTPUT.mp4</code></p>
  
  <p>The conversion of video is completed but the video codec and audio codec isn't valid thus it fails to play to play using video tag in <code>html5</code>.</p>
  
  <p>Please find me proper code which coverts the file.
  another conversion code i tried was.. <code>ffmpeg -i input.avi -c:v libx264 -preset slow -crf 22 -c:a libfaac -b:a 128k  OUTPUTAVINew.mp4</code> but i got error as libfaac unknown encoder 
  please help me out and even i downloaded the <code>**libfaac.dll**</code> but didn't work out
          `</p>