title: Strange FPS and frame number while re-encoding a video
body: <p>I am re-encoding a video using below command:</p>
  
  <pre><code>ffmpeg -i input.mp4 -q 20 output.avi
  </code></pre>
  
  <p>The video is 10 mins approx, i.e, it has around 18K frames. However, I am getting last frame number as 5061, but the re-encoded video is playing for all 10 mins. I don't understand the reason why it is showing such a low frame number. Below is last few lines of output. </p>
  
  <pre><code>frame= 5028 fps=143 q=20.0 size=   24863kB time=00:09:53.20 bitrate= 343.4kbits/s dup=0 drop=2087    
  Past duration 1.703728 too large
  Past duration 0.986687 too large
  Past duration 0.704277 too large
  Past duration 0.954399 too large
  Past duration 1.951469 too large
  Past duration 0.879509 too large
  Past duration 0.942192 too large  
  Past duration 0.815910 too large
  Past duration 0.785393 too large
  Past duration 0.792351 too large
  Past duration 0.644402 too large
  frame= 5061 fps=143 q=20.0 Lsize=   25493kB time=00:09:56.45 bitrate= 350.1kbits/s dup=0 drop=2098
  video:22458kB audio:2320kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 2.886272%
  </code></pre>
  
  <p>Edit: Here is the <a href="https://drive.google.com/a/cs.stonybrook.edu/file/d/0BxBwaoy1IbRXajFqd1VUaHZYakk/view?usp=sharing" rel="nofollow noreferrer">log</a></p>