title: Capture video using FFMPEG without frozen image effect
body: <p>Anyone could help me? Have been trying to record video from an RTSP server using FFMPEG but somehow the video result has many frozen images (couldn't be used for any people detection) - the people look similar to this:
  <a href="https://i.stack.imgur.com/mrPPT.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/mrPPT.png" alt="enter image description here"></a></p>
  
  <p>Here is the code I used:</p>
  
  <blockquote>
    <p>ffmpeg -i rtsp://10.10.10.10/encoder1 -b:v 1024k -s 640x480 -an -t 60 -r 12.5 output.mp4</p>
  </blockquote>
  
  <p>What I have done so far?
  - Recorded the video in smaller dimension instead of original one
  - No audio and lower FPS
  - Even only record from two IP sources on a machine</p>
  
  <p>But still didn't get any luck yet. Anyone ever experience this?</p>