title: Using FFmpeg to create a smooth video slideshow from images
body: <p>a quick question for FFmpeg guru's</p>
  
  <p>I'm just trying to create a very quick slideshow of lots of images, and am experimenting with 4 or 5 per second at the moment.
  Problem is, it's lagging after a few images and not displaying them in a consistent manner, and I'm not sure what setting I need to change/get right to make it appear smooth.</p>
  
  <p>From what I understand -r dictates how many frames per second, so 1/0.20 should produce 5 frames per second.
  I have a suspicion that the format used may dictate 24 frames a second or something which is causing the momentary hickup.</p>
  
  <p>This example produces a video that goes something like... 1.2.3.4.pause.1.2.3.4.pause</p>
  
  <p>"C:\Program Files\ffmpeg\bin\ffmpeg.exe" -f concat -r 1/0.20 -i 1.txt -s 1280x960 -vf format=yuv420p video18.mp4</p>
  
  <p>And this example goes something like.. 1.2.pause.1.2.pause.</p>
  
  <p>"C:\Program Files\ffmpeg\bin\ffmpeg.exe" -f concat -r 1/0.25 -i 1.txt -s 1280x960 -vf format=yuv420p video19.mp4</p>
  
  <p>Any ideas?</p>