title: ffmepg video from uneven sequence of png images
body: <p>I'm going to make a video from series of screenshots (.png files). For each screenshot there is assosiated timestamp information about when it was taken. The time intervals between screenshots may vary and it's highly desired to preserve that difference in the video. </p>
  
  <p>Is there a way to use single <code>ffmpeg</code> command/API providing to it sequence of image + time (or frame) offset and getting one video file as output? 
  By now I have to generate short video files of custom length for each image, and then merge them manually:</p>
  
  <pre><code>ffmpeg -y -loop 1 -i image1.png -c:v libx264 -t 1.52 video1.avi
  ffmpeg -y -loop 1 -i image2.png -c:v libx264 -t 2.28 video2.avi
  ...
  ffmpeg -y -loop 1 -i imageN.png -c:v libx264 -t 1.04 videoN.avi
  
  
  ffmpeg -i "concat:video1.avi|video2.avi|...videoN.avi" -c copy output.avi
  </code></pre>
  
  <p>This is quite ok, while intervals are large, but the whole approach seems to me a bit fragile.</p>