title: How to add background image for text with text size on a video in FFmpeg?
body: <p>Is there way to add a background image under the text on the video in FFmpeg? </p>
  
  <p>I can add black background using 'box', but i need to add some certain image. I tried to use 'drawtext' on a image and then overlayed it on the video, but i don't know text's width and height for scaling the image.</p>
  
  <pre><code>"-i",
  "D:/AndroidProjects/Movies/VideoSamples/VideoShort1.mp4",
  "-i",
  "D:/AndroidProjects/Movies/ImageSamples/SampleImage.jpeg",
  "-filter_complex",
  "[0:v]drawtext=text='Example':fontcolor=#DB7093:fontsize=120:box=1:boxcolor=black@0.8:boxborderw=5:x='(w/2) - (tw/2)':y='h - ((h/2) - (th/2))",
  "-s",
  "1280x720",
  "-y",
  "D:/AndroidProjects/Movies/FFmpegSampleShort0.mp4"
  </code></pre>
  
  <p>I expect to get video with some image background under my text instead black color.
  <img src="https://i.imgur.com/9gBnOX2.png" alt="Final video"></p>