title: FFMPEG sensible defaults
body: <p>I'm using ffmpeg to watermark videos with a PNG file using vfilters like so:</p>
  
  <pre><code>ffmpeg -i 26.wmv -vcodec libx264 -acodec copy -vf "movie=logo.png [watermark]; [in][watermark] overlay=10:10 [out]" 26_w.mkv
  </code></pre>
  
  <p>However, the input files are all of different quality/bitrates, and I want the output files to be of similar quality/bitrate to the input files. How would I achieve this?
  Also, I know almost nothing about ffmpeg, so are there any options which would be sensible to set to give a good quality:filesize ratio?</p>