title: youtube-dl: What are the names of the config parameters when importing it as a library in Python?
body: <p>There seems to be <a href="https://github.com/rg3/youtube-dl/blob/master/README.md#embedding-youtube-dl" rel="nofollow noreferrer">almost no documentation</a> on the youtube-dl python library and the parameters for the cli tool don't translate 1:1... 
  I was able to find some parameters in the <code>YoutubeDL.py</code> that is linked in the Readme, but definitely not all of them. </p>
  
  <p>For instance, it is not clear to me how I can embed the video thumbnail into the video file I'm downloading. With the cli tool, I can use <code>--embed-thumbnail</code>, but when I try to use it in the config object it doesn't work. I don't even get an error</p>
  
  <pre><code> ydl_opts = {
       'format': 'bestvideo[height&lt;=480]+bestaudio[ext=m4a]/best', # works
       'embed-thumbnail': True, # not working
       'embedthumbnail': True, # not working
       'updatetime': False # works
   }
   youtube_dl.YoutubeDL(ydl_opts)
  </code></pre>
  
  <p>Here is a cli example that worked for me:</p>
  
  <pre><code>youtube-dl --format "bestvideo[height&lt;=480]+bestaudio[ext=m4a]/best" --embed-thumbnail https://www.youtube.com/watch?v=Co2KIYmaeTY
  </code></pre>
  
  <p>I verified it by running this on the resulting .mp4 file to extract the thumbnail:</p>
  
  <pre><code>AtomicParsley "thumbnail test-Co2KIYmaeTY.mp4" -E
  </code></pre>
  
  <p>This file is the closest I got: <a href="https://github.com/rg3/youtube-dl/blob/master/youtube_dl/postprocessor/embedthumbnail.py" rel="nofollow noreferrer">https://github.com/rg3/youtube-dl/blob/master/youtube_dl/postprocessor/embedthumbnail.py</a></p>
  
  <p>But I'm not sure what to make out of it...</p>