title: How do I use youtube-dl's --add-header option?
body: <p>I'm trying to add a custom header using youtube-dl, a popular video downloader with command line interface.</p>
  
  <p>I'm using PowerShell (or CMD) on Windows 10.</p>
  
  <p><a href="https://github.com/ytdl-org/youtube-dl/blob/master/README.md#readme" rel="noreferrer">The official documentation</a> says like the following but I can't seem to use it properly.</p>
  
  <blockquote>
    <p>--add-header FIELD:VALUE<br>
                                     Specify a custom HTTP header and its value,
                                     separated by a colon ':'. You can use this
                                     option multiple times</p>
  </blockquote>
  
  <p>I'm trying to add multiple headers for the request like:</p>
  
  <pre>
  "Accept-Encoding": "identity;q=1, *;q=0",
  "Range": "bytes=6488064-",
  "Referer": "https://avideosite.net/video/0123456",
  "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/75.0.3770.80 Safari/537.36"
  </pre>
  
  <p>But when I tried something like</p>
  
  <pre><code>start youtube-dl --add-header "Accept-Encoding":"identity;q=1, *;q=0" --add-header "Range":"bytes=6488064-" --add-header "Referer":"https://avideosite.net/video/0123456" --add-header "User-Agent":"Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/75.0.3770.80 Safari/537.36" "http://11.22.333.444:8280/abcdefg=.mp4?st=97WbFiADB5Hla7Y-fZx58g&amp;e=1560574126"
  </code></pre>
  
  <p>It doesn't work and throws an error like this: </p>
  
  <pre>
  Start-Process : A positional parameter cannot be found that accepts argument
  'Accept-Encoding'.
  At line:1 char:1
  + start youtube-dl --add-header "Accept-Encoding":"identity;q=1, *;q=0" ...
  + ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      + CategoryInfo          : InvalidArgument: (:) [Start-Process], ParameterBindingException
      + FullyQualifiedErrorId : PositionalParameterNotFound,Microsoft.PowerShell.Commands.StartProcessCommand
  </pre>
  
  <p>What am I doing wrong?</p>
  
  <p>Also, is there a proper way to put it into Python script using <code>youtube_dl</code> library?</p>