title: Error on windows: opus not found using pkg-config
body: <p>When I try to compile <a href="https://github.com/telegramdesktop/tdesktop" rel="nofollow noreferrer">TelegramDesktop</a> code as shown as <a href="https://github.com/telegramdesktop/tdesktop/blob/dev/docs/building-msvc.md" rel="nofollow noreferrer">instructions</a> I have an error while I am installing FFMPEG.
  When I run
  <code>bash --login ../patches/build_ffmpeg_win.sh</code>command</p>
  <p>there is an error occured:
  <code>ERROR: opus not found using pkg-config If you think configure made a mistake, make sure you are using the latest version from Git.  If the latest version fails, report the problem to the ffmpeg-user@ffmpeg.org mailing list or IRC #ffmpeg on irc.freenode.net. Include the log file &quot;ffbuild/config.log&quot; produced by configure as this will help solve the problem.</code></p>
  <p>There are some instructions how to install ffmpeg on ubuntu but can't find how to solve this on Windows 10?
  Could anybody give me a hint?</p>