title: GZipStream: Compressed file bigger than original
body: <p>I'm trying to use gzip streams in C# but it appears that the files after compression are bigger than before. 
  It's occurs when I working with .avi and .mkv files. But if I working with .txt and .html compressed file smaller than original.</p>
  
  <pre><code>using (MemoryStream output = new MemoryStream(blockToCompress.Length))
  {
       using (GZipStream cs = new GZipStream(output, CompressionMode.Compress))
       {
            cs.Write(blockToCompress, 0, blockToCompress.Length);
       }
  }
  </code></pre>
  
  <p>I solved this problem by checking the Framework (from 3.5 to 4.0) without editing the code.</p>