title: LNK2019: unresolved external symbol __imp__dclass
body: <p>I am trying to build ffmpeg on visual studio for ARM architecture. I run into following linker errors:</p>
  
  <pre><code>Error   58  error LNK2019: unresolved external symbol __imp__dclass referenced in function mov_read_tkhd avformat.lib(mov.o)
  
  Error   59  error LNK2001: unresolved external symbol __imp__dclass avformat.lib(thp.o) 
  
  Error   60  error LNK2001: unresolved external symbol __imp__dclass avutil.lib(rational.o)
  
  Error   61  error LNK2001: unresolved external symbol __imp__dclass avutil.lib(eval.o)
  </code></pre>
  
  <p>What is __imp__dclass and where it is defined in Visual Studio / FFMPEG?</p>
  
  <p>I get the following when I do "dumpbin /symbols mov.o"</p>
  
  <pre><code>22D 00000000 UNDEF  notype       External     | __imp__dclass
  </code></pre>
  
  <p>Any ideas?</p>