title: ffmpeg leak detection
body: <p>I'm currently doing some conversion work with ffmpeg building with gcc under mSys for the DLLs and some plain C wrapper code which I'm then calling from C#. </p>
  
  <p>If I use the MS crtdbg.h I'm not now showing any memory leaks (I did have a couple) BUT I'd like to check if I've left behind a leak within the ffmpeg code which I assume is using a gcc libc library.</p>
  
  <p>For example I was using some AVDictionary objects which I'd forgotten to clearup afterwards, I'm worried there may be some more elsewhere that I've missed.</p>
  
  <p>Anyone got any advice on how to confirm that I'm not leaking memory in the ffmpeg DLLs?</p>