We have to handle the callback object a bit different:
a) it needs a virtual destructor
b) we need to set the callback to NULL when we're done with the output
c) create a new one every time
https://bugzilla.gnome.org/show_bug.cgi?id=740616
Builds with MSVC, not tested in MinGW or anything else. Added
COM handling code, borrowed from dshowvideosink. Moved Linux
specific files to ./linux and added Windows specific files to
./win (generated from IDL files in VS9). Added macros to handle
BSTR and defined bool as BOOL. Fixes#655362.
Signed-off-by: David Schleef <ds@schleef.org>