ENH: Add a ffmpeg cmake module

CMake/FindFFMPEG.cmake

+#
+# Find the native FFMPEG includes and library
+#
+# This module defines
+# FFMPEG_INCLUDE_DIR, where to find avcodec.h, avformat.h ...
+# FFMPEG_LIBRARIES, the libraries to link against to use FFMPEG.
+# FFMPEG_FOUND, If false, do not try to use FFMPEG.
+
+# also defined, but not for general use are
+# FFMPEG_LIBRARY, where to find the FFMPEG library.
+# This is usefull to do it this way so that we can always add more libraries
+# if needed to FFMPEG_LIBRARIES if ffmpeg ever changes...
+
+FIND_PATH(FFMPEG_INCLUDE_DIR ffmpeg/avformat.h
+  /usr/local/include
+  /usr/include
+)
+
+FIND_LIBRARY(FFMPEG_LIBRARY avformat
+  /usr/local/lib
+  /usr/lib
+)
+
+IF(FFMPEG_INCLUDE_DIR)
+  IF(FFMPEG_LIBRARY)
+    SET( FFMPEG_FOUND "YES" )
+    SET( FFMPEG_LIBRARIES ${FFMPEG_LIBRARY} )
+  ENDIF(FFMPEG_LIBRARY)
+ENDIF(FFMPEG_INCLUDE_DIR)
+
+