diff --git a/src/osgPlugins/ffmpeg/FFmpegDecoderVideo.cpp b/src/osgPlugins/ffmpeg/FFmpegDecoderVideo.cpp
index 1e4b56ef0..450377196 100644
--- a/src/osgPlugins/ffmpeg/FFmpegDecoderVideo.cpp
+++ b/src/osgPlugins/ffmpeg/FFmpegDecoderVideo.cpp
@@ -240,8 +240,8 @@ int FFmpegDecoderVideo::convert(AVPicture *dst, int dst_pix_fmt, AVPicture *src,
 #ifdef USE_SWSCALE
     if (m_swscale_ctx==0)
     {
-        m_swscale_ctx = sws_getContext(src_width, src_height, src_pix_fmt,
-                                      src_width, src_height, dst_pix_fmt,                                    
+        m_swscale_ctx = sws_getContext(src_width, src_height, (PixelFormat) src_pix_fmt,
+                                      src_width, src_height, (PixelFormat) dst_pix_fmt,
                                       /*SWS_BILINEAR*/ SWS_BICUBIC, NULL, NULL, NULL);
     }
     
diff --git a/src/osgPlugins/ffmpeg/ReaderWriterFFmpeg.cpp b/src/osgPlugins/ffmpeg/ReaderWriterFFmpeg.cpp
index 65afe135b..ee9d93795 100644
--- a/src/osgPlugins/ffmpeg/ReaderWriterFFmpeg.cpp
+++ b/src/osgPlugins/ffmpeg/ReaderWriterFFmpeg.cpp
@@ -36,7 +36,8 @@ public:
         supportsExtension("ogg", "Theora movie format");
         supportsExtension("mpg", "Mpeg movie format");
         supportsExtension("mpv", "Mpeg movie format");
-        supportsExtension("wmv", "");
+        supportsExtension("wmv", "Windows Media Video format");
+        supportsExtension("mkv", "Matroska");
 
         // Register all FFmpeg formats/codecs
         av_register_all();