Make av_class a pointer to const.

Patch by Takis.

Originally committed as revision 26210 to svn://svn.mplayerhq.hu/mplayer/trunk/libswscale

libswscale/swscale.c

@@ -274,7 +274,7 @@ static const AVOption options[] = {
 #undef VE
 #undef DEFAULT
 
-static AVClass sws_context_class = { "SWScaler", sws_context_to_name, options };
+static const AVClass sws_context_class = { "SWScaler", sws_context_to_name, options };
 
 const char *sws_format_name(enum PixelFormat format)
 {

libswscale/swscale_internal.h

@@ -42,7 +42,7 @@ typedef struct SwsContext{
     /**
      * info on struct for av_log
      */
-    AVClass *av_class;
+    const AVClass *av_class;
 
     /**
      * Note that src, dst, srcStride, dstStride will be copied in the