diff --git a/media/libtheora/lib/dec/decode.c b/media/libtheora/lib/dec/decode.c
--- a/media/libtheora/lib/dec/decode.c
+++ b/media/libtheora/lib/dec/decode.c
@@ -1803,8 +1803,8 @@
 
 static void oc_dering_block(unsigned char *_idata,int _ystride,int _b,
  int _dc_scale,int _sharp_mod,int _strong){
-  static const int     MOD_MAX[2]={24,32};
-  static const int     MOD_SHIFT[2]={1,0};
+  static const int     OCDB_MOD_MAX[2]={24,32};
+  static const int     OCDB_MOD_SHIFT[2]={1,0};
   const unsigned char *psrc;
   const unsigned char *src;
   const unsigned char *nsrc;
@@ -1814,14 +1814,14 @@
   int                  mod_hi;
   int                  by;
   int                  bx;
-  mod_hi=OC_MINI(3*_dc_scale,MOD_MAX[_strong]);
+  mod_hi=OC_MINI(3*_dc_scale,OCDB_MOD_MAX[_strong]);
   dst=_idata;
   src=dst;
   psrc=src-(_ystride&-!(_b&4));
   for(by=0;by<9;by++){
     for(bx=0;bx<8;bx++){
       int mod;
-      mod=32+_dc_scale-(abs(src[bx]-psrc[bx])<<MOD_SHIFT[_strong]);
+      mod=32+_dc_scale-(abs(src[bx]-psrc[bx])<<OCDB_MOD_SHIFT[_strong]);
       vmod[(by<<3)+bx]=mod<-64?_sharp_mod:OC_CLAMPI(0,mod,mod_hi);
     }
     psrc=src;
@@ -1833,7 +1833,7 @@
     src=nsrc;
     for(by=0;by<8;by++){
       int mod;
-      mod=32+_dc_scale-(abs(*src-*psrc)<<MOD_SHIFT[_strong]);
+      mod=32+_dc_scale-(abs(*src-*psrc)<<OCDB_MOD_SHIFT[_strong]);
       hmod[(bx<<3)+by]=mod<-64?_sharp_mod:OC_CLAMPI(0,mod,mod_hi);
       psrc+=_ystride;
       src+=_ystride;
