Add get_ue_golomb_31()

Originally committed as revision 16298 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/golomb.h

@@ -74,6 +74,23 @@ static inline int get_ue_golomb(GetBitContext *gb){
     }
 }
 
+ /**
+ * read unsigned exp golomb code, constraint to a max of 31
+ */
+static inline int get_ue_golomb_31(GetBitContext *gb){
+    unsigned int buf;
+
+    OPEN_READER(re, gb);
+    UPDATE_CACHE(re, gb);
+    buf=GET_CACHE(re, gb);
+
+    buf >>= 32 - 9;
+    LAST_SKIP_BITS(re, gb, ff_golomb_vlc_len[buf]);
+    CLOSE_READER(re, gb);
+
+    return ff_ue_golomb_vlc_code[buf];
+}
+
 static inline int svq3_get_ue_golomb(GetBitContext *gb){
     uint32_t buf;