Add support for newer display units in MatroskaParser (#378)

Author: mzn928

src/MatroskaParser.c

@@ -1169,7 +1169,7 @@ static void parseVideoInfo(MatroskaFile *mf,uint64_t toplen,struct TrackInfo *ti
       break;
     case 0x54b2: // DisplayUnit
       v = readUInt(mf,(unsigned)len);
-      if (v>2)
+      if (v>4)
 	errorjmp(mf,"Invalid DisplayUnit: %d",(int)v);
       ti->AV.Video.DisplayUnit = (unsigned char)v;
       break;