Index: DOCS/man/en/mplayer.1
===================================================================
RCS file: /cvsroot/mplayer/main/DOCS/man/en/mplayer.1,v
retrieving revision 1.1214
diff -u -r1.1214 mplayer.1
--- DOCS/man/en/mplayer.1	24 Jan 2006 22:44:34 -0000	1.1214
+++ DOCS/man/en/mplayer.1	27 Jan 2006 22:40:01 -0000
@@ -6897,8 +6897,11 @@
 .TP
 .B brd_scale=<0\-10>
 Downscales frames for dynamic B-frame decision (default: 0).
-Speed should increase by a factor of 4 every time brd_scale is increased
-by 1.
+Each time brd_scale is increased by one, the frame dimensions are
+divided by two, which improves speed by a factor of four.
+A given brd_scale value will work only if both dimensions can be evenly
+divided by two that many times.
+In other words, the dimensions must both be a multiple of 2^brd_scale.
 .
 .TP
 .B bidir_refine=<0\-4>