Ministry of English Composition edits

Originally committed as revision 11597 to svn://svn.ffmpeg.org/ffmpeg/trunk

doc/optimization.txt

@@ -28,16 +28,17 @@ NOTE: If you still don't understand some function, ask at our mailing list!!!
 (http://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel)
 
 
-What speedup justifies an optimizetion?
----------------------------------------
-Normaly with clean&simple optimizations and widely used codecs a overall
-speedup of the affected codec of 0.1% is enough. These speedups accumulate
-and can make a big difference after a while ...
-Also if none of the following gets worse and at least one gets better then an
-optimization is always a good idea even if the overall gain is less than 0.1%
-(speed, binary code size, source size, source readability)
-For obscure codecs noone uses, the goal is more toward keeping the code clean
-small and readable than to make it 1% faster.
+When is an optimization justified?
+----------------------------------
+Normally, clean & simple optimizations on widely used codecs can achieve
+an overall speedup of 0.1%. These speedups accumulate and can make a big
+difference after awhile. Also, if none of the following factors get
+worse due to an optimization -- speed, binary code size, source size,
+source readability -- and at least one factor improves, then an
+optimization is always a good idea even if the overall gain is less than
+0.1%. For obscure codecs that are not often used, the goal is more
+toward keeping the code clean, small, and readable than to make it 1%
+faster.
 
 
 WTF is that function good for ....: