--enable-debug).
Fix from Jason Tackaberry for his previous -fPIC patch.
Originally committed as revision 19406 to svn://svn.mplayerhq.hu/mplayer/trunk/libswscale
the +-1 issue is limited to >2tap vertical filters, so bilinear upscale was unaffected
the new code is sometime faster sometimes slower but the difference is significant (~20%) so its optional and enabled with arnd=1
Originally committed as revision 19177 to svn://svn.mplayerhq.hu/mplayer/trunk/libswscale