libavfilter/libmpcodecs: add vf_stereo3d support

(code from mplayer see their svn for detailed authorship)
parameters must be integers as we do not have mplayers parser
also the stuff passed to it through non constant globals is not supported
this should be fixed in mplayer first.
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavfilter/Makefile

@@ -134,6 +134,7 @@ OBJS-$(CONFIG_MP_FILTER) += libmpcodecs/vf_smartblur.o
 OBJS-$(CONFIG_MP_FILTER) += libmpcodecs/vf_softpulldown.o
 OBJS-$(CONFIG_MP_FILTER) += libmpcodecs/vf_softskip.o
 OBJS-$(CONFIG_MP_FILTER) += libmpcodecs/vf_spp.o
+OBJS-$(CONFIG_MP_FILTER) += libmpcodecs/vf_stereo3d.o
 OBJS-$(CONFIG_MP_FILTER) += libmpcodecs/vf_swapuv.o
 OBJS-$(CONFIG_MP_FILTER) += libmpcodecs/vf_telecine.o
 OBJS-$(CONFIG_MP_FILTER) += libmpcodecs/vf_tile.o

libavfilter/vf_mp.c

@@ -237,6 +237,7 @@ static const vf_info_t* const filters[]={
     &vf_info_softpulldown,
     &vf_info_softskip,
     &vf_info_spp,
+    &vf_info_stereo3d,
     &vf_info_swapuv,
     &vf_info_telecine,
     &vf_info_tile,
@@ -265,7 +266,6 @@ lavcdeint
 noformat
 pp
 scale
-stereo3d
 tfields
 vo
 yadif