Add pad filter.

Originally committed as revision 23046 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavfilter/Makefile

@@ -19,6 +19,7 @@ OBJS-$(CONFIG_CROP_FILTER)                   += vf_crop.o
 OBJS-$(CONFIG_FORMAT_FILTER)                 += vf_format.o
 OBJS-$(CONFIG_NOFORMAT_FILTER)               += vf_format.o
 OBJS-$(CONFIG_NULL_FILTER)                   += vf_null.o
+OBJS-$(CONFIG_PAD_FILTER)                    += vf_pad.o
 OBJS-$(CONFIG_PIXELASPECT_FILTER)            += vf_aspect.o
 OBJS-$(CONFIG_SCALE_FILTER)                  += vf_scale.o
 OBJS-$(CONFIG_SLICIFY_FILTER)                += vf_slicify.o

libavfilter/allfilters.c

@@ -39,6 +39,7 @@ void avfilter_register_all(void)
     REGISTER_FILTER (FORMAT,      format,      vf);
     REGISTER_FILTER (NOFORMAT,    noformat,    vf);
     REGISTER_FILTER (NULL,        null,        vf);
+    REGISTER_FILTER (PAD,         pad,         vf);
     REGISTER_FILTER (PIXELASPECT, pixelaspect, vf);
     REGISTER_FILTER (SCALE,       scale,       vf);
     REGISTER_FILTER (SLICIFY,     slicify,     vf);