lavfi: port IVTC filters from vapoursynth.

Changelog

@@ -22,6 +22,7 @@ version <next>:
 - telecine filter
 - new interlace filter
 - smptehdbars source
+- inverse telecine filters (fieldmatch and decimate)
 
 
 version 1.2:

libavfilter/Makefile

@@ -109,6 +109,7 @@ OBJS-$(CONFIG_COPY_FILTER)                   += vf_copy.o
 OBJS-$(CONFIG_CROP_FILTER)                   += vf_crop.o
 OBJS-$(CONFIG_CROPDETECT_FILTER)             += vf_cropdetect.o
 OBJS-$(CONFIG_CURVES_FILTER)                 += vf_curves.o
+OBJS-$(CONFIG_DECIMATE_FILTER)               += vf_decimate.o
 OBJS-$(CONFIG_DELOGO_FILTER)                 += vf_delogo.o
 OBJS-$(CONFIG_DESHAKE_FILTER)                += vf_deshake.o
 OBJS-$(CONFIG_DRAWBOX_FILTER)                += vf_drawbox.o
@@ -116,6 +117,7 @@ OBJS-$(CONFIG_DRAWTEXT_FILTER)               += vf_drawtext.o
 OBJS-$(CONFIG_EDGEDETECT_FILTER)             += vf_edgedetect.o
 OBJS-$(CONFIG_FADE_FILTER)                   += vf_fade.o
 OBJS-$(CONFIG_FIELD_FILTER)                  += vf_field.o
+OBJS-$(CONFIG_FIELDMATCH_FILTER)             += vf_fieldmatch.o
 OBJS-$(CONFIG_FIELDORDER_FILTER)             += vf_fieldorder.o
 OBJS-$(CONFIG_FORMAT_FILTER)                 += vf_format.o
 OBJS-$(CONFIG_FRAMESTEP_FILTER)              += vf_framestep.o

libavfilter/allfilters.c

@@ -107,6 +107,7 @@ void avfilter_register_all(void)
     REGISTER_FILTER(CROP,           crop,           vf);
     REGISTER_FILTER(CROPDETECT,     cropdetect,     vf);
     REGISTER_FILTER(CURVES,         curves,         vf);
+    REGISTER_FILTER(DECIMATE,       decimate,       vf);
     REGISTER_FILTER(DELOGO,         delogo,         vf);
     REGISTER_FILTER(DESHAKE,        deshake,        vf);
     REGISTER_FILTER(DRAWBOX,        drawbox,        vf);
@@ -114,6 +115,7 @@ void avfilter_register_all(void)
     REGISTER_FILTER(EDGEDETECT,     edgedetect,     vf);
     REGISTER_FILTER(FADE,           fade,           vf);
     REGISTER_FILTER(FIELD,          field,          vf);
+    REGISTER_FILTER(FIELDMATCH,     fieldmatch,     vf);
     REGISTER_FILTER(FIELDORDER,     fieldorder,     vf);
     REGISTER_FILTER(FORMAT,         format,         vf);
     REGISTER_FILTER(FPS,            fps,            vf);

libavfilter/version.h

@@ -29,7 +29,7 @@
 #include "libavutil/avutil.h"
 
 #define LIBAVFILTER_VERSION_MAJOR  3
-#define LIBAVFILTER_VERSION_MINOR  55
+#define LIBAVFILTER_VERSION_MINOR  56
 #define LIBAVFILTER_VERSION_MICRO 100
 
 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \