FATE: add a test for the gradfun filter

tests/fate/filter.mak

@@ -34,6 +34,9 @@ fate-filter-delogo: CMD = framecrc -i $(SAMPLES)/real/rv30.rm -vf delogo=show=0:
 
 FATE_FILTER-$(call FILTERDEMDEC, DELOGO, RM, RV30) += fate-filter-delogo
 
+FATE_FILTER_VSYNTH-$(CONFIG_GRADFUN_FILTER) += fate-filter-gradfun
+fate-filter-gradfun: CMD = framecrc -c:v pgmyuv -i $(SRC) -vf gradfun
+
 FATE_YADIF += fate-filter-yadif-mode0
 fate-filter-yadif-mode0: CMD = framecrc -flags bitexact -idct simple -i $(SAMPLES)/mpeg2/mpeg2_field_encoding.ts -vf yadif=0
 
@@ -42,5 +45,9 @@ fate-filter-yadif-mode1: CMD = framecrc -flags bitexact -idct simple -i $(SAMPLE
 
 FATE_FILTER-$(call FILTERDEMDEC, YADIF, MPEGTS, MPEG2VIDEO) += $(FATE_YADIF)
 
+$(FATE_FILTER_VSYNTH-yes): tests/vsynth1/00.pgm
+$(FATE_FILTER_VSYNTH-yes): SRC = $(TARGET_PATH)/tests/vsynth1/%02d.pgm
+FATE_AVCONV-$(call DEMDEC, IMAGE2, PGMYUV) += $(FATE_FILTER_VSYNTH-yes)
+
 FATE_SAMPLES_AVCONV += $(FATE_FILTER-yes)
-fate-filter: $(FATE_FILTER-yes)
+fate-filter: $(FATE_FILTER-yes) $(FATE_FILTER_VSYNTH-yes)

tests/ref/fate/filter-gradfun

@@ -0,0 +1,51 @@
+#tb 0: 1/25
+0,          0,          0,        1,   152064, 0xaebf898f
+0,          1,          1,        1,   152064, 0x217b6560
+0,          2,          2,        1,   152064, 0x0269f62d
+0,          3,          3,        1,   152064, 0x12168087
+0,          4,          4,        1,   152064, 0x42f9b5fb
+0,          5,          5,        1,   152064, 0xa653a8b3
+0,          6,          6,        1,   152064, 0x2e317bc3
+0,          7,          7,        1,   152064, 0xf3c28b63
+0,          8,          8,        1,   152064, 0x12e57fce
+0,          9,          9,        1,   152064, 0xeac238dd
+0,         10,         10,        1,   152064, 0x8fe74772
+0,         11,         11,        1,   152064, 0x982afc9c
+0,         12,         12,        1,   152064, 0xd82ead51
+0,         13,         13,        1,   152064, 0xf83ca211
+0,         14,         14,        1,   152064, 0xc01f8de2
+0,         15,         15,        1,   152064, 0x7ec60ec6
+0,         16,         16,        1,   152064, 0x1beb4dd3
+0,         17,         17,        1,   152064, 0x5a513899
+0,         18,         18,        1,   152064, 0x8c766a7b
+0,         19,         19,        1,   152064, 0x8bcddbb0
+0,         20,         20,        1,   152064, 0x01f6f558
+0,         21,         21,        1,   152064, 0xac7e240f
+0,         22,         22,        1,   152064, 0xe8811d38
+0,         23,         23,        1,   152064, 0x4ea268c9
+0,         24,         24,        1,   152064, 0xadc5f950
+0,         25,         25,        1,   152064, 0xdbf498fb
+0,         26,         26,        1,   152064, 0x1b999678
+0,         27,         27,        1,   152064, 0x085dd810
+0,         28,         28,        1,   152064, 0x4665a44f
+0,         29,         29,        1,   152064, 0x674764cf
+0,         30,         30,        1,   152064, 0x65e96a72
+0,         31,         31,        1,   152064, 0x44e0c539
+0,         32,         32,        1,   152064, 0xb124fc9e
+0,         33,         33,        1,   152064, 0x5cff79e3
+0,         34,         34,        1,   152064, 0x7dd94359
+0,         35,         35,        1,   152064, 0x3ec294b6
+0,         36,         36,        1,   152064, 0x675d3767
+0,         37,         37,        1,   152064, 0x9efa01cb
+0,         38,         38,        1,   152064, 0x321058d2
+0,         39,         39,        1,   152064, 0xe0d04e9c
+0,         40,         40,        1,   152064, 0xa4dd58d4
+0,         41,         41,        1,   152064, 0x4cc19dc5
+0,         42,         42,        1,   152064, 0x30a1bf77
+0,         43,         43,        1,   152064, 0x2c9d20f2
+0,         44,         44,        1,   152064, 0x55cb0447
+0,         45,         45,        1,   152064, 0x4daa7e4f
+0,         46,         46,        1,   152064, 0x2a4f53c7
+0,         47,         47,        1,   152064, 0x9fb8c583
+0,         48,         48,        1,   152064, 0x072eb401
+0,         49,         49,        1,   152064, 0xa203d8b7