fate/filter: move concat filtergraph to a dedicated script.

tests/fate/filter.mak

@@ -116,7 +116,7 @@ FATE_FILTER-$(call ALLYES, VMD_DEMUXER VMDVIDEO_DECODER FORMAT_FILTER PERMS_FILT
 fate-filter-gradfun-sample: CMD = framecrc -i $(SAMPLES)/vmd/12.vmd -vf "sws_flags=+accurate_rnd+bitexact;format=gray,perms=random,gradfun=10:8" -an -frames:v 20
 
 FATE_FILTER-$(call ALLYES, TESTSRC_FILTER SINE_FILTER CONCAT_FILTER) += fate-filter-concat
-fate-filter-concat: CMD = framecrc -lavfi "testsrc=r=5:n=1:d=2[v1];sine=440:b=2:d=1[a1];testsrc=r=5:n=1:d=1[v2];sine=622:b=2:d=2[a2];testsrc=r=5:n=1:d=1[v3];sine=880:b=2:d=1[a3];[v1][a1][v2][a2][v3][a3]concat=v=1:a=1:n=3"
+fate-filter-concat: CMD = framecrc -filter_complex_script $(SRC_PATH)/tests/filtergraphs/concat
 
 $(FATE_FILTER_VSYNTH-yes): tests/vsynth1/00.pgm
 $(FATE_FILTER_VSYNTH-yes): SRC = $(TARGET_PATH)/tests/vsynth1/%02d.pgm

tests/filtergraphs/concat

+testsrc=r=5:n=1:d=2 [v1];
+sine=440:b=2:d=1    [a1];
+testsrc=r=5:n=1:d=1 [v2];
+sine=622:b=2:d=2    [a2];
+testsrc=r=5:n=1:d=1 [v3];
+sine=880:b=2:d=1    [a3];
+
+[v1][a1][v2][a2][v3][a3] concat=v=1:a=1:n=3