diff --git a/floatimg.h b/floatimg.h
index 57c4a74..9d35c96 100644
--- a/floatimg.h
+++ b/floatimg.h
@@ -130,7 +130,7 @@ int fimg_mix_rgb_gray(FloatImg *img, float mix);
 int     fimg_shift_to_zero(FloatImg *s, FloatImg *d, float coefs[6]);
 
 /*	--> funcs/plasmas.c		*/
-int fimg_prototype_plasma(FloatImg *img, char *txt, int type);
+int fimg_prototype_plasma(FloatImg *img, double time, int type);
 
 /* * * * experimental ! */
 int fimg_classif_trial(FloatImg *src, FloatImg*dst, float fval, int notused);
diff --git a/funcs/Makefile b/funcs/Makefile
index 30825d0..8b29ebc 100644
--- a/funcs/Makefile
+++ b/funcs/Makefile
@@ -1,6 +1,6 @@
 #---------------------------------------------------------------
 
-COPT = -Wall -fpic -g -no-pie -DDEBUG_LEVEL=1
+COPT = -Wall -fpic -g -no-pie -DDEBUG_LEVEL=0
 DEPS = ../floatimg.h Makefile
 
 OBJS = fimg-png.o fimg-tiff.o misc-plots.o filtrage.o utils.o	\
@@ -29,7 +29,7 @@ tests.o:	tests.c tests.h $(DEPS)
 ../libfloatimg.a:       $(OBJS)
 	$(AR) r $@ $?
 
-displacement.o:	displacement.c
+displacement.o:	displacement.c  $(DEPS)
 	gcc $(COPT) -c $<
 
 fimg-png.o:		fimg-png.c $(DEPS)
diff --git a/funcs/fimg-png.c b/funcs/fimg-png.c
index 622eb6c..d494df7 100644
--- a/funcs/fimg-png.c
+++ b/funcs/fimg-png.c
@@ -170,7 +170,7 @@ unsigned char		*bytes, *bptr;
 double			maximum, fk;
 
 #if DEBUG_LEVEL
-fprintf(stderr, ">>> %-25s ( %p '%s' %x )\n", __func__, src, outname, flags);
+fprintf(stderr, ">>> %-25s ( %p '%s' 0x%x )\n", __func__, src, outname, flags);
 #endif
 
 /* convert ou floating datas to a byte/rgb array */
diff --git a/funcs/t.c b/funcs/t.c
index 3162cc2..18fe2ea 100644
--- a/funcs/t.c
+++ b/funcs/t.c
@@ -171,7 +171,7 @@ switch(opt) {
 		foo = essai_lecture_png(filename, outfile, 0);
 		break;
 	case Plasmas:
-		foo = essai_plasma(filename, outfile, 1, 13.37);
+		foo = essai_plasma(filename, outfile, 1, global_fvalue);
 		fprintf(stderr, "we are all plasmafields\n");
 		break;
 	default:
diff --git a/funcs/tests.c b/funcs/tests.c
index 430b67b..3d61ee4 100644
--- a/funcs/tests.c
+++ b/funcs/tests.c
@@ -17,6 +17,8 @@
 extern int		verbosity;
 
 /* --------------------------------------------------------------------- */
+/*
+ */
 int essai_plasma(char *infile, char *outfile, int ikoef, float fkoef)
 {
 FloatImg	src, dst;
@@ -27,15 +29,24 @@ fprintf(stderr, ">>> %s ( '%s' '%s' %d %g )\n", __func__,
 
 /* if infile is loadable, use it for background */
 foo = fimg_create_from_dump(infile, &src);
-if (foo) {
-	fprintf(stderr, "%s: error loading '%s'\n", __func__, infile);
-	return foo;
+if (0 == foo) {
+	fprintf(stderr, "%s: image '%s' loaded\n", __func__, infile);
+	}
+else	{
+	/* make a fancy synthetic picture */
+	foo = fimg_create(&src, 800, 600, FIMG_TYPE_RGB);
 	}
-fprintf(stderr, "'%s' loaded\n", infile);
-fimg_printhead(&src);
 
+fimg_printhead(&src);
 fimg_clone(&src, &dst, 1);
 
+foo = fimg_prototype_plasma(&dst, fkoef, 0);
+if (foo)  {
+	fprintf(stderr, "%s: err %d on plasma proto\n", __func__, foo);
+	return -88;
+	}
+
+fimg_mul_3(&src, &dst, &dst);
 
 foo = fimg_export_picture(&dst, outfile, 0);
 if (foo) {
diff --git a/funcs/vroum.sh b/funcs/vroum.sh
index f0039a4..5625b38 100755
--- a/funcs/vroum.sh
+++ b/funcs/vroum.sh
@@ -7,7 +7,7 @@ device=/dev/video2
 maxi=59
 W="320"
 H="240"
-grabopt=" -s ${W}x${H}w -vv -d $device -p 0 -n 30
+grabopt=" -s ${W}x${H} -vv -u -d $device -p 0 -n 30
 0 -c none "
 
 mkdir /tmp/V
@@ -22,10 +22,10 @@ do
 
 	grabvidseq -$grabopt -o $src
 
-	fval=$(echo "$foo / $maxi" | bc -l)
-	echo $foo ' => ' $fval
+	fval=$(echo "$foo / $maxi * 13.56636" | bc -l)
+	echo ; echo $foo ' => ' $fval
 
-	./t -vv -k $fval -o $out classif $src
+	./t -vv -k $fval -o $out plasma $src
 
 	# fimgstats $out
 
@@ -33,7 +33,7 @@ do
 	echo $dst
 	montage $src $out -tile 1x2 -geometry $G $dst
 
-	sleep 2
+	sleep 55
 
 done