diff --git a/.gitignore b/.gitignore
index 3cb5414..cb77163 100644
--- a/.gitignore
+++ b/.gitignore
@@ -70,6 +70,7 @@ Fonderie/*.gif
 Fonderie/fonderie
 Fonderie/interpolator
 Fonderie/t
+Fonderie/singlepass
 Fonderie/crapdef.h
 Fonderie/crapstr.h
 
diff --git a/Fonderie/README.md b/Fonderie/README.md
index cc7ee24..7d8aa43 100644
--- a/Fonderie/README.md
+++ b/Fonderie/README.md
@@ -99,6 +99,19 @@ Un logiciel dont l'inspiration vient du passé et les améliorations
 d'une résidence à Terre-Blanque, ça ne peut pas être complètement
 malsain.
 
+```
+*** interpolator.c : compiled by tTh, Jan 12 2021 16:18:58
+*** FloatImg library, alpha v116 (Dec 27 2020, 22:39:28)
+        INTERPOLATOR
+usage:
+        interpolator [options] <inglob> <outdir> <nbsteep>
+options:
+        -S nn           mysterious sort
+        -E i:bla:k      input  filter chain
+        -F name:j       output filter chain
+        -L              list available filters
+        -v              increase verbosity
+```
 
 
 ## Conclusion
diff --git a/Fonderie/crapulator.c b/Fonderie/crapulator.c
index 81fabf3..28d525f 100644
--- a/Fonderie/crapulator.c
+++ b/Fonderie/crapulator.c
@@ -22,7 +22,7 @@ int		foo;
 
 fimg_clone(pimg, &copy, 1);
 
-foo = fimg_qsort_rgb_b(pimg, &copy, 0);
+foo = fimg_qsort_rgb_a(pimg, &copy, 0);
 if (foo) {
 	fprintf(stderr, "%s: err qsort rgb = %d\n", __func__, foo);
 	return foo;
@@ -209,7 +209,7 @@ switch (idFx) {
 						image->height/20);
 		break;
 	case CR_water:
-		retval = bouger_les_pixels(image, 8);
+		retval = bouger_les_pixels(image, 12);
 		break;
 	case CR_mirsplit:
 		retval = mirror_split(image, 0);
diff --git a/Fonderie/essai.sh b/Fonderie/essai.sh
index 56379b6..0bbe3e3 100755
--- a/Fonderie/essai.sh
+++ b/Fonderie/essai.sh
@@ -28,24 +28,24 @@ echo ; echo "making gif89a..."
 convert -delay 200 /tmp/fstack*.png foo.gif
 }
 # ------------------------------------------------------------
-essai_single ()
+essai_singlepass ()
 {
 MP4="/home/tth/Essais/FondageDePlomb/foo.mp4"
-INPUT="/home/tth/Essais/FondageDePlomb/capture/?[23]???.fimg"
-FILTRE="classtrial:liss3x3"
+INPUT="/home/tth/Essais/FondageDePlomb/capture/???[04]0.fimg"
+FILTRE="water:water:liss3x3"
+OUTDIR="/tmp/x8/"
 
 echo '********* essai single *********'
 
+rm $OUTDIR/*.png
 
-rm /tmp/x8/*.png
+time ./singlepass -v -g "$INPUT" -F $FILTRE -O $OUTDIR -s
 
-time ./t -v -g "$INPUT" -F $FILTRE -s
-
-echo ; echo "encoding to " $MP4
+echo ; echo "encoding picz to " $MP4
 
 ffmpeg	-nostdin				\
 	-loglevel error					\
-	-y -r 30 -f image2 -i /tmp/x8/%05d.png	 	\
+	-y -r 25 -f image2 -i /tmp/x8/%05d.png	 	\
 	-c:v libx264 -pix_fmt yuv420p			\
 	$MP4
 
@@ -53,6 +53,6 @@ ffmpeg	-nostdin				\
 # ------------------------------------------------------------
 #			MAIN
 
-essai_single
+essai_singlepass
 
 # ------------------------------------------------------------
diff --git a/Fonderie/filterstack.c b/Fonderie/filterstack.c
index 526f754..f92322e 100644
--- a/Fonderie/filterstack.c
+++ b/Fonderie/filterstack.c
@@ -233,7 +233,7 @@ for (;;) {
 		}
 	}
 
-if (verbosity) filterstack_list(numid, __func__);
+if (verbosity > 1) filterstack_list(numid, __func__);
 return 0;
 }
 /* ----------------------------------------------------------- */
diff --git a/Fonderie/fonctions.c b/Fonderie/fonctions.c
index 01a04f6..c2b394f 100644
--- a/Fonderie/fonctions.c
+++ b/Fonderie/fonctions.c
@@ -79,14 +79,6 @@ int		foo, type;
 
 foo = faire_la_somme(&g_fifo, NULL, step);
 
-/* BEGIN GRUIK CODE */
-extern int	convert_to_gray;
-/* END OF THE KLUGE */
-if (convert_to_gray) {
-	fimg_to_gray(&g_fifo.total);
-	// fprintf(stderr, "%p gray-washed\n", &fifo.total);
-	}
-
 if (postproc)
 	foo = crapulator(&g_fifo.total, postproc, 0.0);
 else
diff --git a/Fonderie/fonderie.c b/Fonderie/fonderie.c
index 8d0e8e8..4abe836 100644
--- a/Fonderie/fonderie.c
+++ b/Fonderie/fonderie.c
@@ -15,7 +15,6 @@
 #include  "filterstack.h"
 
 int			verbosity;
-int			convert_to_gray;
 
 /* -------------------------------------------------------------- */
 int traite_une_image(FloatImg *image, int proc, int step, char *outd)
@@ -168,7 +167,7 @@ puts("\tFONDERIE\noptions:");
 
 puts("\t-E\tinput:filter:chain");
 puts("\t-F\toutput:filter:chain");
-puts("\t-g\tconvert to gray");
+// puts("\t-g\tconvert to gray");
 puts("\t-I\tinput glob pattern");
 puts("\t-L\tlist available filters");
 puts("\t-O\toutput directory");
@@ -201,7 +200,7 @@ while ((opt = getopt(argc, argv, "B:E:F:ghI:LO:s:T:vw:x:")) != -1) {
 		case 'F':	OutFchain = optarg;		break;
 		case 'B':	blanks = atoi(optarg);
 				break;
-		case 'g':	convert_to_gray = 1;
+		case 'g':	// convert_to_gray = 1;
 				break;
 		case 'h':	help();	
 				break;
diff --git a/Fonderie/interpolator.c b/Fonderie/interpolator.c
index 9f3ea88..d38ba67 100644
--- a/Fonderie/interpolator.c
+++ b/Fonderie/interpolator.c
@@ -23,7 +23,6 @@
 #include  "filterstack.h"
 
 int		verbosity;
-int		convert_to_gray;	/* needed by fonctions.c */
 
 /* -------------------------------------------------------------- */
 /*  on va essayer de trier l'ordre d'apparition des images
diff --git a/Fonderie/sfx.c b/Fonderie/sfx.c
index 902841b..8d4b920 100644
--- a/Fonderie/sfx.c
+++ b/Fonderie/sfx.c
@@ -242,6 +242,7 @@ for (x=0; x<pimg->width; x++) {
                               || ny>=pimg->height )
 					continue;
 
+		/* XXX optimize here ? */
 	    fimg_get_rgb(pimg, nx, ny, rgb);
 	    fimg_put_rgb(pimg,  x,  y, rgb);
 
diff --git a/Fonderie/single.c b/Fonderie/single.c
index f400e53..fea6f48 100644
--- a/Fonderie/single.c
+++ b/Fonderie/single.c
@@ -31,7 +31,10 @@ int single_init(int next, char *dest, int fxchain)
 int			foo;
 struct stat		stbuf;
 
-fprintf(stderr, ">>> %s ( %d '%s' )\n", __func__, next, dest);
+#if DEBUG_LEVEL
+fprintf(stderr, ">>> %s ( %d '%s' %d )\n", __func__,
+			next, dest, fxchain);
+#endif
 
 nextpng = next;
 chainfilter = fxchain;
@@ -95,6 +98,10 @@ fprintf(stderr, "   chainfilter      %d\n", chainfilter);
 
 fprintf(stderr, "   destination      %s\n", destination);
 
+if (k) {
+
+	}
+
 return -1;
 }
 /* -------------------------------------------------------------- */
diff --git a/Fonderie/singlepass.c b/Fonderie/singlepass.c
index 2152a7f..5a2ebd4 100644
--- a/Fonderie/singlepass.c
+++ b/Fonderie/singlepass.c
@@ -7,17 +7,101 @@
 #include  <stdio.h>
 #include  <stdlib.h>
 #include  <unistd.h>
+#include  <string.h>
+#include  <glob.h>
 
 #include  "../floatimg.h"
 
+#include  "crapulator.h"
+#include  "filterstack.h"
 #include  "single.h"
 
 /* ----------------------------------------------------------- */
 
+#define   FILTERS	0
+
 int		verbosity;
 
 /* ----------------------------------------------------------- */
+int run_the_singlepass(char *globber, char *destdir, int fchain)
+{
+FloatImg	image = { 0 };
+int		idx, foo;
+glob_t		globbuf;
+char		*fname;
 
+#if DEBUG_LEVEL
+fprintf(stderr, ">>> %s ( '%s' '%s' %d )\n", __func__,
+				globber, destdir, fchain);
+#endif
+
+// filterstack_list(fchain, "Run the single pass");
+
+foo = single_init(0, destdir, fchain);
+if (foo) {
+	fprintf(stderr, "erreur %d single_init\n", foo);
+	return foo;
+	}
+// single_print_state("just after init", 0);
+
+memset(&globbuf, 0, sizeof(glob_t));
+foo = glob(globber, 0, NULL, &globbuf);
+// fprintf(stderr, "globbing '%s' -> %d, %d files found\n",
+//			globber, foo, (int)globbuf.gl_pathc);
+switch (foo) {
+	case GLOB_NOSPACE:
+		fprintf(stderr, "%s: glob run out of memory\n", __func__);
+		break;
+	case GLOB_ABORTED:
+		fprintf(stderr, "%s: glob read error\n", __func__);
+		break;
+	case GLOB_NOMATCH:
+		fprintf(stderr, "%s: glob found no matches\n", __func__);
+		break;
+	}
+
+if (0 == globbuf.gl_pathc) {
+	fprintf(stderr, "%s: no file found, aborting\n", __func__);
+	return -1;
+	}
+
+for (idx=0; idx<globbuf.gl_pathc; idx++) {
+
+	fname = globbuf.gl_pathv[idx];		/* alias of filename */
+	fprintf(stderr, "  %6d  %s\r", globbuf.gl_pathc-idx, fname);
+
+	if (0==image.width && 0==image.height) {
+		foo = fimg_create_from_dump(fname, &image);
+		}
+	else	{
+		foo = fimg_load_from_dump(fname, &image);
+		}
+	if (foo) {
+		fprintf(stderr, "get image -> %d\n", foo);
+		return -1;
+		}
+
+	foo = filterstack_run(fchain, &image, 0);
+	if (foo) {
+		fprintf(stderr, "%s: filterstack run --> %d\n",
+				__func__,                 foo);
+		return foo;
+		}
+
+	foo = single_push_picture(&image);
+	if (foo) {
+		fprintf(stderr, "error %d on push_picture\n", foo);
+		return foo;
+		}
+	}
+
+fprintf(stderr, "\n");
+single_print_state("end of run :)", 0);
+
+fimg_destroy(&image);
+
+return -1;
+}
 /* ----------------------------------------------------------- */
 static void help(void)
 {
@@ -39,7 +123,7 @@ int main(int argc, char *argv[])
 int		foo, opt;
 char		*filterchain =   "none";
 char		*globbing    =   "./capture/?????.fimg";
-char		*outdir      =   "./png/";
+char		*outdir      =   "./p8";
 int		do_xper = 0;
 
 fprintf(stderr, "*** %s : compiled %s %s\n", __FILE__,
@@ -67,6 +151,15 @@ while ((opt = getopt(argc, argv, "hF:g:LO:svx")) != -1) {
 
 	}
 
+foo = parse_filter_chain(FILTERS, filterchain);
+if (foo) {
+	fprintf(stderr, "err %d in parse_filter_chain\n", foo);
+	exit(1);
+	}
+
+foo = run_the_singlepass(globbing, outdir, FILTERS);
+fprintf(stderr, "\n\tRun the single pass --> %d\n", foo);
+
 return 0;
 }
 
diff --git a/Fonderie/t.c b/Fonderie/t.c
index 951db68..450fe25 100644
--- a/Fonderie/t.c
+++ b/Fonderie/t.c
@@ -18,7 +18,6 @@
 /* ----------------------------------------------------------- */
 
 int		verbosity;
-int		convert_to_gray;	/* WTF ? */
 
 #define		PNG	"out.png"
 #define		W	800
@@ -83,9 +82,10 @@ int		idx, foo;
 glob_t		globbuf;
 char		*fname;
 
+#if DEBUG_LEVEL
 fprintf(stderr, ">>> %s ( '%s' '%s' %d )\n", __func__,
 			globpattern, destdir, chain);
-
+#endif
 
 filterstack_list(chain, "essai du single");
 
@@ -137,11 +137,11 @@ for (idx=0; idx<globbuf.gl_pathc; idx++) {
 
 fprintf(stderr, "\n");
 
-single_print_state("end of run", 0);
+single_print_state("end of run :)", 0);
 
 fimg_destroy(&image);
 
-return -1;
+return 0;
 }
 /* ----------------------------------------------------------- */