diff --git a/v4l2/Makefile b/v4l2/Makefile
index fe6c561..ace84c9 100644
--- a/v4l2/Makefile
+++ b/v4l2/Makefile
@@ -1,6 +1,6 @@
 
 
-COPT = -Wall -fpic -g -no-pie -DDEBUG_LEVEL=1
+COPT = -Wall -fpic -g -pg -no-pie -DDEBUG_LEVEL=1
 DEPS = ../floatimg.h  ../libfloatimg.a Makefile
 
 all:	grabvidseq t
diff --git a/v4l2/funcs.h b/v4l2/funcs.h
index 86c1154..a4c28c8 100644
--- a/v4l2/funcs.h
+++ b/v4l2/funcs.h
@@ -8,6 +8,8 @@ int init_device(int notused);
 
 /* --------------------------------------------------------------------- */
 
+int x_upscaler_0(unsigned char *src, int w, int h, FloatImg *d);
+
 int x_add_rgb2fimg(unsigned char *src, int w, int h, FloatImg *d);
 
 int x_rgb2fimg(unsigned char *src, int w, int h, FloatImg *d);
diff --git a/v4l2/grabvidseq.c b/v4l2/grabvidseq.c
index a15fc5e..0e895b6 100644
--- a/v4l2/grabvidseq.c
+++ b/v4l2/grabvidseq.c
@@ -75,8 +75,9 @@ puts("\t-g\t\tconvert to gray");
 puts("\t-n NNN\t\thow many frames ?");
 puts("\t-O ./\t\tset Output dir");
 puts("\t-o bla\t\tset output filename");
-puts("\t-p NNN\t\tperiod in seconds");
+puts("\t-p NN.N\t\tperiod in seconds");
 puts("\t-s WxH\t\tsize of capture");
+puts("\t-u\t\ttry upscaling...");
 puts("\t-v\t\tincrease verbosity");
 exit(0);
 }
@@ -105,14 +106,15 @@ int		width = 640;
 int		height = 480;
 double		t_final;
 int		to_gray = 0;
+int		upscaling = 0;
 char		*dest_dir = ".";	/* no trailing slash */
 char		*outfile = "out.pnm";
 
 #if SAVE_AS_CUMUL
-FloatImg	grab, cumul;
+FloatImg	cumul;
 #endif
 
-while ((opt = getopt(argc, argv, "d:ghn:o:O:p:s:v")) != -1) {
+while ((opt = getopt(argc, argv, "d:ghn:o:O:p:s:uv")) != -1) {
 	switch(opt) {
 		case 'd':	dev_name = optarg;		break;
 		case 'g':	to_gray = 1;			break;
@@ -121,7 +123,9 @@ while ((opt = getopt(argc, argv, "d:ghn:o:O:p:s:v")) != -1) {
 		case 'O':	dest_dir = optarg;		break;
 		case 'o':	outfile = optarg;		break;
 		case 'p':	period = 1e6*atof(optarg);	break;
-		case 's':	parse_WxH(optarg, &width, &height);	break;
+		case 's':	parse_WxH(optarg, &width, &height);
+				break;
+		case 'u':	upscaling = 1;			break;
 		case 'v':	verbosity++;			break;
 		}
 	}
@@ -193,12 +197,17 @@ for (i = 0; i < n_buffers; ++i) {
 	}
 
 #if SAVE_AS_CUMUL
-foo = fimg_create(&grab,
-		fmt.fmt.pix.width, fmt.fmt.pix.height,
-		FIMG_TYPE_RGB);
-foo = fimg_create(&cumul,
-		fmt.fmt.pix.width, fmt.fmt.pix.height,
-		FIMG_TYPE_RGB);
+if (upscaling) {
+	foo = fimg_create(&cumul,
+			fmt.fmt.pix.width*2, fmt.fmt.pix.height*2,
+			FIMG_TYPE_RGB);
+	}
+else	{
+	foo = fimg_create(&cumul,
+			fmt.fmt.pix.width, fmt.fmt.pix.height,
+			FIMG_TYPE_RGB);
+	}
+
 fimg_clear(&cumul);
 cumul.fval = 255.0;
 cumul.count = 0;
@@ -256,13 +265,14 @@ for (i = 0; i < nbre_capt; i++) {
 #endif
 
 #if SAVE_AS_CUMUL
-	/** this is the slow version
-	x_rgb2fimg(buffers[buf.index].start,
-		fmt.fmt.pix.width, fmt.fmt.pix.height, &grab);
-	fimg_add(&grab, &cumul, &cumul);
-	**/
-	x_add_rgb2fimg(buffers[buf.index].start,
-		fmt.fmt.pix.width, fmt.fmt.pix.height, &cumul);
+	if (upscaling) {
+		x_upscaler_0(buffers[buf.index].start,
+			fmt.fmt.pix.width, fmt.fmt.pix.height, &cumul);
+		}
+	else	{
+		x_add_rgb2fimg(buffers[buf.index].start,
+			fmt.fmt.pix.width, fmt.fmt.pix.height, &cumul);
+		}
 #endif
 
 #if SAVE_AS_FIMG
@@ -281,18 +291,19 @@ for (i = 0; i < nbre_capt; i++) {
 }
 
 t_final = fimg_timer_get(0);
-fprintf(stderr, "pid %d : elapsed time %g s\n", getpid(), t_final);
-fprintf(stderr, "\t%.2f fps\n", (double)nbre_capt / t_final);
+fprintf(stderr, "pid %d : elapsed %g s -> %.2f fps\n", getpid(),
+			t_final, (double)nbre_capt / t_final);
 
 #if SAVE_AS_CUMUL
 if (to_gray) {
 	if (verbosity)	fputs("converting to gray\n", stderr);
 	foo = fimg_to_gray(&cumul);
 	}
+
 	// save cumul to file
 foo = fimg_save_as_pnm(&cumul, outfile, 0);
+
 	// free buffers
-fimg_destroy(&grab);
 fimg_destroy(&cumul);
 #endif
 
diff --git a/v4l2/rgb2fimg.c b/v4l2/rgb2fimg.c
index 07e7bf2..7cd6ba8 100644
--- a/v4l2/rgb2fimg.c
+++ b/v4l2/rgb2fimg.c
@@ -5,15 +5,17 @@
 
 #include  "funcs.h"
 
+extern	int	verbosity;
+
 /*
  *		Be careful, these functions are not yet fireproof,
  *		and calling conventions are fluctuating.
  */
 
 /* --------------------------------------------------------------------- */
-int x_upscaler(unsigned char *src, int w, int h, FloatImg *d)
+int x_upscaler_0(unsigned char *src, int w, int h, FloatImg *d)
 {
-int				x, y, xx, yy;
+int				x, y, xx, yy, ox, oy;
 // float				*rp, *gp, *bp;
 float				r, g, b;
 static unsigned short		modz;
@@ -26,12 +28,16 @@ if ( d->width != w*2 || d->height != h*2 ) {
 	return -2;
 	}
 
-// rp = d->R, gp = d->G, bp = d->B;
+ox = ! (modz & 2);
+oy = ! (modz & 1);
+
+if (verbosity>2)	fprintf(stderr, "%s   %5d  %d %d\n", __func__,
+					modz, ox, oy);
 
 for (y=0; y<h; y++) {
-	yy = (y*2) + ! (modz & 1);
+	yy = (y*2) + oy;
 	for (x=0; x<w; x++) {
-		xx = (x*2) + ! (modz & 2);
+		xx = (x*2) + ox;
 		r = (float)*src++;
 		g = (float)*src++;
 		b = (float)*src++;