diff --git a/configure.ac b/configure.ac
index f3691be..f6540c2 100644
--- a/configure.ac
+++ b/configure.ac
@@ -439,6 +439,9 @@ AC_ARG_ENABLE(gconv,
    esac]
 )
 
+PKG_CHECK_MODULES([SDL2], [sdl2 SDL2_image], [sdl_pc=yes], [sdl_pc=no])
+AM_CONDITIONAL([HAVE_SDL], [test x$sdl_pc = xyes])
+
 # Check if backtrace functions are defined
 AC_SEARCH_LIBS([backtrace], [execinfo], [
   AC_DEFINE(HAVE_BACKTRACE, [1], [glibc has functions to provide stack backtrace])
@@ -507,6 +510,7 @@ compile time options summary
     pthread                    : $have_pthread
     QT version                 : $QT_VERSION
     ALSA support               : $USE_ALSA
+    SDL support		       : $sdl_pc
 
     build dynamic libs         : $enable_shared
     build static libs          : $enable_static
diff --git a/contrib/test/Makefile.am b/contrib/test/Makefile.am
index 4641e21..0f97ce2 100644
--- a/contrib/test/Makefile.am
+++ b/contrib/test/Makefile.am
@@ -16,6 +16,10 @@ if HAVE_GLU
 noinst_PROGRAMS += v4l2gl
 endif
 
+if HAVE_SDL
+noinst_PROGRAMS += sdlcam
+endif
+
 driver_test_SOURCES = driver-test.c
 driver_test_LDADD = ../../utils/libv4l2util/libv4l2util.la
 
@@ -31,6 +35,10 @@ v4l2gl_SOURCES = v4l2gl.c
 v4l2gl_LDFLAGS = $(X11_LIBS) $(GL_LIBS) $(GLU_LIBS) $(ARGP_LIBS)
 v4l2gl_LDADD = ../../lib/libv4l2/libv4l2.la ../../lib/libv4lconvert/libv4lconvert.la
 
+sdlcam_LDFLAGS = $(JPEG_LIBS) $(SDL2_LIBS)
+sdlcam_CFLAGS = -I../.. $(SDL2_CFLAGS)
+sdlcam_LDADD = ../../lib/libv4l2/.libs/libv4l2.a  ../../lib/libv4lconvert/.libs/libv4lconvert.a
+
 mc_nextgen_test_CFLAGS = $(LIBUDEV_CFLAGS)
 mc_nextgen_test_LDFLAGS = $(LIBUDEV_LIBS)
 
diff --git a/contrib/test/sdlcam.c b/contrib/test/sdlcam.c
new file mode 100644
index 0000000..cc43a10
--- /dev/null
+++ b/contrib/test/sdlcam.c
@@ -0,0 +1,1250 @@
+/*
+   Digital still camera.
+
+   SDL based, suitable for camera phone such as Nokia N900. In
+   particular, we support focus, gain and exposure control, but not
+   aperture control or lens zoom.
+
+   Copyright 2017 Pavel Machek, LGPL
+
+   Needs sdl2, sdl2_image libraries. sudo aptitude install libsdl2-dev
+   libsdl2-image-dev on Debian systems.
+*/
+
+#include <time.h>
+#include <errno.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/time.h>
+#include <sys/ioctl.h>
+#include <fcntl.h>
+
+#include <jpeglib.h>
+
+#include "libv4l2.h"
+#include <linux/videodev2.h>
+#include "libv4l-plugin.h"
+
+#include <SDL2/SDL.h>
+#include <SDL2/SDL_image.h>
+
+#define PICDIR "."
+#define SX 2592
+#define SY 1968
+#define SIZE SX*SY*3
+
+static void fmt_print(struct v4l2_format *fmt)
+{
+	int f;
+	printf("Format: %dx%d. ", fmt->fmt.pix.width, fmt->fmt.pix.height);
+	printf("%x ", fmt->fmt.pix.pixelformat);
+	f = fmt->fmt.pix.pixelformat;
+	for (int i=0; i<4; i++) {
+		printf("%c", f & 0xff);
+		f >>= 8;
+	}
+	printf("\n");
+}
+
+static double dtime(void)
+{
+	static double start = 0.0;
+	struct timeval now;
+
+	gettimeofday(&now, NULL);
+
+	double n = now.tv_sec + now.tv_usec / 1000000.;
+	if (!start)
+		start = n;
+	return n - start;
+}
+
+static long v4l2_g_ctrl(int fd, long id)
+{
+	int res;
+	struct v4l2_control ctrl;
+	ctrl.id = id;
+	ctrl.value = 0;
+	res = v4l2_ioctl(fd, VIDIOC_G_CTRL, &ctrl);
+	if (res < 0)
+		printf("Get control %lx failed\n", id);
+	return ctrl.value;
+}
+
+static int v4l2_s_ctrl(int fd, long id, long value)
+{
+	int res;
+	struct v4l2_control ctrl;
+	ctrl.id = id;
+	ctrl.value = value;
+	res = v4l2_ioctl(fd, VIDIOC_S_CTRL, &ctrl);
+	if (res < 0)
+		printf("Set control %lx %ld failed\n", id, value);
+	return res;
+}
+
+static int v4l2_set_focus(int fd, int diopt)
+{
+	if (v4l2_s_ctrl(fd, V4L2_CID_FOCUS_ABSOLUTE, diopt) < 0) {
+		printf("Could not set focus\n");
+	}
+	return 0;
+}
+
+struct dev_info {
+	int fd;
+	struct v4l2_format fmt;
+
+	unsigned char buf[SIZE];
+	int debug;
+#define D_TIMING 1
+};
+
+struct sdl {
+	SDL_Window *window;
+	SDL_Surface *screen, *liveview;
+
+	int wx, wy; /* Window size */
+	int sx, sy; /* Live view size */
+	int bx, by; /* Border size */
+	int nx, ny; /* Number of buttons */
+	float factor;
+
+	/* These should go separately */
+	int do_focus, do_exposure, do_flash, do_white, do_big, do_full;
+	double zoom;
+	double focus_min;
+
+	int slider_mode;
+#define M_BIAS 0
+#define M_EXPOSURE 1
+#define M_GAIN 2
+#define M_FOCUS 3
+#define M_NUM 4
+
+	int fd;
+
+	struct dev_info *dev;
+};
+
+typedef struct {
+	uint8_t r, g, b, alpha;
+} pixel;
+
+#define d_raw 1
+
+static void sfc_put_pixel(SDL_Surface* liveview, int x, int y, pixel *p)
+{
+	Uint32* p_liveview = (Uint32*)liveview->pixels;
+	p_liveview += y*liveview->w+x;
+	*p_liveview = SDL_MapRGBA(liveview->format, p->r, p->g, p->b, p->alpha);
+}
+
+static void sdl_begin_paint(struct sdl *m)
+{
+	/* Fill the surface white */
+	SDL_FillRect(m->liveview, NULL, SDL_MapRGB( m->liveview->format, 0, 0, 0 ));
+
+	SDL_LockSurface(m->liveview);
+}
+
+static void sdl_finish_paint(struct sdl *m) {
+	SDL_UnlockSurface(m->liveview);
+	SDL_Rect rcDest = { m->bx, m->by, m->sx, m->sy };
+
+	SDL_BlitSurface(m->liveview, NULL, m->screen, &rcDest);
+	SDL_UpdateWindowSurfaceRects(m->window, &rcDest, 1);
+}
+
+static void sdl_paint_image(struct sdl *m, char **xpm, int x, int y) {
+	SDL_Surface *image = IMG_ReadXPMFromArray(xpm);
+	if (!image) {
+		printf("IMG_Load: %s\n", IMG_GetError());
+		exit(1);
+	}
+
+	int x_pos = x - image->w/2, y_pos = y - image->h/2;
+
+	SDL_Rect rcDest = { x_pos, y_pos, image->w, image->h };
+	int r = SDL_BlitSurface(image, NULL, m->screen, &rcDest);
+
+	if (r) {
+		printf("Error blitting: %s\n", SDL_GetError());
+		exit(1);
+	}
+	SDL_FreeSurface(image);
+}
+
+static void cam_exposure_limits(struct sdl *m, struct v4l2_queryctrl *qctrl)
+{
+	qctrl->id = V4L2_CID_EXPOSURE_ABSOLUTE;
+
+	if (v4l2_ioctl(m->fd, VIDIOC_QUERYCTRL, qctrl)) {
+		printf("Exposure absolute limits failed\n");
+		exit(1);
+	}
+
+	/* Minimum of 11300 gets approximately same range on ISO and
+	 * exposure axis. */
+	if (qctrl->minimum < 500)
+		qctrl->minimum = 500;
+}
+
+static void cam_set_exposure(struct sdl *m, double v)
+{
+	int cid = V4L2_CID_EXPOSURE_ABSOLUTE;
+	double res;
+	double range;
+	struct v4l2_queryctrl qctrl = { .id = cid };
+	struct v4l2_control ctrl = { .id = cid };
+
+	cam_exposure_limits(m, &qctrl);
+
+	if (v4l2_ioctl(m->fd, VIDIOC_G_CTRL, &ctrl)) {
+		printf("Can't get exposure parameters\n");
+		exit(1);
+	}
+
+	range = log2(qctrl.maximum) - log2(qctrl.minimum);
+	res = log2(qctrl.minimum) + v*range;
+	res = exp2(res);
+
+	v4l2_s_ctrl(m->fd, V4L2_CID_EXPOSURE_ABSOLUTE, res);
+}
+
+static double cam_convert_exposure(struct sdl *m, int v)
+{
+	int cid = V4L2_CID_EXPOSURE_ABSOLUTE;
+	double res;
+	struct v4l2_queryctrl qctrl = { .id = cid };
+
+	cam_exposure_limits(m, &qctrl);
+	res = (log2(v) - log2(qctrl.minimum)) / (log2(qctrl.maximum) - log2(qctrl.minimum));
+
+	return res;
+}
+
+static double cam_get_exposure(struct sdl *m)
+{
+	int cid = V4L2_CID_EXPOSURE_ABSOLUTE;
+	struct v4l2_control ctrl = { .id = cid };
+
+	if (v4l2_ioctl(m->fd, VIDIOC_G_CTRL, &ctrl))
+		return -1;
+
+	return cam_convert_exposure(m, ctrl.value);
+}
+
+static int cam_get_gain_iso(struct dev_info *dev)
+{
+	double x;
+
+	x = v4l2_g_ctrl(dev->fd, 0x00980913);
+	x = (x / 10); /* EV */
+	x = exp2(x);
+	x = 100*x;
+	return x;
+}
+
+static void cam_set_focus(struct sdl *m, double val)
+{
+	v4l2_s_ctrl(m->fd, V4L2_CID_FOCUS_ABSOLUTE, (val * m->focus_min) * (1023. / 20));
+}
+
+static double cam_convert_focus(struct sdl *m, double diopter)
+{
+	return diopter / m->focus_min;
+}
+
+static double cam_get_focus_diopter(struct sdl *m)
+{
+	return (v4l2_g_ctrl(m->fd, V4L2_CID_FOCUS_ABSOLUTE) * 20.) / 1023.;
+}
+
+static double cam_get_focus(struct sdl *m)
+{
+	return cam_convert_focus(m, cam_get_focus_diopter(m));
+}
+
+static void sdl_line_color(struct sdl *m, int x1, int y1, int x2, int y2, Uint32 color)
+{
+	SDL_Rect rcDest = { x1, y1, x2-x1+1, y2-y1+1};
+
+	SDL_FillRect(m->screen, &rcDest, color);
+}
+
+static void sdl_line(struct sdl *m, int x1, int y1, int x2, int y2)
+{
+	sdl_line_color(m, x1, y1, x2, y2, SDL_MapRGB( m->liveview->format, 255, 255, 255 ));
+}
+
+static void sdl_digit(struct sdl *m, int x, int y, int s, int i)
+{
+	unsigned char gr[] = { 0x5f, 0x0a, 0x76, 0x7a, 0x2b,
+			       0x79, 0x7d, 0x1a, 0x7f, 0x7b };
+	unsigned char g = gr[i];
+	/*
+              10
+	    01  02
+              20
+            04  08
+	      40
+	*/
+
+	if (g & 1) sdl_line(m, x, y, x, y+s);
+	if (g & 2) sdl_line(m, x+s, y, x+s, y+s);
+	if (g & 4) sdl_line(m, x, y+s, x, y+s+s);
+	if (g & 8) sdl_line(m, x+s, y+s, x+s, y+s+s);
+
+	if (g & 0x10) sdl_line(m, x, y, x+s, y);
+	if (g & 0x20) sdl_line(m, x, y+s, x+s, y+s);
+	if (g & 0x40) sdl_line(m, x, y+s+s, x+s, y+s+s);
+}
+
+static void sdl_number(struct sdl *m, int x, int y, int s, int digits, int i)
+{
+	int tot = s * 5;
+	x += tot * digits;
+	for (int j=0; j<digits; j++) {
+		sdl_digit(m, x+2, y+4, s*3, i%10);
+		i /= 10;
+		x -= tot;
+	}
+}
+
+static void sdl_icon_pos(struct sdl *m, int *x, int *y, double val)
+{
+	*x = m->wx - 10;
+	*y = val * m->wy;
+}
+
+static void sdl_paint_ui_iso(struct sdl *m, double y_, int i)
+{
+	static char *iso_xpm[] = {
+		"16 12 2 1",
+		"x c #ffffff",
+		". c #000000",
+		"................",
+		"................",
+		"................",
+		".x..xx..x.......",
+		".x.x...x.x......",
+		".x..x..x.x......",
+		".x...x.x.x......",
+		".x.xx...x.......",
+		"................",
+		"................",
+		"................",
+		"................",
+	};
+
+	int x, y;
+
+	sdl_icon_pos(m, &x, &y, y_);
+	sdl_number(m, x-35, y-10, 1, 3, i);
+	sdl_paint_image(m, iso_xpm, x, y);
+}
+
+static void sdl_paint_ui_exposure(struct sdl *m, int t)
+{
+	static char *time_1_xpm[] = {
+		"16 12 2 1",
+		"x c #ffffff",
+		". c #000000",
+		"......x.........",
+		".....x..........",
+		"....x...........",
+		"...x............",
+		"................",
+		".xxx.xxxx.xxxx..",
+		"x....x....x.....",
+		".xx..xxx..x.....",
+		"...x.x....x.....",
+		"...x.x....x.....",
+		"xxx..xxxx.xxxx..",
+		"................",
+	};
+	int x, y;
+
+	sdl_icon_pos(m, &x, &y, cam_convert_exposure(m, 1000000/t));
+	sdl_number(m, x-35, y-10, 1, 3, t);
+	sdl_paint_image(m, time_1_xpm, x, y);
+}
+
+static void sdl_paint_boolean(struct sdl *m, char **image, int x, int y, int yes)
+{
+	static char *not_xpm[] = {
+		"16 12 2 1",
+		"x c #ffffff",
+		". c #000000",
+		"......xxxxx.....",
+		"....xx.....xx...",
+		"...x.........x..",
+		"..x........xx.x.",
+		"..x......xx...x.",
+		".x.....xx......x",
+		".x...xx........x",
+		"..xxx.........x.",
+		"..x...........x.",
+		"...x.........x..",
+		"....xx.....xx...",
+		"......xxxxx.....",
+	};
+
+	sdl_paint_image(m, image, x, y);
+	if (!yes)
+		sdl_paint_image(m, not_xpm,  16+x, y);
+}
+
+static void sdl_paint_button(struct sdl *m, char **image, int x, int y, int yes)
+{
+	int bsx = m->wx/m->nx;
+	int bsy = m->wy/m->ny;
+	if (x < 0)
+		x += m->nx;
+	if (y < 0)
+		y += m->ny;
+	x = bsx/2 + x*bsx;
+	y = bsy/2 + y*bsy;
+	sdl_paint_boolean(m, image, x, y, yes);
+}
+
+static void sdl_paint_ui_focus(struct sdl *m, int f)
+{
+	static char *cm_xpm[] = {
+		"16 9 2 1",
+		"# c #ffffff",
+		". c #000000",
+		"................",
+		"................",
+		"................",
+		"....###..#.#.##.",
+		"...#.....##.#..#",
+		"...#.....#..#..#",
+		"...#.....#..#..#",
+		"....###..#..#..#",
+		"................",
+	};
+	double dioptr = 1/(f/100.);
+	int x, y;
+
+	if (dioptr > m->focus_min)
+		return;
+
+	sdl_icon_pos(m, &x, &y, cam_convert_focus(m, dioptr));
+	sdl_paint_image(m, cm_xpm, x, y);
+	sdl_number(m, x-12, y-15, 1, 3, f);
+}
+
+static void sdl_paint_ui_bias(struct sdl *m, double v)
+{
+	static char *bias_xpm[] = {
+		"16 12 2 1",
+		"# c #ffffff",
+		". c #000000",
+		"...#............",
+		"...#.......#....",
+		".#####....#.....",
+		"...#.....#......",
+		"...#....#.......",
+		".......#........",
+		"......#...#####.",
+		".....#..........",
+		"....#...........",
+		"...#............",
+		"................",
+		"................",
+	};
+	int x, y;
+
+	sdl_icon_pos(m, &x, &y, v);
+	sdl_paint_image(m, bias_xpm, x, y);
+}
+
+static void sdl_paint_slider(struct sdl *m)
+{
+	switch (m->slider_mode) {
+	case M_BIAS:
+		sdl_paint_ui_bias(m, 0.5);
+		return;
+	case M_EXPOSURE:
+		sdl_paint_ui_exposure(m, 10);
+		sdl_paint_ui_exposure(m, 100);
+		sdl_paint_ui_exposure(m, 999);
+		return;
+	case M_GAIN:
+		sdl_paint_ui_iso(m, 0/4., 100);
+		sdl_paint_ui_iso(m, 1/4., 200);
+		sdl_paint_ui_iso(m, 2/4., 400);
+		sdl_paint_ui_iso(m, 3/4., 800);
+		return;
+	case M_FOCUS:
+		sdl_paint_ui_focus(m, 100);
+		sdl_paint_ui_focus(m, 40);
+		sdl_paint_ui_focus(m, 25);
+		sdl_paint_ui_focus(m, 16);
+		sdl_paint_ui_focus(m, 10);
+		sdl_paint_ui_focus(m, 8);
+		sdl_paint_ui_focus(m, 6);
+		return;
+	}
+}
+
+static void sdl_paint_ui(struct sdl *m)
+{
+	static char *wait_xpm[] = {
+		"16 9 2 1",
+		"# c #ffffff",
+		". c #000000",
+		"....########....",
+		".....#....#.....",
+		".....#....#.....",
+		"......#..#......",
+		".......##.......",
+		"......#..#......",
+		".....#....#.....",
+		".....#....#.....",
+		"....########....",
+	};
+
+	static char *ok_xpm[] = {
+		"16 9 2 1",
+		"# c #ffffff",
+		". c #000000",
+		"...............#",
+		"............###.",
+		"..........##....",
+		"#.......##......",
+		".#.....#........",
+		"..#...#.........",
+		"..#..#..........",
+		"...##...........",
+		"...#............",
+	};
+
+	static char *exit_xpm[] = {
+		"16 9 2 1",
+		"x c #ffffff",
+		". c #000000",
+		"....x......x....",
+		".....x....x.....",
+		"......x..x......",
+		".......xx.......",
+		".......xx.......",
+		"......x..x......",
+		".....x....x.....",
+		"....x......x....",
+		"................",
+	};
+
+	static char *af_xpm[] = {
+		"16 12 2 1",
+		"x c #ffffff",
+		". c #000000",
+		"................",
+		"................",
+		".....xxxxxxx....",
+		".....x..........",
+		".....x..........",
+		".x...xxxxx......",
+		"x.x..x..........",
+		"xxx..x..........",
+		"x.x..x..........",
+		"x.x..x..........",
+		"................",
+		"................",
+	};
+
+	static char *ae_xpm[] = {
+		"16 12 2 1",
+		"x c #ffffff",
+		". c #000000",
+		"................",
+		"................",
+		".....xxxxxxx....",
+		".....x..........",
+		".....x..........",
+		".x...xxxxx......",
+		"x.x..x..........",
+		"xxx..x..........",
+		"x.x..x..........",
+		"x.x..xxxxxxx....",
+		"................",
+		"................",
+	};
+
+	static char *focus_xpm[] = {
+		"16 12 2 1",
+		"# c #ffffff",
+		". c #000000",
+		"................",
+		"................",
+		"###..........###",
+		"#..............#",
+		"#.....####.....#",
+		".....#....#.....",
+		".....#....#.....",
+		"#.....####.....#",
+		"#..............#",
+		"###..........###",
+		"................",
+		"................",
+	};
+
+	static char *flash_xpm[] = {
+		"16 12 2 1",
+		"# c #ffffff",
+		". c #000000",
+		"................",
+		"..........#.....",
+		"........##......",
+		".......##.......",
+		"......##........",
+		".....########...",
+		"..........##....",
+		".......#.##.....",
+		".......###......",
+		".......####.....",
+		"................",
+		"................",
+	};
+
+	static char *wb_xpm[] = {
+		"16 12 2 1",
+		"# c #ffffff",
+		". c #000000",
+		"................",
+		"................",
+		"................",
+		"#.....#..####...",
+		"#.....#..#...#..",
+		"#..#..#..####...",
+		"#..#..#..#...#..",
+		".##.##...####...",
+		"................",
+		"................",
+		"................",
+		"................",
+	};
+/* Template for more xpm's:
+	static char *empty_xpm[] = {
+		"16 12 2 1",
+		"# c #ffffff",
+		". c #000000",
+		"................",
+		"................",
+		"................",
+		"................",
+		"................",
+		"................",
+		"................",
+		"................",
+		"................",
+		"................",
+		"................",
+		"................",
+	};
+*/
+	SDL_FillRect(m->screen, NULL, SDL_MapRGB( m->liveview->format, 0, 0, 0 ));
+
+	{
+		/* Paint grid */
+		int x, y;
+		int nx = m->nx;
+		for (x=1; x<nx; x++) {
+			int x_ = (x*m->wx)/nx;
+			sdl_line_color(m, x_, 1, x_, m->wy-1, SDL_MapRGB( m->liveview->format, 40, 40, 40 ));
+		}
+
+		int ny = m->ny;
+		for (y=1; y<nx; y++) {
+			int y_ = (y*m->wy)/ny;
+			sdl_line_color(m, 1, y_, m->wx-1, y_, SDL_MapRGB( m->liveview->format, 40, 40, 40 ));
+		}
+
+	}
+
+	sdl_paint_image(m, wait_xpm,  m->wx/2,     m->wy/2);
+
+
+	sdl_paint_button(m, af_xpm, 0,  0, m->do_focus);
+	sdl_paint_button(m, ae_xpm, -1, 0, m->do_exposure);
+
+	sdl_paint_button(m, exit_xpm,   0, -1, 1);
+	sdl_paint_button(m, flash_xpm,  1, -1, m->do_flash);
+	sdl_paint_button(m, wb_xpm,     2, -1, m->do_white);
+	sdl_paint_button(m, focus_xpm, -1, -2, 1);
+	sdl_paint_button(m, ok_xpm,    -1, -1, 1);
+
+	sdl_paint_slider(m);
+	SDL_UpdateWindowSurface(m->window);
+}
+
+static double usec_to_time(double v)
+{
+	return 1/(v*.000001);
+}
+
+static void sdl_status(struct sdl *m, double avg)
+{
+	int ox = 0;
+	int oy = m->wy/2;
+	int s = 3;
+	SDL_Rect rcDest = { ox, oy, s*25, s*40 };
+
+	SDL_FillRect(m->screen, &rcDest, SDL_MapRGB( m->liveview->format, 30, 30, 30 ));
+
+	sdl_number(m, ox, oy, s, 3, avg*1000);
+	oy += s*10;
+
+	{
+		double focus, gain, exposure;
+
+		exposure = v4l2_g_ctrl(m->fd, V4L2_CID_EXPOSURE_ABSOLUTE);
+		gain = cam_get_gain_iso(m->dev);
+		focus = cam_get_focus_diopter(m);
+
+		double x = usec_to_time(exposure);
+		if (x > 999) x = 999;
+		sdl_number(m, ox, oy, s, 3, x);
+
+		oy += s*10;
+		if (gain > 999)
+			gain = 999;
+		sdl_number(m, ox, oy, s, 3, gain);
+
+		oy += s*10;
+		x = focus; /* diopters */
+		if (x == 0)
+			x = 999;
+		else
+			x = 100/x; /* centimeters */
+		sdl_number(m, ox, oy, s, 3, x);
+	}
+
+	SDL_UpdateWindowSurfaceRects(m->window, &rcDest, 1);
+}
+static pixel buf_pixel(struct v4l2_format *fmt, unsigned char *buf, int x, int y)
+{
+	pixel p = { 0, 0, 0, 0 };
+	int pos = x + y*fmt->fmt.pix.width;
+
+	p.alpha = 128;
+
+	switch (fmt->fmt.pix.pixelformat) {
+	case V4L2_PIX_FMT_SGRBG10:
+		{
+			short *b2 = (void *)buf;
+			x &= ~1;
+			y &= ~1;
+			p.g = b2[x + y*fmt->fmt.pix.width] /4;
+			p.r = b2[x + y*fmt->fmt.pix.width+1] /4;
+			p.b = b2[x + (y+1)*fmt->fmt.pix.width] /4;
+		}
+		break;
+
+	case V4L2_PIX_FMT_RGB24:
+		pos *= 3;
+		p.r = buf[pos];
+		p.g = buf[pos+1];
+		p.b = buf[pos+2];
+		break;
+
+	default:
+		printf("Wrong pixel format!\n");
+		fmt_print(fmt);
+		exit(1);
+	}
+
+	return p;
+}
+
+static char *fmt_name(struct v4l2_format *fmt)
+{
+	switch (fmt->fmt.pix.pixelformat) {
+	case V4L2_PIX_FMT_SGRBG10:
+		return "GRBG10";
+	case V4L2_PIX_FMT_RGB24:
+		return "RGB24";
+	default:
+		return "unknown";
+	}
+}
+
+static void sdl_handle_focus(struct sdl *m, float how)
+{
+	v4l2_set_control(m->fd, V4L2_CID_FOCUS_ABSOLUTE, 65535. * how);
+}
+
+static void sdl_key(struct sdl *m, int c)
+{
+	switch (c) {
+	case 27: exit(1); break;
+	case 'q': sdl_handle_focus(m, 0.); break;
+	case 'w': sdl_handle_focus(m, 1/6.); break;
+	case 'e': sdl_handle_focus(m, 1/3.); break;
+	case 'r': sdl_handle_focus(m, 1/2.); break;
+	case 't': sdl_handle_focus(m, 1/1); break;
+	case 'y': sdl_handle_focus(m, 1/.8); break;
+	case 'u': sdl_handle_focus(m, 1/.5); break;
+	case 'i': sdl_handle_focus(m, 1/.2); break;
+	case 'o': sdl_handle_focus(m, 1/.1); break;
+	case 'p': sdl_handle_focus(m, 1/.05); break;
+	default: printf("Unknown key %d / %c", c, c);
+	}
+}
+
+static int sdl_render_statistics(struct sdl *m)
+{
+	pixel white;
+	double focus, gain, exposure;
+
+	white.r = (Uint8)0xff;
+	white.g = (Uint8)0xff;
+	white.b = (Uint8)0xff;
+	white.alpha = (Uint8)128;
+
+	exposure = cam_get_exposure(m);
+	gain = v4l2_get_control(m->fd, 0x00980913) / 65535.;
+	focus = cam_get_focus(m);
+
+	for (int x=0; x<m->sx && x<m->sx*focus; x++)
+		sfc_put_pixel(m->liveview, x, 0, &white);
+
+	for (int y=0; y<m->sy && y<m->sy*gain; y++)
+		sfc_put_pixel(m->liveview, 0, y, &white);
+
+	for (int y=0; y<m->sy && y<m->sy*exposure; y++)
+		sfc_put_pixel(m->liveview, m->sx-1, y, &white);
+
+	for (int x=0; x<m->sx; x++)
+		sfc_put_pixel(m->liveview, x, m->sy-1, &white);
+
+	return 0;
+}
+
+static void sdl_render(struct sdl *m, unsigned char *buf, struct v4l2_format *fmt)
+{
+	float zoom = m->zoom;
+	if (!m->window)
+		return;
+
+	sdl_begin_paint(m);
+	int x0 = (fmt->fmt.pix.width - m->sx*m->factor/zoom)/2;
+	int y0 = (fmt->fmt.pix.height - m->sy*m->factor/zoom)/2;
+
+	for (int y = 0; y < m->sy; y++)
+		for (int x = 0; x < m->sx; x++) {
+			int x1 = x0+x*m->factor/zoom;
+			int y1 = y0+y*m->factor/zoom;
+			pixel p = buf_pixel(fmt, buf, x1, y1);
+			p.alpha = 128;
+			sfc_put_pixel(m->liveview, x, y, &p);
+		}
+
+	sdl_render_statistics(m);
+	sdl_finish_paint(m);
+}
+
+static void sdl_sync_settings(struct sdl *m)
+{
+	printf("Autofocus: "); v4l2_s_ctrl(m->fd, V4L2_CID_FOCUS_AUTO, m->do_focus);
+	printf("Autogain: " ); v4l2_s_ctrl(m->fd, V4L2_CID_AUTOGAIN, m->do_exposure);
+	printf("Autowhite: "); v4l2_s_ctrl(m->fd, V4L2_CID_AUTO_WHITE_BALANCE, m->do_white);
+	v4l2_s_ctrl(m->fd, 0x009c0901, m->do_flash ? 2 : 0);
+}
+
+static void sdl_init_window(struct sdl *m)
+{
+	if (m->do_full) {
+		m->wx = 800;
+		m->wy = 480;
+	} else {
+		m->wx = 800;
+		m->wy = 429;
+	}
+
+	SDL_SetWindowFullscreen(m->window, m->do_full*SDL_WINDOW_FULLSCREEN_DESKTOP);
+
+	m->screen = SDL_GetWindowSurface(m->window);
+	if (!m->screen) {
+		printf("Couldn't create screen\n");
+		exit(1);
+	}
+}
+
+static void sdl_init(struct sdl *m, struct dev_info *dev)
+{
+	m->fd = dev->fd;
+	m->dev = dev;
+
+	if (SDL_Init(SDL_INIT_VIDEO) < 0) {
+		printf("Could not init SDL\n");
+		exit(1);
+	}
+
+	atexit(SDL_Quit);
+
+	m->nx = 6;
+	m->ny = 4;
+
+	m->do_flash = 1;
+	m->do_focus = 0;
+	m->do_exposure = 1;
+	m->focus_min = 5;
+	m->do_white = 0;
+	m->do_big = 0;
+	m->do_full = 0;
+	m->zoom = 1;
+
+	m->window = SDL_CreateWindow("Camera", SDL_WINDOWPOS_UNDEFINED,
+				     SDL_WINDOWPOS_UNDEFINED, 800, 429,
+				     SDL_WINDOW_SHOWN |
+				     m->do_full * SDL_WINDOW_FULLSCREEN_DESKTOP);
+	if (m->window == NULL) {
+		printf("Window could not be created! SDL_Error: %s\n", SDL_GetError());
+		exit(1);
+	}
+
+	sdl_init_window(m);
+}
+
+static void sdl_set_size(struct sdl *m, int _sx)
+{
+	m->sx = _sx;
+	m->factor = (float) m->dev->fmt.fmt.pix.width / m->sx;
+	m->sy = m->dev->fmt.fmt.pix.height / m->factor;
+
+	m->bx = (m->wx-m->sx)/2;
+	m->by = (m->wy-m->sy)/2;
+
+	m->liveview = SDL_CreateRGBSurface(0,m->sx,m->sy,32,0,0,0,0);
+	if (!m->liveview) {
+		printf("Couldn't create liveview\n");
+		exit(1);
+	}
+
+	sdl_paint_ui(m);
+	sdl_sync_settings(m);
+}
+
+static struct sdl sdl;
+
+static void ppm_write(struct v4l2_format *fmt, unsigned char *img, char *out_name)
+{
+	FILE *fout;
+	fout = fopen(out_name, "w");
+	if (!fout) {
+		perror("Cannot open image");
+		exit(EXIT_FAILURE);
+	}
+	switch (fmt->fmt.pix.pixelformat) {
+	case V4L2_PIX_FMT_RGB24:
+		printf("ok\n");
+		break;
+	default:
+		printf("Bad pixel format\n");
+		exit(1);
+	}
+
+	fprintf(fout, "P6\n%d %d 255\n",
+		fmt->fmt.pix.width, fmt->fmt.pix.height);
+	fwrite(img, fmt->fmt.pix.width, 3*fmt->fmt.pix.height, fout);
+	fclose(fout);
+}
+
+/**
+   Write image to jpeg file.
+   \param img image to write
+*/
+static void jpeg_write(struct v4l2_format *fmt, unsigned char *img, char *jpegFilename)
+{
+	struct jpeg_compress_struct cinfo;
+	struct jpeg_error_mgr jerr;
+
+	JSAMPROW row_pointer[1];
+	FILE *outfile = fopen(jpegFilename, "wb");
+	if (!outfile) {
+		printf("Can't open jpeg for writing.\n");
+		exit(2);
+	}
+
+	/* create jpeg data */
+	cinfo.err = jpeg_std_error(&jerr);
+	jpeg_create_compress(&cinfo);
+	jpeg_stdio_dest(&cinfo, outfile);
+
+	/* set image parameters */
+	cinfo.image_width = fmt->fmt.pix.width;
+	cinfo.image_height = fmt->fmt.pix.height;
+	cinfo.input_components = 3;
+	switch (fmt->fmt.pix.pixelformat) {
+	case V4L2_PIX_FMT_SGRBG10:
+	case V4L2_PIX_FMT_RGB24:
+		cinfo.in_color_space = JCS_RGB;
+		break;
+	default:
+		printf("Need to specify colorspace!\n");
+		exit(1);
+	}
+
+	/* set jpeg compression parameters to default */
+	jpeg_set_defaults(&cinfo);
+	jpeg_set_quality(&cinfo, 90, TRUE);
+
+	jpeg_start_compress(&cinfo, TRUE);
+
+	/* feed data */
+	while (cinfo.next_scanline < cinfo.image_height) {
+		row_pointer[0] = &img[cinfo.next_scanline * cinfo.image_width *  cinfo.input_components];
+		jpeg_write_scanlines(&cinfo, row_pointer, 1);
+	}
+
+	jpeg_finish_compress(&cinfo);
+	jpeg_destroy_compress(&cinfo);
+	fclose(outfile);
+}
+
+static void any_write(struct dev_info *dev)
+{
+	char name[1024];
+	unsigned char *buf;
+	time_t t = time(NULL);
+	int ppm = 0;
+
+	buf = dev->buf;
+
+	sprintf(name, PICDIR "/delme_%d.%s", (int) t, ppm ? "ppm" : "jpg");
+	if (dev->fmt.fmt.pix.pixelformat != V4L2_PIX_FMT_RGB24) {
+		printf("Wrong pixel format\n");
+		exit(1);
+	}
+	if (ppm)
+		ppm_write(&dev->fmt, buf, name);
+	else
+		jpeg_write(&dev->fmt, buf, name);
+}
+
+static void sdl_mouse(struct sdl *m, SDL_Event event)
+{
+	int ax = 0, ay = 0;
+	int nx = event.button.x / (m->wx/m->nx), ny = event.button.y / (m->wy/m->ny);
+	if (nx >= m->nx/2)
+		nx -= m->nx;
+	if (ny >= m->ny/2)
+		ny -= m->ny;
+
+	printf("Button %d %d\n", nx, ny);
+
+	/* Virtual slider */
+	if (nx == -2) {
+		double value = (double) event.button.y / m->wy;
+		switch (m->slider_mode) {
+		case M_BIAS: {
+			double ev = value - .5; /* -.5 .. +.5 */
+			ev *= 3000;
+			printf("Exposure bias: %f mEV %d\n", ev, (int) ev);
+			if (v4l2_s_ctrl(m->fd, V4L2_CID_AUTO_EXPOSURE_BIAS, ev) < 0) {
+				printf("Could not set exposure bias\n");
+			}
+		}
+			return;
+		case M_EXPOSURE:
+			m->do_exposure = 0;
+			cam_set_exposure(m, value);
+			sdl_sync_settings(m);
+			return;
+		case M_GAIN:
+			m->do_exposure = 0;
+			v4l2_set_control(m->fd, 0x00980913, value * 65535);
+			sdl_sync_settings(m);
+			return;
+		case M_FOCUS:
+			cam_set_focus(m, value);
+			return;
+		}
+	}
+
+	switch (ny) {
+	case 0:
+		switch (nx) {
+		case 0:
+			m->do_focus ^= 1;
+			sdl_paint_ui(m);
+			sdl_sync_settings(m);
+			return;
+		case -1:
+			m->do_exposure ^= 1;
+			sdl_paint_ui(m);
+			sdl_sync_settings(m);
+			return;
+		}
+		break;
+	case 1:
+		switch (nx) {
+		case -1:
+			m->slider_mode = (m->slider_mode + 1) % M_NUM;
+			sdl_paint_ui(m);
+		}
+		break;
+	case -2:
+		switch (nx) {
+		case -1:
+			v4l2_s_ctrl(m->fd, V4L2_CID_AUTO_FOCUS_STATUS, 1);
+			return;
+		break;
+		}
+	case -1:
+		switch (nx) {
+		case 0:
+			exit(0);
+		case 1:
+			m->do_flash ^= 1;
+			sdl_paint_ui(m);
+			sdl_sync_settings(m);
+			return;
+		case 2:
+			m->do_white ^= 1;
+			sdl_paint_ui(m);
+			sdl_sync_settings(m);
+			return;
+		case -3:
+			m->do_big ^= 1;
+			if (m->do_big)
+				sdl_set_size(m, m->do_full ? 630:512);
+			else
+				sdl_set_size(m, 256);
+			return;
+		case -1:
+			sdl_paint_ui(m);
+			any_write(m->dev);
+			return;
+		}
+		break;
+	}
+
+	if (event.button.x > m->wx-m->bx)
+		ax = 1;
+	if (event.button.x < m->bx)
+		ax = -1;
+
+	if (event.button.y > m->wy-m->by)
+		ay = 1;
+	if (event.button.y < m->by)
+		ay = -1;
+
+	printf("mouse button at...%d, %d area %d, %d\n", event.button.x, event.button.y,
+	       ax, ay);
+}
+
+static void sdl_iteration(struct sdl *m)
+{
+	SDL_Event event;
+
+	while(SDL_PollEvent(&event)) {
+		switch(event.type) {
+		case SDL_QUIT:
+			exit(1);
+			break;
+		case SDL_KEYDOWN:
+			printf("key pressed... %c\n", event.key.keysym.sym);
+			/* SDLK_A, SDLK_LEFT, SDLK_RETURN, SDLK_BACKSPACE, SDLK_SPACE */
+			switch (event.key.keysym.sym) {
+			default: sdl_key(m, event.key.keysym.sym);
+			}
+			break;
+		case SDL_WINDOWEVENT:
+			if (event.window.event == SDL_WINDOWEVENT_EXPOSED)
+				sdl_paint_ui(m);
+			break;
+		case SDL_MOUSEBUTTONDOWN:
+			sdl_mouse(m, event);
+			break;
+		}
+	}
+}
+
+static void cam_open(struct dev_info *dev, char *name)
+{
+	struct v4l2_format *fmt = &dev->fmt;
+
+	dev->fd = v4l2_open(name, O_RDWR);
+	if (dev->fd < 0) {
+		printf("video %s open failed: %m\n", name);
+		exit(1);
+	}
+
+	fmt->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+	fmt->fmt.pix.pixelformat = V4L2_PIX_FMT_RGB24;
+	fmt->fmt.pix.field = V4L2_FIELD_NONE;
+	fmt->fmt.pix.width = SX;
+	fmt->fmt.pix.height = SY;
+
+	v4l2_s_ctrl(dev->fd, V4L2_CID_AUTO_FOCUS_STATUS, 0);
+	v4l2_set_focus(dev->fd, 50);
+
+	printf("ioctl = %d\n", v4l2_ioctl(dev->fd, VIDIOC_S_FMT, fmt));
+
+	printf("capture is %lx %s %d x %d\n", (unsigned long) fmt->fmt.pix.pixelformat, fmt_name(fmt), fmt->fmt.pix.width, fmt->fmt.pix.height);
+}
+
+/* ------------------------------------------------------------------ */
+
+
+static struct dev_info dev;
+
+int main(void)
+{
+	int i;
+	struct v4l2_format *fmt = &dev.fmt;
+
+	dtime();
+	cam_open(&dev, "/dev/video0");
+
+	sdl_init(&sdl, &dev);
+	sdl_set_size(&sdl, 256);
+
+	double loop = dtime(), max = 0, avg = .200;
+	if (dev.debug & D_TIMING)
+		printf("startup took %f\n", loop);
+
+	for (i=0; i<500000; i++) {
+		int num = v4l2_read(dev.fd, dev.buf, SIZE);
+		if (num < 0) {
+			printf("Could not read frame\n");
+			return 1;
+		}
+		{
+			double d = dtime();
+			sdl_render(&sdl, dev.buf, fmt);
+			if (dev.debug & D_TIMING)
+				printf("Render took %f\n", dtime() - d);
+		}
+		{
+			double d = dtime();
+			for (int i = 0; i<1; i++)
+				sdl_status(&sdl, avg);
+			if (dev.debug & D_TIMING)
+				printf("Status took %f\n", dtime() - d);
+		}
+
+		sdl_iteration(&sdl);
+		double now = dtime();
+		if (now - loop > max)
+			max = now - loop;
+		double c = 0.03;
+		avg = (now - loop) * c + avg * (1-c);
+		if (dev.debug & D_TIMING)
+			printf("Iteration %f, maximum %f, average %f\n", now-loop, max, avg);
+		loop = now;
+	}
+	return 0;
+}
