live: Add digital zoom support

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

1 files changed, 184 insertions, 1 deletions

diff --git a/live.c b/live.c
index 7fb4701..8ae386c 100644
--- a/live.c
+++ b/live.c
@@ -42,6 +42,7 @@
 #include <sys/types.h>
 
 #include <linux/fb.h>
+#include <linux/input.h>
 #include <linux/spi/spidev.h>
 
 #include "isp/list.h"
@@ -71,6 +72,13 @@ static struct iq_tuning *iq = NULL;
 
 static struct events events;
 
+struct input {
+	int fd;
+	float zoom;
+	float x;
+	float y;
+};
+
 /* -----------------------------------------------------------------------------
  * Image quality
  */
@@ -152,6 +160,177 @@ static struct omap3_isp_operations isp_ops = {
 };
 
 /* -----------------------------------------------------------------------------
+ * Input device
+ */
+
+static void input_process(void *priv)
+{
+	struct input_event iev[8];
+	struct input *input = priv;
+	float last_x = input->x;
+	float last_y = input->y;
+	float last_zoom = input->zoom;
+	unsigned int i;
+	ssize_t nbytes;
+
+	nbytes = read(input->fd, iev, sizeof iev);
+
+	for (i = 0; i < nbytes / sizeof iev[0]; ++i) {
+		if (iev[i].type != EV_REL)
+			continue;
+
+		switch (iev[i].code) {
+		case REL_X:
+			input->x += iev[i].value * 0.01;
+			input->x = clamp(input->x, 0.0, 1.0);
+			break;
+
+		case REL_Y:
+			input->y += iev[i].value * 0.01;
+			input->y = clamp(input->y, 0.0, 1.0);
+			break;
+
+		case REL_WHEEL:
+			input->zoom += iev[i].value * 0.1;
+			input->zoom = clamp(input->zoom, 1.0, 4.0);
+			break;
+		}
+	}
+
+	if (input->x == last_x && input->y == last_y &&
+	    input->zoom == last_zoom)
+		return;
+
+	omap3_isp_viewfinder_pan_zoom(isp, input->x, input->y, input->zoom);
+}
+
+static const char *input_find_device(void)
+{
+	unsigned int rel_mask = (1 << REL_X) | (1 << REL_Y) | (1 << REL_WHEEL);
+	unsigned int input_idx = 256;
+	unsigned int major;
+	unsigned int minor;
+	struct stat devstat;
+	struct dirent *ent;
+	static char path[50];
+	char buffer[16];
+	unsigned int rel;
+	char *end;
+	DIR *dir;
+	int ret;
+	int fd;
+
+	/* Locate the first mouse device in sysfs that supports X, Y and wheel
+	 * relative axis.
+	 */
+	dir = opendir("/sys/class/input");
+	if (dir == NULL)
+		return NULL;
+
+	while ((ent = readdir(dir)) != NULL) {
+
+		if (strncmp(ent->d_name, "event", 5))
+			continue;
+
+		sprintf(path, "/sys/class/input/%s/device/capabilities/rel",
+			ent->d_name);
+
+		fd = open(path, O_RDONLY);
+		if (fd == -1)
+			continue;
+
+		ret = read(fd, buffer, sizeof buffer - 1);
+		close(fd);
+		if (ret < 0)
+			continue;
+
+		buffer[ret] = '\0';
+		rel = strtoul(buffer, &end, 16);
+		if (*end != '\0' && *end != '\n')
+			continue;
+
+		if ((rel & rel_mask) != rel_mask)
+			continue;
+
+		input_idx = strtoul(ent->d_name + 5, NULL, 10);
+		break;
+	}
+
+	closedir(dir);
+
+	if (input_idx == 256)
+		return NULL;
+
+	/* Read the device major and minor from sysfs. */
+	sprintf(path, "/sys/class/input/event%u/dev", input_idx);
+	fd = open(path, O_RDONLY);
+	if (fd == -1)
+		return NULL;
+
+	ret = read(fd, buffer, sizeof buffer - 1);
+	close(fd);
+	if (ret < 0)
+		return NULL;
+
+	buffer[ret] = '\0';
+	major = strtoul(buffer, &end, 10);
+	if (*end != ':')
+		return NULL;
+
+	minor = strtoul(end + 1, &end, 10);
+	if (!isspace(*end) && end != '\0')
+		return NULL;
+
+	/* Verify that the device node exists. udev might have reordered the
+	 * device nodes, make sure the major/minor match as a sanity check. We
+	 * should really use libudev.
+	 */
+	sprintf(path, "/dev/input/event%u", input_idx);
+	ret = stat(path, &devstat);
+	if (ret < 0)
+		return NULL;
+
+	if (major(devstat.st_rdev) != major || minor(devstat.st_rdev) != minor)
+		return NULL;
+
+	return path;
+}
+
+static int input_init(struct input *input)
+{
+	const char *devname;
+
+	input->fd = -1;
+	input->zoom = 1.0;
+	input->x = 0.5;
+	input->y = 0.5;
+
+	devname = input_find_device();
+	if (devname == NULL) {
+		printf("No compatible input device found, disabling digital zoom\n");
+		return -ENODEV;
+	}
+
+	input->fd = open(devname, O_RDWR);
+	if (input->fd == -1)
+		return -errno;
+
+	events_watch_fd(&events, input->fd, OMAP3_ISP_EVENT_READ, input_process,
+			input);
+
+	return 0;
+}
+
+static void input_cleanup(struct input *input)
+{
+	if (input->fd == -1)
+		return;
+
+	events_unwatch_fd(&events, input->fd);
+	close(input->fd);
+}
+
+/* -----------------------------------------------------------------------------
  * Video output
  */
 
@@ -415,13 +594,14 @@ int main(int argc __attribute__((__unused__)), char *argv[] __attribute__((__unu
 	const char *vo_devname;
 	unsigned int colorkey;
 	bool enable_aewb = true;
+	struct input input;
 	float fps;
 	int ret;
 	int c;
 
 	iq_params_init(&iq_params);
 
-	while ((c = getopt_long(argc, argv, "b:hs:", opts, NULL)) != -1) {
+	while ((c = getopt_long(argc, argv, "b:hs:z", opts, NULL)) != -1) {
 		switch (c) {
 		case 'b':
 			buffers = atoi(optarg);
@@ -455,6 +635,7 @@ int main(int argc __attribute__((__unused__)), char *argv[] __attribute__((__unu
 	}
 
 	events_init(&events);
+	input_init(&input);
 
 	memset(&rect, 0, sizeof rect);
 	ret = fb_init(&rect);
@@ -564,6 +745,8 @@ int main(int argc __attribute__((__unused__)), char *argv[] __attribute__((__unu
 	exit_code = EXIT_SUCCESS;
 
 cleanup:
+	input_cleanup(&input);
+
 	/* Cleanup the ISP and video output resources. */
 	if (isp)
 		omap3_isp_close(isp);