From 41146c8902beeefb1cc166c612d5d7f855848c08 Mon Sep 17 00:00:00 2001
From: Benjamin Franzke <benjaminfranzke@googlemail.com>
Date: Fri, 25 May 2012 08:28:48 +0200
Subject: cvg: Add simple webcam capture

---
 cvg.c | 123 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 110 insertions(+), 13 deletions(-)

diff --git a/cvg.c b/cvg.c
index 293c2b1..da2062b 100644
--- a/cvg.c
+++ b/cvg.c
@@ -9,11 +9,15 @@ struct cvg {
 	GtkWidget *drawing_area2;
 	GtkButton *gauss_btn;
 	GtkButton *open_btn;
+	CvCapture *capture;
 	IplImage *image;
 	IplImage *output;
 	cairo_surface_t *input_surface;
 	cairo_surface_t *output_surface;
 	guint last_press;
+	int idle_source;
+
+	IplImage *(*filter)(struct cvg *cvg, IplImage *image);
 };
 
 static cairo_surface_t *
@@ -100,6 +104,64 @@ destroy_images(struct cvg *cvg)
 	cvg->output_surface = NULL;
 }
 
+static void
+update_right_drawing_area(struct cvg *cvg)
+{
+	if (!cvg->image)
+		return;
+
+	if (cvg->output)
+		cvReleaseImage(&cvg->output);
+
+	cvg->output = cvg->filter(cvg, cvg->image);
+
+	if (cvg->output_surface)
+		cairo_surface_destroy(cvg->output_surface);
+	cvg->output_surface = NULL;
+	if (cvg->output)
+		cvg->output_surface =
+			cairo_surface_create_from_ipl_image(cvg->output);
+	gtk_widget_queue_draw(cvg->drawing_area2);
+}
+
+static gboolean
+capture(gpointer userdata)
+{
+	struct cvg *cvg = userdata;
+	IplImage *image;
+
+	image = cvQueryFrame(cvg->capture);
+	if (!image) {
+		fprintf(stderr, "ERROR: frame is null...\n");
+		exit(EXIT_FAILURE);
+	}
+
+	if (cvg->image)
+		cvReleaseImage(&cvg->image);
+	if (cvg->input_surface)
+		cairo_surface_destroy(cvg->input_surface);
+
+	cvg->image = cvCreateImage(cvSize(image->width, image->height),
+				   image->depth, image->nChannels);
+	cvCopy(image, cvg->image, NULL);
+	if (!cvg->image)
+		return FALSE;
+	cvg->input_surface = cairo_surface_create_from_ipl_image(cvg->image);
+	gtk_widget_queue_draw(cvg->drawing_area1);
+	update_right_drawing_area(cvg);
+
+	return TRUE;
+}
+
+static void
+stop_capture(struct cvg *cvg)
+{
+	if (cvg->idle_source) {
+		g_source_remove(cvg->idle_source);
+		cvg->idle_source = 0;
+	}
+}
+
 gboolean
 key_event(GtkWidget *widget, GdkEventKey *event, gpointer userdata)
 {
@@ -136,6 +198,15 @@ key_event(GtkWidget *widget, GdkEventKey *event, gpointer userdata)
 			gtk_widget_queue_draw(cvg->drawing_area1);
 			gtk_widget_queue_draw(cvg->drawing_area2);
 			break;
+		case GDK_KEY_s:
+		case GDK_KEY_S:
+			stop_capture(cvg);
+			break;
+		case GDK_KEY_c:
+		case GDK_KEY_C:
+			if (!cvg->idle_source)
+				cvg->idle_source = g_idle_add(capture, cvg);
+			break;
 		case GDK_KEY_q:
 			gtk_main_quit();
 			break;
@@ -166,32 +237,40 @@ file_set(GtkFileChooserButton *widget, gpointer userdata)
 	struct cvg *cvg = userdata;
 	gchar *filename;
 
+	stop_capture(cvg);
+
 	filename = gtk_file_chooser_get_filename(GTK_FILE_CHOOSER(widget));
 	open_file(cvg, filename);
 	g_free(filename);
 
 	gtk_widget_queue_draw(cvg->drawing_area1);
+	update_right_drawing_area(cvg);
 }
 
-void
-on_gauss_button_click(GtkButton *button, gpointer userdata)
+static IplImage *
+gauss_filter(struct cvg *cvg, IplImage *image)
 {
-	struct cvg *cvg = userdata;
+	IplImage *output;
 
-	if (!cvg->image)
-		return;
+	output = cvCreateImage(cvGetSize(image), IPL_DEPTH_8U, 3);
+	cvSmooth(image, output, CV_GAUSSIAN, 9, 9, 0, 0);
 
-	if (cvg->output)
-		cvReleaseImage(&cvg->output);
+	return output;
+}
 
-	cvg->output = cvCreateImage(cvGetSize(cvg->image), IPL_DEPTH_8U, 3);
-	cvSmooth(cvg->image, cvg->output, CV_GAUSSIAN, 9, 9, 0, 0);
+static IplImage *
+none_filter(struct cvg *cvg, IplImage *image)
+{
+	return NULL;
+}
 
-	if (cvg->output_surface)
-		cairo_surface_destroy(cvg->output_surface);
-	cvg->output_surface = cairo_surface_create_from_ipl_image(cvg->output);
+void
+on_gauss_button_click(GtkButton *button, gpointer userdata)
+{
+	struct cvg *cvg = userdata;
 
-	gtk_widget_queue_draw(cvg->drawing_area2);
+	cvg->filter = gauss_filter;
+	update_right_drawing_area(cvg);
 }
 
 void
@@ -216,6 +295,7 @@ main(int argc, char *argv[])
 	GtkBuilder *builder;
 	GObject *file_chooser;
 	gchar *path, *file;
+	int index = 0;
 
 	memset(&cvg, 0, sizeof cvg);
 	gtk_init(&argc, &argv);
@@ -223,6 +303,21 @@ main(int argc, char *argv[])
 	if (argc >= 2)
 		open_file(&cvg, argv[argc-1]);
 
+	cvg.capture = cvCreateCameraCapture(index);
+	if (!cvg.capture) {
+		fprintf(stderr, "ERROR: capture is NULL \n");
+		exit(EXIT_FAILURE);
+	}
+
+#if 1
+	cvSetCaptureProperty(cvg.capture, CV_CAP_PROP_FRAME_WIDTH,  10000);
+	cvSetCaptureProperty(cvg.capture, CV_CAP_PROP_FRAME_HEIGHT, 10000);
+#endif
+
+	printf("width: %.f, height: %.f\n",
+	       cvGetCaptureProperty(cvg.capture, CV_CAP_PROP_FRAME_WIDTH),
+	       cvGetCaptureProperty(cvg.capture, CV_CAP_PROP_FRAME_HEIGHT));
+
 	builder = gtk_builder_new();
 	path = g_path_get_dirname(argv[0]);
 	file = g_build_filename(path, "cvg.ui", NULL);
@@ -245,6 +340,8 @@ main(int argc, char *argv[])
 	gtk_container_forall(GTK_CONTAINER(file_chooser),
 			     find_button, &cvg.open_btn);
 
+	cvg.idle_source = g_idle_add(capture, &cvg);
+	cvg.filter = none_filter;
 	gtk_widget_show_all(GTK_WIDGET(gtk_builder_get_object(builder, "win")));
 	g_object_unref(builder);
 	gtk_main();
-- 
cgit