X-Git-Url: https://git.ao2.it/experiments/gstreamer.git/blobdiff_plain/9371b7d21875e6a8ae1c79765e462b77fef0c601..ae0b8a944a0e5aeb654cac1d938be255733e26c9:/c/gst-matrix-example/gst-matrix-example.c

diff --git a/c/gst-matrix-example/gst-matrix-example.c b/c/gst-matrix-example/gst-matrix-example.c
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+/* gstmatrix-example - test program for the GStreamer matrix element
+ *
+ * Copyright (C) 2013  Antonio Ospite <ospite@studenti.unina.it>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/* FIXME: suppress warnings for deprecated API such as GValueArray
+ * with newer GLib versions (>= 2.31.0)
+ * 
+ * It is just not possible to switch to GArray yet because the python API in
+ * 1.2.0 still passes iterable properties as GValueArray */
+#define GLIB_DISABLE_DEPRECATION_WARNINGS
+#include <gst/gst.h>
+
+static gboolean on_message(GstBus *bus, GstMessage *message, gpointer user_data)
+{
+	GMainLoop *loop = (GMainLoop *)user_data;
+
+	switch (GST_MESSAGE_TYPE(message)) {
+	case GST_MESSAGE_ERROR:
+		g_error("Got ERROR");
+		g_main_loop_quit(loop);
+		break;
+	case GST_MESSAGE_WARNING:
+		g_warning("Got WARNING");
+		g_main_loop_quit(loop);
+		break;
+	case GST_MESSAGE_EOS:
+		g_main_loop_quit(loop);
+		break;
+	default:
+		break;
+	}
+
+	return TRUE;
+}
+
+static void set_matrix(GstElement *element)
+{
+	GValueArray *va;
+	GValue v = { 0, };
+	gdouble m[9];
+	guint i;
+
+	/* Initialize a 2D perspective matrix, you can use
+	 * cvGetPerspectiveTransform() from OpenCV to build it
+	 * from a quad-to-quad transformation */
+	m[0] = 1.9999999999999982;
+	m[1] = 0.8333333333333287;
+	m[2] = -399.99999999999926;
+	m[3] = 3.9968028886505525e-15;
+	m[4] = 1.9999999999999978;
+	m[5] = -8.277822871605139e-13;
+	m[6] = 2.428612866367518e-18;
+	m[7] = 0.0020833333333333294;
+	m[8] = 0.9999999999999996;
+
+	va = g_value_array_new(1);
+
+	g_value_init(&v, G_TYPE_DOUBLE);
+	for (i = 0; i < 9; i++) {
+		g_value_set_double(&v, m[i]);
+		g_value_array_append(va, &v);
+		g_value_reset(&v);
+	}
+	g_object_set(G_OBJECT(element), "m", va, NULL);
+	g_value_array_free(va);
+}
+
+int main(void)
+{
+	GstElement *pipeline, *src, *capsfilter, *matrix, *conv, *sink;
+	GstCaps *caps;
+	GstBus *bus;
+	GMainLoop *loop;
+	int ret;
+
+	gst_init(NULL, NULL);
+
+	pipeline = gst_element_factory_make("pipeline", NULL);
+
+	src = gst_element_factory_make("videotestsrc", NULL);
+
+	caps = gst_caps_from_string("video/x-raw,format=AYUV,width=800,height=480");
+
+	capsfilter = gst_element_factory_make("capsfilter", NULL);
+	g_object_set(G_OBJECT(capsfilter), "caps", caps, NULL);
+
+	matrix = gst_element_factory_make("matrix", NULL);
+	set_matrix(matrix);
+
+	conv = gst_element_factory_make("videoconvert", NULL);
+
+	sink = gst_element_factory_make("autovideosink", NULL);
+	g_return_val_if_fail(sink != NULL, -1);
+
+	gst_bin_add_many(GST_BIN(pipeline), src, capsfilter, matrix, conv, sink, NULL);
+	ret = gst_element_link_many(src, capsfilter, matrix, conv, sink, NULL);
+	if (!ret) {
+		g_error("Failed to link elements");
+		return -2;
+	}
+
+	loop = g_main_loop_new(NULL, FALSE);
+
+	bus = gst_pipeline_get_bus(GST_PIPELINE(pipeline));
+	gst_bus_add_signal_watch(bus);
+	g_signal_connect(G_OBJECT(bus), "message", G_CALLBACK(on_message),
+			 loop);
+	gst_object_unref(GST_OBJECT(bus));
+
+	ret = gst_element_set_state(pipeline, GST_STATE_PLAYING);
+	if (ret == GST_STATE_CHANGE_FAILURE) {
+		g_error("Failed to go into PLAYING state");
+		return -3;
+	}
+
+	g_main_loop_run(loop);
+
+	gst_element_set_state(pipeline, GST_STATE_NULL);
+
+	g_main_loop_unref(loop);
+	gst_object_unref(pipeline);
+
+	return 0;
+}