+/* gst-perspective-example - test program for the GStreamer perspective 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), "matrix", va, NULL);
+ g_value_array_free(va);
+}
+
+int main(void)
+{
+ GstElement *pipeline, *src, *capsfilter, *perspective, *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);
+
+ perspective = gst_element_factory_make("perspective", NULL);
+ set_matrix(perspective);
+
+ 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, perspective, conv, sink, NULL);
+ ret = gst_element_link_many(src, capsfilter, perspective, 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;
+}
projects / experiments / gstreamer.git / commitdiff