Is there a simple GStreamer Example for C++? - c++

Question

I am looking for simple example for GStreamer that uses Video-Streaming...
I would like to create a simple example (showing a video-output) incl. compilation instructions.

Answer 1

This will be the source code of a GStreamer pipeline videotestsrc ! autovideosink. It will show a nice video output...
Prerequisites
Make sure you have GStreamer and gcc installed.
Add the following source code to helloworld.c
#include <gst/gst.h>
#include <glib.h>
static gboolean bus_call (GstBus *bus, GstMessage *msg, gpointer data)
{
GMainLoop *loop = (GMainLoop *) data;
switch (GST_MESSAGE_TYPE (msg)) {
case GST_MESSAGE_EOS:
g_print ("End of stream\n");
g_main_loop_quit (loop);
break;
case GST_MESSAGE_ERROR: {
gchar *debug;
GError *error;
gst_message_parse_error (msg, &error, &debug);
g_free (debug);
g_printerr ("Error: %s\n", error->message);
g_error_free (error);
g_main_loop_quit (loop);
break;
}
default:
break;
}
return TRUE;
}
int main (int argc, char *argv[])
{
GMainLoop *loop;
GstElement *pipeline, *videotestsrcm, *autovideosinkm;
GstBus *bus;
guint bus_watch_id;
/* Initialisation */
gst_init (&argc, &argv);
loop = g_main_loop_new (NULL, FALSE);
/* Create gstreamer elements */
pipeline = gst_pipeline_new ("videotest-pipeline");
videotestsrcm = gst_element_factory_make ("videotestsrc", "testsource");
autovideosinkm = gst_element_factory_make ("autovideosink", "videosink");
if (!pipeline || !videotestsrcm || !autovideosinkm) {
g_printerr ("One element could not be created. Exiting.\n");
return -1;
}
/* Set up the pipeline */
/* we add a message handler */
bus = gst_pipeline_get_bus (GST_PIPELINE (pipeline));
bus_watch_id = gst_bus_add_watch (bus, bus_call, loop);
gst_object_unref (bus);
/* we add all elements into the pipeline */
gst_bin_add_many (GST_BIN (pipeline),
videotestsrcm, autovideosinkm, NULL);
/* we link the elements together */
/* videotestsrcm -> autovideosinkm */
gst_element_link (videotestsrcm, autovideosinkm);
/* Set the pipeline to "playing" state*/
g_print ("Now set pipeline in state playing");
gst_element_set_state (pipeline, GST_STATE_PLAYING);
/* Iterate */
g_print ("Running...\n");
g_main_loop_run (loop);
/* Out of the main loop, clean up nicely */
g_print ("Returned, stopping playback\n");
gst_element_set_state (pipeline, GST_STATE_NULL);
g_print ("Deleting pipeline\n");
gst_object_unref (GST_OBJECT (pipeline));
g_source_remove (bus_watch_id);
g_main_loop_unref (loop);
return 0;
}
Compile it
gcc -Wall helloworld.c -o helloworld $(pkg-config --cflags --libs gstreamer-1.0)
Run it
./helloworld