Commit eb05020f authored by Stefan Kost's avatar Stefan Kost

examples: update hello world example

Our helloworld example thatw e reference from the manual has been a bit
complicated to serve a first contact with gstreamer. Since we have and
promote playbin2 as a playback api use it here.

Based on work from Mathias Hasselmann <mathias.hasselmann@gmx.de>

Fixes #424143
parent 0e6aa693
#include <stdlib.h>
#include <gst/gst.h>
static void
event_loop (GstElement * pipe)
static gboolean
bus_call (GstBus * bus, GstMessage * msg, gpointer data)
{
GstBus *bus;
GstMessage *message = NULL;
gboolean running = TRUE;
bus = gst_element_get_bus (GST_ELEMENT (pipe));
while (running) {
message = gst_bus_poll (bus, GST_MESSAGE_ANY, -1);
g_assert (message != NULL);
switch (message->type) {
case GST_MESSAGE_EOS:
running = FALSE;
break;
case GST_MESSAGE_WARNING:{
GError *gerror;
gchar *debug;
gst_message_parse_warning (message, &gerror, &debug);
gst_object_default_error (GST_MESSAGE_SRC (message), gerror, debug);
g_error_free (gerror);
g_free (debug);
break;
}
case GST_MESSAGE_ERROR:{
GError *gerror;
gchar *debug;
gst_message_parse_error (message, &gerror, &debug);
gst_object_default_error (GST_MESSAGE_SRC (message), gerror, debug);
g_error_free (gerror);
g_free (debug);
running = FALSE;
break;
}
default:
break;
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;
}
gst_message_unref (message);
}
gst_object_unref (bus);
}
case GST_MESSAGE_ERROR:{
gchar *debug;
GError *err;
int
main (int argc, char *argv[])
{
GstElement *bin, *filesrc, *decoder, *audiosink;
GstElement *conv, *resample;
gst_message_parse_error (msg, &err, &debug);
g_free (debug);
gst_init (&argc, &argv);
g_print ("Error: %s\n", err->message);
g_error_free (err);
g_main_loop_quit (loop);
if (argc != 2) {
g_print ("usage: %s <mp3 file>\n", argv[0]);
exit (-1);
break;
}
default:
break;
}
return TRUE;
}
/* create a new bin to hold the elements */
bin = gst_pipeline_new ("pipeline");
g_assert (bin);
gint
main (gint argc, gchar * argv[])
{
GstElement *playbin;
GMainLoop *loop;
GstBus *bus;
gchar *uri;
/* create a disk reader */
filesrc = gst_element_factory_make ("filesrc", "disk_source");
g_assert (filesrc);
g_object_set (G_OBJECT (filesrc), "location", argv[1], NULL);
gst_init (&argc, &argv);
/* now it's time to get the decoder */
decoder = gst_element_factory_make ("mad", "decode");
if (!decoder) {
g_print ("could not find plugin \"mad\"");
return -1;
if (argc < 2) {
g_print ("usage: %s <media file or uri>\n", argv[0]);
return 1;
}
/* also, we need to add some converters to make sure the audio stream
* from the decoder is converted into a format the audio sink can
* understand (if necessary) */
conv = gst_element_factory_make ("audioconvert", "audioconvert");
if (!conv) {
g_print ("could not create \"audioconvert\" element!");
return -1;
}
resample = gst_element_factory_make ("audioresample", "audioresample");
if (!resample) {
g_print ("could not create \"audioresample\" element!");
return -1;
playbin = gst_element_factory_make ("playbin2", NULL);
if (!playbin) {
g_print ("'playbin2' gstreamer plugin missing\n");
return 1;
}
/* and an audio sink */
audiosink = gst_element_factory_make ("alsasink", "play_audio");
g_assert (audiosink);
/* add objects to the main pipeline */
gst_bin_add_many (GST_BIN (bin), filesrc, decoder, conv,
resample, audiosink, NULL);
/* take the commandline argument and ensure that it is a uri */
if (gst_uri_is_valid (argv[1]))
uri = g_strdup (argv[1]);
else
uri = gst_filename_to_uri (argv[1], NULL);
g_object_set (playbin, "uri", uri, NULL);
g_free (uri);
/* link the elements */
gst_element_link_many (filesrc, decoder, conv, resample, audiosink, NULL);
/* create and event loop and feed gstreamer bus mesages to it */
loop = g_main_loop_new (NULL, FALSE);
/* start playing */
gst_element_set_state (bin, GST_STATE_PLAYING);
bus = gst_element_get_bus (playbin);
gst_bus_add_watch (bus, bus_call, loop);
g_object_unref (bus);
/* Run event loop listening for bus messages until EOS or ERROR */
event_loop (bin);
/* start play back and listed to events */
gst_element_set_state (playbin, GST_STATE_PLAYING);
g_main_loop_run (loop);
/* stop the bin */
gst_element_set_state (bin, GST_STATE_NULL);
/* cleanup */
gst_element_set_state (playbin, GST_STATE_NULL);
g_object_unref (playbin);
g_object_unref (loop);
exit (0);
return 0;
}
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