error when creating player element in GStreamer in Ubuntu

[ab]

Hello All,

I am facing error when I am creating player.

when am creating the player element as follows
player = gst_element_factory_make("oggvorbisplayer", "player");

g_object_set(player, "location" , argv[1] ,NULL);

gst_element_set_state(GST_ELEMENT(player), GST_STATE_PLAYING);

I am getting these errors:

$./prac2 Hello.ogg

(prac2:1870): GLib-GObject-CRITICAL **: g_object_set: assertion `G_IS_OBJECT (object)' failed

(prac2:1870): GStreamer-CRITICAL **: gst_element_set_state: assertion `GST_IS_ELEMENT (element)' failed


I have installed in my Ubuntu machine (Ubuntu 10.04.2 LTS) the following GStreamer plugins :
gstreamer0.10-tools 0.10.28.1
gstreamer0.10-alsa 0.10.28.1
gstreame0.10-ffmpeg 0.10.10.1
gstreamer-plugin-base 0.10.28.1
gstreamer-plugin-good 0.10.21
gstreamer-plugin-ugly 0.10.14.1
gstreamer-plugin-ugly-m 0.10.14
gstreamer-plugin-bad 0.10.18
totem 2.30.2

Please correct me what I am doing wrong.
Thanks in advance.

[ab]

Please accept my question and answer please.