(process:20411): GStreamer-CRITICAL **: gst_pad_set_caps: assertion `caps == NULL || gst_caps_is_fixed (caps)' failed

Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 1094089648 (LWP 20420)]
0x4023847f in g_type_check_instance_is_a () from /opt/gnome/lib/libgobject-2.0.so.0
(gdb) bt
#0  0x4023847f in g_type_check_instance_is_a () from /opt/gnome/lib/libgobject-2.0.so.0
#1  0x4010d533 in gst_object_unref (object=0x3dfd9c0c) at gstobject.c:301
#2  0x4070e265 in gst_base_transform_chain (pad=0x80bc4e8, buffer=0x80a3ce8) at gstbasetransform.c:1235
#3  0x4012cf35 in gst_pad_chain (pad=0x80bc4e8, buffer=0x80a3ce8) at gstpad.c:2976
#4  0x4012d4fd in gst_pad_push (pad=0x8111848, buffer=0x80a3ce8) at gstpad.c:3066
#5  0x4070e257 in gst_base_transform_chain (pad=0x8111688, buffer=0x80a3ce8) at gstbasetransform.c:1231
#6  0x4012cf35 in gst_pad_chain (pad=0x8111688, buffer=0x80a3ce8) at gstpad.c:2976
#7  0x4012d4fd in gst_pad_push (pad=0x8111038, buffer=0x80a3ce8) at gstpad.c:3066
#8  0x40d129ad in gst_adder_collected (pads=0x81111e8, user_data=0x81108f0) at gstadder.c:393
#9  0x4070ffaf in gst_collectpads_chain (pad=0x810f708, buffer=0x80a5980) at gstcollectpads.c:549
#10 0x4012cf35 in gst_pad_chain (pad=0x810f708, buffer=0x80a5980) at gstpad.c:2976
#11 0x4012d4fd in gst_pad_push (pad=0x81084e8, buffer=0x80a5980) at gstpad.c:3066
#12 0x4070b262 in gst_base_src_loop (pad=0x81084e8) at gstbasesrc.c:684
---Type <return> to continue, or q <return> to quit---
#13 0x40140be4 in gst_task_func (task=0x80a3c88, tclass=0x80a3990) at gsttask.c:146
#14 0x403f58f9 in g_thread_pool_push () from /opt/gnome/lib/libglib-2.0.so.0
#15 0x403f3fb9 in g_thread_create_full () from /opt/gnome/lib/libglib-2.0.so.0
#16 0x40373aa7 in start_thread () from /lib/tls/libpthread.so.0
#17 0x404edc2e in clone () from /lib/tls/libc.so.6
(