How to link v4l2src to capsfilter in c for gstreamer-1.14 - gstreamer

Question

I have a gstreamer media pipeline as shown below which I am trying to convert into a c code. The command line works fine.
gst-launch-1.0 v4l2src device=/dev/video1 ! capsfilter caps=video/x-raw,width=1280,height=720,format=UYVY ! queue ! videoconvert ! queue ! capsfilter caps=video/x-raw,format=NV12,width=1280,height=720,pixel-aspect-ratio=1/1 ! v4l2h264enc extra-controls="controls,h264_level=12,h264_profile=1" ! h264parse ! autovideosink
I have written the code and compilation is successful. When, I execute the code, the videosrc element is unable to link to capsfilter. I have surfed through the internet and was unsuccessful in rectifying the problem. Can someone help in correcting me what, I am doing wrong.
The code snippet is below:
/* Create the gstreamer elements */
source = gst_element_factory_make ("v4l2src", "source");
capsfilter = gst_element_factory_make ("capsfilter", "Caps-Filter");
capsfilter2 = gst_element_factory_make ("capsfilter", "caps-filter2");
video_convert = gst_element_factory_make ("videoconvert", "Video Convert");
queue1 = gst_element_factory_make ("queue", "Encoded Video Queue 1");
queue2 = gst_element_factory_make ("queue", "Encoded Video Queue 2");
encoder = gst_element_factory_make ("v4l2h264enc", "HW Accelerated Encoder");
H264_pay = gst_element_factory_make ("h264parse", "Payload-encode H264 video into RTP packets");
sink = gst_element_factory_make("autovideosink", "sink");
/* Create the empty pipeline */
pipeline = gst_pipeline_new ("test-pipeline");
if(!source || !capsfilter || ! capsfilter2 || !video_convert || !queue1 || !queue2 || !encoder || !H264_pay || !sink)
/* Set Source element properties */
g_object_set (G_OBJECT(source), "device", "/dev/video1", NULL);
GstCaps* filtercaps = gst_caps_from_string("video/x-raw,width=1280,height=720,format=(string)UYUY");
GstCaps* vconvertfilter = gst_caps_from_string("video/x-raw,width=1280,height=720,format=(string)NV12,pixel-aspect-ratio=1/1");
GstStructure *test = gst_structure_new_from_string("controls,h264_level=12,h264_profile=1");
g_object_set(G_OBJECT(capsfilter), "caps", filtercaps,NULL);
g_object_set(G_OBJECT(capsfilter2), "caps", vconvertfilter, NULL);
g_object_set (G_OBJECT(encoder), "extra-controls", test, NULL);
gst_caps_unref(filtercaps);
gst_caps_unref(vconvertfilter);
/* Link all elements that can be automatically linked because they have "Always" pads */
gst_bin_add_many (GST_BIN (pipeline),
source, capsfilter,
queue1, video_convert, queue2,
capsfilter2, encoder,
H264_pay, sink, NULL);
if(!gst_element_link(source, capsfilter))
{
g_printerr("Unable to link Source to filter. check your caps. \n");
gst_object_unref (pipeline);
}
if (gst_element_link_many (capsfilter, queue1, video_convert, NULL) != TRUE)
{
g_printerr("Capsfilter could not be linked to queue1. \n");
gst_object_unref (pipeline);
}
if (gst_element_link_many (video_convert, queue2, capsfilter2, encoder, H264_pay, NULL) != TRUE)
{
g_printerr("video_convert could not be linked to queue2. \n");
gst_object_unref (pipeline);
}
if(gst_element_link_many (H264_pay, sink, NULL) != TRUE)
{
g_printerr("parse could not link to sink.\n");
gst_object_unref (pipeline);
}
I get the error as below;
Unable to link Source to filter. check your caps.
Can somebody help me correct the mistake?