gstreamer 1.0 rtspsrc to rtph264depay cannot link - gstreamer

Question

I am trying to connect to a ubiquiti camera and successfully with the following command with gstreamer.
gst-launch-1.0 --gst-debug=4 rtspsrc location="rtsp://:554/live/ch00_0" ! rtph264depay ! h264parse ! openh264dec ! d3dvideosink
I look at the debug and it says could not link pads rtspsrc to rtph264depay.
Picture
but it gets the stream alright and can see the video. when I put this into a c project it says cannot link source to rtph264parse. I looked around it says to use a dynamic pad with the following code
static void on_pad_added (GstElement *element, GstPad *pad, gpointer data)
{
GstPad *sinkpad;
GstElement *decoder = (GstElement *) data;
/* We can now link this pad with the rtsp-decoder sink pad */
g_print ("Dynamic pad created, linking source/demuxer\n");
sinkpad = gst_element_get_static_pad (decoder, "sink");
gst_pad_link (pad, sinkpad);
gst_object_unref (sinkpad);
}
int main(int argc, char *argv[])
{
/* Initialize GStreamer */
gst_init(&argc,&argv);
/* Build Pipeline */
pipel.pipeline = gst_pipeline_new("My pipeline");
pipel.source = gst_element_factory_make ("rtspsrc","source");
g_object_set (G_OBJECT (pipel.source), "latency",2000,NULL);
pipel.rtppay = gst_element_factory_make( "rtph264depay", "depayl");
pipel.parse = gst_element_factory_make("h264parse","parse");
pipel.filter1 = gst_element_factory_make("capsfilter","filter");
pipel.decodebin = gst_element_factory_make ("openh264dec","decode");
pipel.sink = gst_element_factory_make("d3dvideosink","sink");
g_object_set (G_OBJECT (pipel.sink), "sync",FALSE,NULL);
//create_uri(url,url_size,ip_address,port);
g_object_set(GST_OBJECT(pipel.source),"location","rtsp://<IP>:554/live/ch00_0",NULL);
filtercaps = gst_caps_from_string("application/x-rtp");
g_object_set (G_OBJECT (pipel.filter1), "caps",filtercaps,NULL);
gst_caps_unref(filtercaps);
gst_bin_add_many (GST_BIN (pipel.pipeline),pipel.source
,pipel.rtppay
,pipel.parse
,pipel.decodebin
,pipel.sink
,NULL);
if(!gst_element_link(pipel.source,pipel.rtppay))
printf("\nFailed source to rtppay\n");
if(!gst_element_link_many(pipel.parse,pipel.decodebin,pipel.sink,NULL))
printf("\nFailed to link parse to sink");
g_signal_connect(pipel.rtppay, "pad-added", G_CALLBACK(on_pad_added), pipel.parse);
}

Answer 1

static void cb_new_rtspsrc_pad(GstElement *element,GstPad*pad,gpointer data)
{
gchar *name;
GstCaps * p_caps;
gchar * description;
GstElement *p_rtph264depay;
name = gst_pad_get_name(pad);
g_print("A new pad %s was created\n", name);
// here, you would setup a new pad link for the newly created pad
// sooo, now find that rtph264depay is needed and link them?
p_caps = gst_pad_get_pad_template_caps (pad);
description = gst_caps_to_string(p_caps);
printf("%s\n",p_caps,", ",description,"\n");
g_free(description);
p_rtph264depay = GST_ELEMENT(data);
// try to link the pads then ...
if(!gst_element_link_pads(element, name, p_rtph264depay, "sink"))
{
printf("Failed to link elements 3\n");
}
g_free(name);
}
/* ---------- Main --------------- */
int main(int argc, char *argv[])
{
/* Initialize GStreamer */
gst_init(&argc,&argv);
/* Build Pipeline */
pipel.pipeline = gst_pipeline_new("My pipeline");
creating_pipeline(ip_address,port);
pipel.source = gst_element_factory_make ("rtspsrc","source");
g_object_set (G_OBJECT (pipel.source), "latency",2000,NULL);
pipel.rtppay = gst_element_factory_make( "rtph264depay", "depayl");
pipel.parse = gst_element_factory_make("h264parse","parse");
pipel.filter1 = gst_element_factory_make("capsfilter","filter");
pipel.decodebin = gst_element_factory_make ("openh264dec","decode");
pipel.sink = gst_element_factory_make("d3dvideosink","sink");
g_object_set (G_OBJECT (pipel.sink), "sync",FALSE,NULL);
//create_uri(url,url_size,ip_address,port);
g_object_set(GST_OBJECT(pipel.source),"location","rtsp://<ip>:554/live/ch00_0",NULL);
filtercaps = gst_caps_from_string("application/x-rtp");
g_object_set (G_OBJECT (pipel.filter1), "caps",filtercaps,NULL);
gst_caps_unref(filtercaps);
gst_bin_add_many (GST_BIN (pipel.pipeline),pipel.source
,pipel.rtppay
,NULL);
// listen for newly created pads
g_signal_connect(pipel.source, "pad-added", G_CALLBACK(cb_new_rtspsrc_pad),pipel.rtppay);
gst_bin_add_many (GST_BIN (pipel.pipeline),pipel.parse,NULL);
if(!gst_element_link(pipel.rtppay,pipel.parse))
printf("\nNOPE\n");
gst_bin_add_many (GST_BIN (pipel.pipeline),pipel.decodebin
,pipel.sink
,NULL);
if(!gst_element_link_many(pipel.parse,pipel.decodebin,pipel.sink,NULL))
printf("\nFailed to link parse to sink");
g_signal_connect(pipel.rtppay, "pad-added", G_CALLBACK(on_pad_added), pipel.parse);
}
Works Now!
use cb_new_rtspsrc_pad to add the pad dynamically
add the parse to bin
link up between rtppay and parse
add the necessary elements the rest of the string to make it work.