rtspsrc - pad-added signal - correct handling

[Bill Klein]

I am using a pipeline with an rtsp src in C code. Everything has been
working mostly wonderfully, but recent issues have led me to believe that I
am doing something wrong in certain situations. Specifically, I am
wondering if I am handling the *pad-added* signal correctly.

My pad-added handler is something simple like (simplified for the sake of
readability):

void on_pad_added(GstElement* element, GstPad* pad, void *data) {
    GstPad* sinkpad = gst_element_get_static_pad(depay_el, "sink");
    if(!sinkpad) ... // handle error

    auto r = gst_pad_link(pad, sinkpad);

    auto padnm = gst_pad_get_name(pad);
    log("on_pad_added - "+padnm+" result:"+getPadLinkRespStr(rs));
    // free paddnm...

    gst_object_unref(sinkpad);
}


A few questions about this:

   - Is the above correct/sufficient?

   - Sometimes gst_pad_link returns GST_PAD_LINK_NOFORMAT. Is that
   expected/normal? Do I need to perform additional handling in that case (ex
   unrefing the element)?

   - Sometimes gst_pad_link returns GST_PAD_LINK_WAS_LINKED. Is that
   expected/normal? Do I need to perform additional handling in that case (ex
   unrefing the element)?

   - For some networks/rtsp cameras, I see only a few pad-added signals
   called. In others, I see 100s (recv_rtp_src_***). Is that normal?

Thank you!

- Bill
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