Dynamically record a h264 stream

[Davide Tuccilli]

I have a pipeline like this:

v4l2src device=/dev/video0 ! video/x-h264  ! tee ! queue ! h264parse ! 
omxh264dec ! glimagesink

And the stream is correctly displayed. I want to dynamically attach a 
branch to the tee to save the stream into a mp4 file, and I'm using this 
code to attach the recording branch:

     m_recordPad = gst_element_get_request_pad(m_tee, "src_%u");

     GstElement * queue     = gst_element_factory_make("queue", "recqueue");
     GstElement * h264parse = gst_element_factory_make("h264parse", 
"rech264parse");
     GstElement * mux       = gst_element_factory_make("mp4mux", "recmux");
     GstElement * fileSink  = gst_element_factory_make("filesink", 
"recfilesink");

     g_object_set(G_OBJECT(fileSink), "location", filename, nullptr);

     gst_bin_add_many(GST_BIN(m_pipeline), queue, h264parse, mux, 
fileSink, nullptr);

     if (gst_element_link_many(queue, h264parse, mux, fileSink, nullptr)) {

         GstPad * sinkpad = gst_element_get_static_pad(queue, "sink");

         gst_element_sync_state_with_parent(queue);
         gst_element_sync_state_with_parent(h264parse);
         gst_element_sync_state_with_parent(mux);
         gst_element_sync_state_with_parent(fileSink);

         if (!GST_PAD_LINK_FAILED(gst_pad_link(m_recordPad, sinkpad))) {
             return true;
         }

         gst_object_unref(sinkpad);

     }

     return false;

It should be extremely similiar to what I've found here 
https://coaxion.net/blog/2014/01/gstreamer-dynamic-pipelines/

Now, when I try to start recording, every frame is dropped with messages 
like this:

0:01:23.413955057  1546 0x6bb03340 WARN               h264parse 
gsth264parse.c:1205:gst_h264_parse_handle_frame:<rech264parse> 
broken/invalid nal Type: 1 Slice, Size: 6860 will be dropped

Am I doing this wrong? How can h264parse fail on the recording branch 
when it succeeds on the decoding one?