[gst-devel] Problem inheriting from GstVideoSink class

[Maupin, Chase]

All,

I am working on writing a video sink and I am trying to inherit from the GstVideoSink class so that I get functionality such as dropping frames that are past their display time.  I have a reference video sink which uses this class and for experimentation purposes I placed a 1 second delay in the render function.  I observed that the display times in the buffers given to the sink were now 1 second apart and the video was skipping as I would expect.  I put the same delay in my video sink and I am still seeing time stamps that are only .033 seconds apart.  Basically the frames that should have been thrown away during the delay are just getting queued up and arrive in order after the delay.

I am doing the following to inherit from the GstVideoSink class:

- In my .c code I am using
	#define _do_init(bla) \
		GST_DEBUG_CATEGORY_INIT (gst_tidmaivideosink_debug, "TIDmaiVideoSink", 0, "TIDmaiVideoSink Element");
	GST_BOILERPLATE_FULL (GstTIDmaiVideoSink, gst_tidmaivideosink, GstVideoSink, GST_TYPE_VIDEO_SINK, _do_init);

- In my .h code I am doing the following
	- Define a member GstVideoSink videosink as the first member of my GstTIDmaiVideoSink structure
	- Define a member GstVideoSinkClass parent_class as the first member of my GstTIDmaiVideoSinkClass structure

Lastly, in my makefile I am adding $(GST_BASE_LIBS), $(GST_PLUGINS_BASE_LIBS) and -lgstvideo-0.10 to my LIBADD variable.

Even with all of this I don't seem to be getting the lateness property set correctly.  I ran the compile of my plugin and stopped after the pre-processor to see what the GST_BOILERPLATE_FULL macro was expanding out to.  I see the following output:

static void gst_tidmaivideosink_base_init (gpointer g_class);
static void gst_tidmaivideosink_class_init (GstTIDmaiVideoSinkClass *g_class);
static void gst_tidmaivideosink_init (GstTIDmaiVideoSink *object, GstTIDmaiVideoSinkClass *g_class);
static GstVideoSinkClass *parent_class = ((void *)0); 
static void gst_tidmaivideosink_class_init_trampoline (gpointer g_class, gpointer data) {
  parent_class = (GstVideoSinkClass *) g_type_class_peek_parent (g_class);
  gst_tidmaivideosink_class_init ((GstTIDmaiVideoSinkClass *)g_class);
}
GType gst_tidmaivideosink_get_type (void);
GType gst_tidmaivideosink_get_type (void) { 
  static GType object_type = 0;
  if ((__builtin_expect (__extension__ ({ int _g_boolean_var_; if (object_type == 0) _g_boolean_var_ = 1; else _g_boolean_var_ = 0; _g_boolean_var_; }), 0))) { 
    static const GTypeInfo object_info = { sizeof (GstTIDmaiVideoSinkClass), gst_tidmaivideosink_base_init, ((void *)0), gst_tidmaivideosink_class_init_trampoline, ((void *)0), ((void *)0), sizeof (GstTIDmaiVideoSink), 0, (GInstanceInitFunc) gst_tidmaivideosink_init };
  object_type = g_type_register_static ((gst_video_sink_get_type()), "GstTIDmaiVideoSink", &object_info, (GTypeFlags) 0);
 (void) __extension__ ({ if (gst_tidmaivideosink_debug == ((void *)0)) gst_tidmaivideosink_debug = _gst_debug_category_new ("TIDmaiVideoSink",0,"TIDmaiVideoSink Element"); });; } return object_type; };

Notice that object_type is being set to use gst_video_sink_get_type() for the parent class.

Can anyone please tell me what I am missing about inheriting from the VideoSink class and why I don't seem to be getting the default max_lateness behavior that the VideoSink class defines.  I will provide full source code if needed but I didn't want to make this e-mail too ugly to begin.

Sincerely,
Chase Maupin
Software Applications
Catalog DSP Products
e-mail: chase.maupin at ti.com