Something

/* mark buffers and put on caps */
caps = gst_caps_new_simply ("video/x-theora", 
   "width", G_TYPE_INT, enc->width, 
   "height", G_TYPE_INT, enc->height, 
   "framerate", GST_TYPE_FRACTION, enc->fps_n, enc->fps_d, 
   "pixel-aspect-ratio", GST_TYPE_FRACTION, enc->par_n, enc->par_d,
   NULL);
caps = theora_set_header_on_caps (caps, buffers);
GST_DEBUG ("here are the caps: %" GST_PTR_FORMAT, caps);
gst_pad_set_caps (enc->srcpad, caps);