videoaggregator: Don't require any pads to be configured for negotiat…

…ing source pad caps

This is not actually required (anymore?). Source pad caps can be
negotiated at any time regardless of any configured (or existing) sink
pads and videoaggregator comes up with some fixated caps based on the
downstream caps.

Subclasses can override this behaviour as needed by overriding
update_src_caps().

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-base/-/merge_requests/848>

gst-libs/gst/video/gstvideoaggregator.c

@@ -981,29 +981,6 @@ gst_video_aggregator_default_update_src_caps (GstAggregator * agg,
 {
   GstVideoAggregatorClass *vagg_klass = GST_VIDEO_AGGREGATOR_GET_CLASS (agg);
   GstVideoAggregator *vagg = GST_VIDEO_AGGREGATOR (agg);
-  gboolean at_least_one_pad_configured = FALSE;
-  GList *l;
-
-  GST_OBJECT_LOCK (vagg);
-  for (l = GST_ELEMENT (vagg)->sinkpads; l; l = l->next) {
-    GstVideoAggregatorPad *mpad = l->data;
-
-    if (GST_VIDEO_INFO_WIDTH (&mpad->info) == 0
-        || GST_VIDEO_INFO_HEIGHT (&mpad->info) == 0)
-      continue;
-
-    at_least_one_pad_configured = TRUE;
-  }
-  GST_OBJECT_UNLOCK (vagg);
-
-  if (!at_least_one_pad_configured) {
-    /* We couldn't decide the output video info because the sinkpads don't have
-     * all the caps yet, so we mark the pad as needing a reconfigure. This
-     * allows aggregate() to skip ahead a bit and try again later. */
-    GST_DEBUG_OBJECT (vagg, "Couldn't decide output video info");
-    gst_pad_mark_reconfigure (agg->srcpad);
-    return GST_AGGREGATOR_FLOW_NEED_DATA;
-  }
 
   g_assert (vagg_klass->update_caps);