Gets the capabilities of the peer connected to this pad. Similar to
gst_pad_query_caps().
When called on srcpads @filter contains the caps that
upstream could produce in the order preferred by upstream. When
called on sinkpads @filter contains the caps accepted by
downstream in the preferred order. @filter might be %NULL but
if it is not %NULL the returned caps will be a subset of @filter.
Gets the capabilities of the peer connected to this pad. Similar to gst_pad_query_caps().
When called on srcpads @filter contains the caps that upstream could produce in the order preferred by upstream. When called on sinkpads @filter contains the caps accepted by downstream in the preferred order. @filter might be %NULL but if it is not %NULL the returned caps will be a subset of @filter.