Could we reuse the allocation in set_format of overlay elements ?
Basically we receiver caps, and do an allocation query in order to influence the caps. Sebastien is asking if we can cache this query in order to pass this back without recursing when / if upstream makes an allocation query later. Note that this is a very tricky thing to cache, since download pipeline may have been changed meanwhile.
The following discussion from !436 (merged) should be addressed: