That should be reviewed by someone who keeps track of what's going on in winegstreamer transform, and I think that's @rbernon himself. I have a quick question regarding changes here, what's the idea behind have a copier internally? Is it for the case when downstream node does not provide d3d samples? I'm not entirely sure how this is resolved on windows, I know that this happens:
source -> unware-mft -> evr ==> source -> unaware-mft -> copier -> evr
Then, if you have:
source-> aware-mft -> evr ==> does that use just one allocator from evr, or mft provides another one?
and in any case, does it get resolved to:
source -> copier -> aware-mft -> evr?
Source in general can support allocators I think, but there is a special API for those, and regular media formats sources don't have that.