On Wed, 26 Jun 2019 13:33:41 +0200 Paul Kocialkowski <paul.kocialkowski@xxxxxxxxxxx> wrote: > Hi, > > On Mon, 2019-06-10 at 10:52 +0200, Boris Brezillon wrote: > > Those lists can be extracted from the dpb, let's simplify userspace > > life and build that list kernel-side (generic helpers will be provided > > for drivers that need this list). > > I don't really have any clear idea about that, but there was a > discussion about DPB vs reference picture lists some weeks ago. What we call DPB right now is actually a list of reference pictures (each entry being flagged long or short term). When reading the spec, you said DPB was referring to something that's more implementation specific, and I think that's what motivated your initial suggestion to rename this field into something more appropriate (ref_pics?). TBH, I'm just guessing here, since you were the one initially proposing this change, and I must say that having to explain what you had in mind at that time is a bit weird :P. > > Is there some mail thread with a rationale about it, some IRC logs I > could look at or could the people involved in the discussion provide > some additional background at this point? Well, you were part of the discussion, and I think most of it happened in the "Proposed updates and guidelines for MPEG-2, H.264 and H.265 stateless support" thread you started. > > IIRC we also talked about removing the DPB or at least renaming it, but > I don't have a clear idea of the outcome as well. The list of long/short refs has to be passed, and that's actually what we currently call "DPB", so we're just talking about a rename here, nothing more. The ordered P/B0/B1 reflists can easily be built from the un-ordered list of ref pics, so I'm just proposing to get rid of these fields and have a generic implementation kernel-side so that drivers that need it don't have to re-implement it.
