Re: [PATCH v1 7/9] media: verisilicon: Add Rockchip AV1 decoder

[Daniel Almeida]

Ah, I was too quick on that answer :/

I see that they have REFS_PER_FRAME (7), TOTAL_REFS_PER_FRAME (8) _and_
NUM_REF_FRAMES (8), in which case it is redundant indeed. I will remove
that on v4.

-- Daniel

On Fri, 2022-12-23 at 20:15 -0300, Daniel Almeida wrote:
> > > +       int cur_offset[V4L2_AV1_NUM_REF_FRAMES - 1];
> > > +       int cur_roffset[V4L2_AV1_NUM_REF_FRAMES - 1];
> > 
> > This looks like V4L2_AV1_REFS_PER_FRAME. Daniel, should be remove
> > this
> > V4L2_AV1_NUM_REF_FRAMES ? Its redundant with
> > V4L2_AV1_TOTAL_REFS_PER_FRAME ...
> 
> Hi. These are different. NUM_REF_FRAMES is the size of the "DPB"
> while
> TOTAL_REFS_PER_FRAME is the maximum number of references a frame can
> use. It just so happens that in AV1 these two are close in absolute
> value (i.e. 7 vs 8).
> 
> Using VP9 as a comparison, the DPB size is still 8, but
> REFS_PER_FRAME
> is 3 (meaning a frame can specificy LAST, GOLDEN and ALTREF values).
> 
> As this is per spec and a mere convenience, I vote for keeping it. 
> 
> -- Daniel