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Subject: Re: [PATCH v1 7/9] media: verisilicon: Add Rockchip AV1 decoder
From:   Daniel Almeida <daniel.almeida@collabora.com>
To:     Benjamin Gaignard <benjamin.gaignard@collabora.com>,
        Nicolas Dufresne <nicolas@ndufresne.ca>,
        ezequiel@vanguardiasur.com.ar, p.zabel@pengutronix.de,
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        nicolas.dufresne@collabora.co.uk
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        devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
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Date:   Fri, 23 Dec 2022 20:15:38 -0300
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> > +	int cur_offset[V4L2_AV1_NUM_REF_FRAMES - 1];
> > +	int cur_roffset[V4L2_AV1_NUM_REF_FRAMES - 1];
>=20
> 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.=20

-- Daniel