Re: [PATCH 02/12] media: hantro: Do not reorder H264 scaling list

[Ezequiel Garcia <ezequiel@collabora.com>]

Hi Jonas,

Thanks for your patch.

On Mon, 2019-09-02 at 16:18 +0000, Jonas Karlman wrote:
[..]
> 
> > > diff --git a/drivers/staging/media/hantro/hantro_h264.c b/drivers/staging/media/hantro/hantro_h264.c
> > > index 0d758e0c0f99..e2d01145ac4f 100644
> > > --- a/drivers/staging/media/hantro/hantro_h264.c
> > > +++ b/drivers/staging/media/hantro/hantro_h264.c
> > > @@ -20,7 +20,7 @@
> > >  /* Size with u32 units. */
> > >  #define CABAC_INIT_BUFFER_SIZE		(460 * 2)
> > >  #define POC_BUFFER_SIZE			34
> > > -#define SCALING_LIST_SIZE		(6 * 16 + 6 * 64)
> > > +#define SCALING_LIST_SIZE		(6 * 16 + 2 * 64)
> > This changes the size of struct hantro_h264_dec_priv_tbl. Did this
> > describe the auxiliary buffer format incorrectly before?
> 
> Based on RKMPP and Hantro SDK the HW expects the 8x8 inter/intra list for
> Y-component to be located at indices 0 and 1, lists for Cr/Cb is only used for
> 4:4:4 and HW only supports 4:0:0/4:2:0 if I am not mistaken. So the unused
> extra 4 lists at the end of the auxiliary buffer seemed like a waste,
> also RKMPP and Hantro SDK only seemed to allocate space for 2 lists.
> 

I think it would make a lot of sense to document what the hardware
expects somewhere, perhaps as part of the struct hantro_h264_dec_priv_tbl
documentation?

Thanks,
Ezequiel