Re: [PATCH v3 3/3] media: rkvdec: Add the VP9 backend

[Ezequiel Garcia <ezequiel@collabora.com>]

On Fri, 2020-05-08 at 12:34 +0200, Hans Verkuil wrote:
> On 05/05/2020 15:41, Ezequiel Garcia wrote:
> > From: Boris Brezillon <boris.brezillon@collabora.com>
> > 
> > The Rockchip VDEC supports VP9 profile 0 up to 4096x2304@30fps. Add
> > a backend for this new format.
> > 
> > Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
> > Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
> > ---
> >  drivers/staging/media/rkvdec/Makefile     |    2 +-
> >  drivers/staging/media/rkvdec/rkvdec-vp9.c | 1577 +++++++++++++++++++++
> >  drivers/staging/media/rkvdec/rkvdec.c     |   56 +-
> >  drivers/staging/media/rkvdec/rkvdec.h     |    6 +
> >  4 files changed, 1637 insertions(+), 4 deletions(-)
> >  create mode 100644 drivers/staging/media/rkvdec/rkvdec-vp9.c
> > 
> > diff --git a/drivers/staging/media/rkvdec/Makefile b/drivers/staging/media/rkvdec/Makefile
> > index c08fed0a39f9..cb86b429cfaa 100644
> > --- a/drivers/staging/media/rkvdec/Makefile
> > +++ b/drivers/staging/media/rkvdec/Makefile
> > @@ -1,3 +1,3 @@
> >  obj-$(CONFIG_VIDEO_ROCKCHIP_VDEC) += rockchip-vdec.o
> >  
> > -rockchip-vdec-y += rkvdec.o rkvdec-h264.o
> > +rockchip-vdec-y += rkvdec.o rkvdec-h264.o rkvdec-vp9.o
> > diff --git a/drivers/staging/media/rkvdec/rkvdec-vp9.c b/drivers/staging/media/rkvdec/rkvdec-vp9.c
> > new file mode 100644
> > index 000000000000..37d0ea4e3570
> > --- /dev/null
> > +++ b/drivers/staging/media/rkvdec/rkvdec-vp9.c
> > @@ -0,0 +1,1577 @@
> 
> <snip>
> 
> > +static void init_inter_probs(struct rkvdec_ctx *ctx,
> > +			     const struct rkvdec_vp9_run *run)
> > +{
> > +	const struct v4l2_ctrl_vp9_frame_decode_params *dec_params;
> > +	struct rkvdec_vp9_ctx *vp9_ctx = ctx->priv;
> > +	struct rkvdec_vp9_priv_tbl *tbl = vp9_ctx->priv_tbl.cpu;
> > +	struct rkvdec_vp9_inter_frame_probs *rkprobs;
> > +	const struct v4l2_vp9_probabilities *probs;
> > +	unsigned int i, j, k;
> > +
> > +	rkprobs = &tbl->probs.inter;
> > +	dec_params = run->decode_params;
> > +	probs = &dec_params->probs;
> > +
> > +	/*
> > +	 * inter probs
> > +	 * 151 x 128 bits, aligned to 152 x 128 bits
> > +	 * inter only
> > +	 * intra_y_mode & inter_block info 6 x 128 bits
> > +	 */
> > +
> > +	memcpy(rkprobs->y_mode, probs->y_mode, sizeof(rkprobs->y_mode));
> > +	memcpy(rkprobs->comp_mode, probs->comp_mode,
> > +	       sizeof(rkprobs->comp_mode));
> > +	memcpy(rkprobs->comp_ref, probs->comp_ref,
> > +	       sizeof(rkprobs->comp_ref));
> > +	memcpy(rkprobs->single_ref, probs->single_ref,
> > +	       sizeof(rkprobs->single_ref));
> > +	memcpy(rkprobs->inter_mode, probs->inter_mode,
> > +	       sizeof(rkprobs->inter_mode));
> > +	memcpy(rkprobs->interp_filter, probs->interp_filter,
> > +	       sizeof(rkprobs->interp_filter));
> > +
> > +	/* 128 x 128 bits coeff related */
> > +	for (i = 0; i < ARRAY_SIZE(probs->coef); i++) {
> > +		for (j = 0; j < ARRAY_SIZE(probs->coef[0]); j++) {
> > +			for (k = 0; k < ARRAY_SIZE(probs->coef[0][0]); k++)
> > +				write_coeff_plane(probs->coef[i][j][k],
> > +						  rkprobs->coef[k][i][j]);
> > +		}
> > +	}
> > +
> > +	/* intra uv mode 6 x 128 */
> > +	memcpy(rkprobs->uv_mode_0_2, &probs->uv_mode[0],
> > +	       sizeof(rkprobs->uv_mode_0_2));
> > +	memcpy(rkprobs->uv_mode_3_5, &probs->uv_mode[3],
> > +	       sizeof(rkprobs->uv_mode_3_5));
> > +	memcpy(rkprobs->uv_mode_6_8, &probs->uv_mode[6],
> > +	       sizeof(rkprobs->uv_mode_6_8));
> > +	memcpy(rkprobs->uv_mode_9, &probs->uv_mode[9],
> > +	       sizeof(rkprobs->uv_mode_9));
> > +
> > +	/* mv related 6 x 128 */
> > +	memcpy(rkprobs->mv.joint, probs->mv.joint,
> > +	       sizeof(rkprobs->mv.joint));
> > +	memcpy(rkprobs->mv.sign, probs->mv.sign,
> > +	       sizeof(rkprobs->mv.sign));
> > +	memcpy(rkprobs->mv.class, probs->mv.class,
> > +	       sizeof(rkprobs->mv.class));
> > +	memcpy(rkprobs->mv.class0_bit, probs->mv.class0_bit,
> > +	       sizeof(rkprobs->mv.class0_bit));
> > +	memcpy(rkprobs->mv.bits, probs->mv.bits,
> > +	       sizeof(rkprobs->mv.bits));
> > +	memcpy(rkprobs->mv.class0_fr, probs->mv.class0_fr,
> > +	       sizeof(rkprobs->mv.class0_fr));
> > +	memcpy(rkprobs->mv.fr, probs->mv.fr,
> > +	       sizeof(rkprobs->mv.fr));
> > +	memcpy(rkprobs->mv.class0_hp, probs->mv.class0_hp,
> > +	       sizeof(rkprobs->mv.class0_hp));
> > +	memcpy(rkprobs->mv.hp, probs->mv.hp,
> > +	       sizeof(rkprobs->mv.hp));
> 
> Can't you just do: 'rkprobs->mv = probs->mv'?
> 

I think I'd like to keep this as-is.

Having the memcpy makes it explicit that we are copying
these structs around. While the assignment would
bring type checking, it can be misleading for readers.

Thanks,
Ezequiel