Re: [PATCH 2/9] media: v4l2: Add NV12_16L16 pixel format to v4l2 format info

[Nicolas Dufresne]

Le samedi 25 mars 2023 à 23:01 +0200, Laurent Pinchart a écrit :
> Hi Paul,
> 
> Thank you for the patch.
> 
> On Fri, Mar 24, 2023 at 04:12:21PM +0100, Paul Kocialkowski wrote:
> > Represent the NV12_16L16 pixel format in the v4l2 format info table.
> > This is a 16x16 tiled version of NV12.
> > 
> > Signed-off-by: Paul Kocialkowski <paul.kocialkowski@xxxxxxxxxxx>
> > ---
> >  drivers/media/v4l2-core/v4l2-common.c | 2 ++
> >  1 file changed, 2 insertions(+)
> > 
> > diff --git a/drivers/media/v4l2-core/v4l2-common.c b/drivers/media/v4l2-core/v4l2-common.c
> > index 3d044b31caad..5101989716aa 100644
> > --- a/drivers/media/v4l2-core/v4l2-common.c
> > +++ b/drivers/media/v4l2-core/v4l2-common.c
> > @@ -280,6 +280,8 @@ const struct v4l2_format_info *v4l2_format_info(u32 format)
> >  		/* Tiled YUV formats */
> >  		{ .format = V4L2_PIX_FMT_NV12_4L4, .pixel_enc = V4L2_PIXEL_ENC_YUV, .mem_planes = 1, .comp_planes = 2, .bpp = { 1, 2, 0, 0 }, .hdiv = 2, .vdiv = 2 },
> >  		{ .format = V4L2_PIX_FMT_P010_4L4, .pixel_enc = V4L2_PIXEL_ENC_YUV, .mem_planes = 1, .comp_planes = 2, .bpp = { 2, 4, 0, 0 }, .hdiv = 2, .vdiv = 2 },
> > +		{ .format = V4L2_PIX_FMT_NV12_16L16,	.pixel_enc = V4L2_PIXEL_ENC_YUV, .mem_planes = 1, .comp_planes = 2, .bpp = { 1, 2, 0, 0 }, .hdiv = 2, .vdiv = 2,
> > +		  .block_w = { 16, 16, 0, 0 }, .block_h = { 16, 16, 0, 0 } },
> 
> Not necessarily related to this patch, but I'm a bit puzzled by why
> V4L2_PIX_FMT_NV12_4L4 doesn't list block sizes.

It looks like Ezequiel introduced that initially, but didn't introduce any tiled
format, as a side effect, we missed it and no one ever used it.

In practice, its not dramatic, since most of the time, the alignment needed is
bigger then the block (specially with only 4x4 tiles), but we should certainly
fix that, thanks for spotting.

> 
> >  
> >  		/* YUV planar formats, non contiguous variant */
> >  		{ .format = V4L2_PIX_FMT_YUV420M, .pixel_enc = V4L2_PIXEL_ENC_YUV, .mem_planes = 3, .comp_planes = 3, .bpp = { 1, 1, 1, 0 }, .hdiv = 2, .vdiv = 2 },
>