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Message-ID: <f3f8749e30aad81bc39ed9b60cd308ac5f3c6707.camel@ndufresne.ca>
Subject: Re: [RFC PATCH 18/20] lib: image-formats: Add v4l2 formats support
From:   Nicolas Dufresne <nicolas@ndufresne.ca>
To:     Ville =?ISO-8859-1?Q?Syrj=E4l=E4?= <ville.syrjala@linux.intel.com>
Cc:     Maxime Ripard <maxime.ripard@bootlin.com>,
        Daniel Vetter <daniel.vetter@intel.com>,
        David Airlie <airlied@linux.ie>,
        Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
        Sean Paul <seanpaul@chromium.org>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        Sakari Ailus <sakari.ailus@linux.intel.com>,
        linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org,
        Paul Kocialkowski <paul.kocialkowski@bootlin.com>,
        Hans Verkuil <hans.verkuil@cisco.com>,
        Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
        Thomas Petazzoni <thomas.petazzoni@bootlin.com>,
        linux-media@vger.kernel.org, Daniel Stone <daniels@collabora.com>
Date:   Wed, 20 Mar 2019 12:30:25 -0400
In-Reply-To: <20190320160939.GR3888@intel.com>
References: <cover.92acdec88ee4c280cb74e08ea22f0075e5fa055c.1553032382.git-series.maxime.ripard@bootlin.com>
         <c97024b97d3261dcf41aad3c8bc1c5d9906f33c9.1553032382.git-series.maxime.ripard@bootlin.com>
         <d8f4a31e35b1702230ced4a0cb43c10d1c7e60c8.camel@ndufresne.ca>
         <20190320142739.GK3888@intel.com>
         <a13f7fdeaf1a5e97f21a6048da765705b59d64c2.camel@ndufresne.ca>
         <20190320160939.GR3888@intel.com>
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Le mercredi 20 mars 2019 =C3=A0 18:09 +0200, Ville Syrj=C3=A4l=C3=A4 a =C3=
=A9crit :
> On Wed, Mar 20, 2019 at 11:51:58AM -0400, Nicolas Dufresne wrote:
> > Le mercredi 20 mars 2019 =C3=A0 16:27 +0200, Ville Syrj=C3=A4l=C3=A4 a =
=C3=A9crit :
> > > On Tue, Mar 19, 2019 at 07:29:18PM -0400, Nicolas Dufresne wrote:
> > > > Le mardi 19 mars 2019 =C3=A0 22:57 +0100, Maxime Ripard a =C3=A9cri=
t :
> > > > > V4L2 uses different fourcc's than DRM, and has a different set of=
 formats.
> > > > > For now, let's add the v4l2 fourcc's for the already existing for=
mats.
> > > > >=20
> > > > > Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
> > > > > ---
> > > > >  include/linux/image-formats.h |  9 +++++-
> > > > >  lib/image-formats.c           | 67 +++++++++++++++++++++++++++++=
+++++++-
> > > > >  2 files changed, 76 insertions(+)
> > > > >=20
> > > > > diff --git a/include/linux/image-formats.h b/include/linux/image-=
formats.h
> > > > > index 53fd73a71b3d..fbc3a4501ebd 100644
> > > > > --- a/include/linux/image-formats.h
> > > > > +++ b/include/linux/image-formats.h
> > > > > @@ -26,6 +26,13 @@ struct image_format_info {
> > > > >  	};
> > > > > =20
> > > > >  	/**
> > > > > +	 * @v4l2_fmt:
> > > > > +	 *
> > > > > +	 * V4L2 4CC format identifier (V4L2_PIX_FMT_*)
> > > > > +	 */
> > > > > +	u32 v4l2_fmt;
> > > > > +
> > > > > +	/**
> > > > >  	 * @depth:
> > > > >  	 *
> > > > >  	 * Color depth (number of bits per pixel excluding padding bits=
),
> > > > > @@ -222,6 +229,8 @@ image_format_info_is_yuv_sampling_444(const s=
truct image_format_info *info)
> > > > > =20
> > > > >  const struct image_format_info *__image_format_drm_lookup(u32 dr=
m);
> > > > >  const struct image_format_info *image_format_drm_lookup(u32 drm)=
;
> > > > > +const struct image_format_info *__image_format_v4l2_lookup(u32 v=
4l2);
> > > > > +const struct image_format_info *image_format_v4l2_lookup(u32 v4l=
2);
> > > > >  unsigned int image_format_plane_cpp(const struct image_format_in=
fo *format,
> > > > >  				    int plane);
> > > > >  unsigned int image_format_plane_width(int width,
> > > > > diff --git a/lib/image-formats.c b/lib/image-formats.c
> > > > > index 9b9a73220c5d..39f1d38ae861 100644
> > > > > --- a/lib/image-formats.c
> > > > > +++ b/lib/image-formats.c
> > > > > @@ -8,6 +8,7 @@
> > > > >  static const struct image_format_info formats[] =3D {
> > > > >  	{
> > > > >  		.drm_fmt =3D DRM_FORMAT_C8,
> > > > > +		.v4l2_fmt =3D V4L2_PIX_FMT_GREY,
> > > > >  		.depth =3D 8,
> > > > >  		.num_planes =3D 1,
> > > > >  		.cpp =3D { 1, 0, 0 },
> > > > > @@ -15,6 +16,7 @@ static const struct image_format_info formats[]=
 =3D {
> > > > >  		.vsub =3D 1,
> > > > >  	}, {
> > > > >  		.drm_fmt =3D DRM_FORMAT_RGB332,
> > > > > +		.v4l2_fmt =3D V4L2_PIX_FMT_RGB332,
> > > > >  		.depth =3D 8,
> > > > >  		.num_planes =3D 1,
> > > > >  		.cpp =3D { 1, 0, 0 },
> > > > > @@ -29,6 +31,7 @@ static const struct image_format_info formats[]=
 =3D {
> > > > >  		.vsub =3D 1,
> > > > >  	}, {
> > > > >  		.drm_fmt =3D DRM_FORMAT_XRGB4444,
> > > > > +		.v4l2_fmt =3D V4L2_PIX_FMT_XRGB444,
> > > > >  		.depth =3D 0,
> > > > >  		.num_planes =3D 1,
> > > > >  		.cpp =3D { 2, 0, 0 },
> > > > > @@ -57,6 +60,7 @@ static const struct image_format_info formats[]=
 =3D {
> > > > >  		.vsub =3D 1,
> > > > >  	}, {
> > > > >  		.drm_fmt =3D DRM_FORMAT_ARGB4444,
> > > > > +		.v4l2_fmt =3D V4L2_PIX_FMT_ARGB444,
> > > > >  		.depth =3D 0,
> > > > >  		.num_planes =3D 1,
> > > > >  		.cpp =3D { 2, 0, 0 },
> > > > > @@ -89,6 +93,7 @@ static const struct image_format_info formats[]=
 =3D {
> > > > >  		.has_alpha =3D true,
> > > > >  	}, {
> > > > >  		.drm_fmt =3D DRM_FORMAT_XRGB1555,
> > > > > +		.v4l2_fmt =3D V4L2_PIX_FMT_XRGB555,
> > > > >  		.depth =3D 15,
> > > > >  		.num_planes =3D 1,
> > > > >  		.cpp =3D { 2, 0, 0 },
> > > > > @@ -117,6 +122,7 @@ static const struct image_format_info formats=
[] =3D {
> > > > >  		.vsub =3D 1,
> > > > >  	}, {
> > > > >  		.drm_fmt =3D DRM_FORMAT_ARGB1555,
> > > > > +		.v4l2_fmt =3D V4L2_PIX_FMT_ARGB555,
> > > > >  		.depth =3D 15,
> > > > >  		.num_planes =3D 1,
> > > > >  		.cpp =3D { 2, 0, 0 },
> > > > > @@ -149,6 +155,7 @@ static const struct image_format_info formats=
[] =3D {
> > > > >  		.has_alpha =3D true,
> > > > >  	}, {
> > > > >  		.drm_fmt =3D DRM_FORMAT_RGB565,
> > > > > +		.v4l2_fmt =3D V4L2_PIX_FMT_RGB565,
> > > > >  		.depth =3D 16,
> > > > >  		.num_planes =3D 1,
> > > > >  		.cpp =3D { 2, 0, 0 },
> > > > > @@ -163,6 +170,7 @@ static const struct image_format_info formats=
[] =3D {
> > > > >  		.vsub =3D 1,
> > > > >  	}, {
> > > > >  		.drm_fmt =3D DRM_FORMAT_RGB888,
> > > > > +		.v4l2_fmt =3D V4L2_PIX_FMT_RGB24,
> > > > >  		.depth =3D 24,
> > > > >  		.num_planes =3D 1,
> > > > >  		.cpp =3D { 3, 0, 0 },
> > > > > @@ -170,6 +178,7 @@ static const struct image_format_info formats=
[] =3D {
> > > > >  		.vsub =3D 1,
> > > > >  	}, {
> > > > >  		.drm_fmt =3D DRM_FORMAT_BGR888,
> > > > > +		.v4l2_fmt =3D V4L2_PIX_FMT_BGR24,
> > > > >  		.depth =3D 24,
> > > > >  		.num_planes =3D 1,
> > > > >  		.cpp =3D { 3, 0, 0 },
> > > > > @@ -177,6 +186,7 @@ static const struct image_format_info formats=
[] =3D {
> > > > >  		.vsub =3D 1,
> > > > >  	}, {
> > > > >  		.drm_fmt =3D DRM_FORMAT_XRGB8888,
> > > > > +		.v4l2_fmt =3D V4L2_PIX_FMT_XRGB32,
> > > >=20
> > > > All RGB mapping should be surrounded by ifdef, because many (not al=
l)
> > > > DRM formats represent the order of component when placed in a CPU
> > > > register, unlike V4L2 which uses memory order. I've pick this one
> > >=20
> > > DRM formats are explicitly defined as little endian.
> >=20
> > Yes, that means the same thing. The mapping has nothing to do with the
> > buffer bytes order, unlike V4L2 (and most streaming stack) do.
>=20
> It has everything to do with byte order. Little endian means the least
> significant byte is stored in the first byte in memory.
>=20
> Based on https://www.kernel.org/doc/html/v4.15/media/uapi/v4l/pixfmt-pack=
ed-rgb.html
> drm XRGB888 is actually v4l XBGR32, not XRGB32 as claimed by this patch.

That's basically what I said, as it's define for Little Endian rather
then buffer order, you have to make the mapping conditional. It
basically mean that in memory, the DRM format physically differ
depending on CPU endian. Last time we have run this on PPC / Big
Endian, the mapping was XRGB/XRGB, we checked that up multiple time
with the DRM maintainers and was told this is exactly what it's suppose
to do, hence this endian dependant mapping all over the place. If you
make up that this isn't right, you are breaking userspace, and people
don't like that.

So the mapping should be:
Little: DRM XRGB / V4L2 XBGR
Big:    DRM XRGB / V4L2 XRGB

>=20
> > > > randomly, but this one on most system, little endian, will match
> > > > V4L2_PIX_FMT_XBGR32. This type of complex mapping can be found in
> > > > multiple places, notably in GStreamer:
> > > >=20
> > > > https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/blob/maste=
r/sys/kms/gstkmsutils.c#L45
> > > >=20
> > > > >  		.depth =3D 24,
> > > > >  		.num_planes =3D 1,
> > > > >  		.cpp =3D { 4, 0, 0 },
> > > > > @@ -281,6 +291,7 @@ static const struct image_format_info formats=
[] =3D {
> > > > >  		.has_alpha =3D true,
> > > > >  	}, {
> > > > >  		.drm_fmt =3D DRM_FORMAT_ARGB8888,
> > > > > +		.v4l2_fmt =3D V4L2_PIX_FMT_ARGB32,
> > > > >  		.depth =3D 32,
> > > > >  		.num_planes =3D 1,
> > > > >  		.cpp =3D { 4, 0, 0 },
> > > > > @@ -361,6 +372,7 @@ static const struct image_format_info formats=
[] =3D {
> > > > >  		.has_alpha =3D true,
> > > > >  	}, {
> > > > >  		.drm_fmt =3D DRM_FORMAT_YUV410,
> > > > > +		.v4l2_fmt =3D V4L2_PIX_FMT_YUV410,
> > > > >  		.depth =3D 0,
> > > > >  		.num_planes =3D 3,
> > > > >  		.cpp =3D { 1, 1, 1 },
> > > > > @@ -369,6 +381,7 @@ static const struct image_format_info formats=
[] =3D {
> > > > >  		.is_yuv =3D true,
> > > > >  	}, {
> > > > >  		.drm_fmt =3D DRM_FORMAT_YVU410,
> > > > > +		.v4l2_fmt =3D V4L2_PIX_FMT_YVU410,
> > > > >  		.depth =3D 0,
> > > > >  		.num_planes =3D 3,
> > > > >  		.cpp =3D { 1, 1, 1 },
> > > > > @@ -393,6 +406,7 @@ static const struct image_format_info formats=
[] =3D {
> > > > >  		.is_yuv =3D true,
> > > > >  	}, {
> > > > >  		.drm_fmt =3D DRM_FORMAT_YUV420,
> > > > > +		.v4l2_fmt =3D V4L2_PIX_FMT_YUV420M,
> > > > >  		.depth =3D 0,
> > > > >  		.num_planes =3D 3,
> > > > >  		.cpp =3D { 1, 1, 1 },
> > > > > @@ -401,6 +415,7 @@ static const struct image_format_info formats=
[] =3D {
> > > > >  		.is_yuv =3D true,
> > > > >  	}, {
> > > > >  		.drm_fmt =3D DRM_FORMAT_YVU420,
> > > > > +		.v4l2_fmt =3D V4L2_PIX_FMT_YVU420M,
> > > > >  		.depth =3D 0,
> > > > >  		.num_planes =3D 3,
> > > > >  		.cpp =3D { 1, 1, 1 },
> > > > > @@ -409,6 +424,7 @@ static const struct image_format_info formats=
[] =3D {
> > > > >  		.is_yuv =3D true,
> > > > >  	}, {
> > > > >  		.drm_fmt =3D DRM_FORMAT_YUV422,
> > > > > +		.v4l2_fmt =3D V4L2_PIX_FMT_YUV422M,
> > > > >  		.depth =3D 0,
> > > > >  		.num_planes =3D 3,
> > > > >  		.cpp =3D { 1, 1, 1 },
> > > > > @@ -417,6 +433,7 @@ static const struct image_format_info formats=
[] =3D {
> > > > >  		.is_yuv =3D true,
> > > > >  	}, {
> > > > >  		.drm_fmt =3D DRM_FORMAT_YVU422,
> > > > > +		.v4l2_fmt =3D V4L2_PIX_FMT_YVU422M,
> > > > >  		.depth =3D 0,
> > > > >  		.num_planes =3D 3,
> > > > >  		.cpp =3D { 1, 1, 1 },
> > > > > @@ -425,6 +442,7 @@ static const struct image_format_info formats=
[] =3D {
> > > > >  		.is_yuv =3D true,
> > > > >  	}, {
> > > > >  		.drm_fmt =3D DRM_FORMAT_YUV444,
> > > > > +		.v4l2_fmt =3D V4L2_PIX_FMT_YUV444M,
> > > > >  		.depth =3D 0,
> > > > >  		.num_planes =3D 3,
> > > > >  		.cpp =3D { 1, 1, 1 },
> > > > > @@ -433,6 +451,7 @@ static const struct image_format_info formats=
[] =3D {
> > > > >  		.is_yuv =3D true,
> > > > >  	}, {
> > > > >  		.drm_fmt =3D DRM_FORMAT_YVU444,
> > > > > +		.v4l2_fmt =3D V4L2_PIX_FMT_YVU444M,
> > > > >  		.depth =3D 0,
> > > > >  		.num_planes =3D 3,
> > > > >  		.cpp =3D { 1, 1, 1 },
> > > > > @@ -441,6 +460,7 @@ static const struct image_format_info formats=
[] =3D {
> > > > >  		.is_yuv =3D true,
> > > > >  	}, {
> > > > >  		.drm_fmt =3D DRM_FORMAT_NV12,
> > > > > +		.v4l2_fmt =3D V4L2_PIX_FMT_NV12,
> > > > >  		.depth =3D 0,
> > > > >  		.num_planes =3D 2,
> > > > >  		.cpp =3D { 1, 2, 0 },
> > > > > @@ -449,6 +469,7 @@ static const struct image_format_info formats=
[] =3D {
> > > > >  		.is_yuv =3D true,
> > > > >  	}, {
> > > > >  		.drm_fmt =3D DRM_FORMAT_NV21,
> > > > > +		.v4l2_fmt =3D V4L2_PIX_FMT_NV21,
> > > > >  		.depth =3D 0,
> > > > >  		.num_planes =3D 2,
> > > > >  		.cpp =3D { 1, 2, 0 },
> > > > > @@ -457,6 +478,7 @@ static const struct image_format_info formats=
[] =3D {
> > > > >  		.is_yuv =3D true,
> > > > >  	}, {
> > > > >  		.drm_fmt =3D DRM_FORMAT_NV16,
> > > > > +		.v4l2_fmt =3D V4L2_PIX_FMT_NV16,
> > > > >  		.depth =3D 0,
> > > > >  		.num_planes =3D 2,
> > > > >  		.cpp =3D { 1, 2, 0 },
> > > > > @@ -465,6 +487,7 @@ static const struct image_format_info formats=
[] =3D {
> > > > >  		.is_yuv =3D true,
> > > > >  	}, {
> > > > >  		.drm_fmt =3D DRM_FORMAT_NV61,
> > > > > +		.v4l2_fmt =3D V4L2_PIX_FMT_NV61,
> > > > >  		.depth =3D 0,
> > > > >  		.num_planes =3D 2,
> > > > >  		.cpp =3D { 1, 2, 0 },
> > > > > @@ -473,6 +496,7 @@ static const struct image_format_info formats=
[] =3D {
> > > > >  		.is_yuv =3D true,
> > > > >  	}, {
> > > > >  		.drm_fmt =3D DRM_FORMAT_NV24,
> > > > > +		.v4l2_fmt =3D V4L2_PIX_FMT_NV24,
> > > > >  		.depth =3D 0,
> > > > >  		.num_planes =3D 2,
> > > > >  		.cpp =3D { 1, 2, 0 },
> > > > > @@ -481,6 +505,7 @@ static const struct image_format_info formats=
[] =3D {
> > > > >  		.is_yuv =3D true,
> > > > >  	}, {
> > > > >  		.drm_fmt =3D DRM_FORMAT_NV42,
> > > > > +		.v4l2_fmt =3D V4L2_PIX_FMT_NV42,
> > > > >  		.depth =3D 0,
> > > > >  		.num_planes =3D 2,
> > > > >  		.cpp =3D { 1, 2, 0 },
> > > > > @@ -489,6 +514,7 @@ static const struct image_format_info formats=
[] =3D {
> > > > >  		.is_yuv =3D true,
> > > > >  	}, {
> > > > >  		.drm_fmt =3D DRM_FORMAT_YUYV,
> > > > > +		.v4l2_fmt =3D V4L2_PIX_FMT_YUYV,
> > > > >  		.depth =3D 0,
> > > > >  		.num_planes =3D 1,
> > > > >  		.cpp =3D { 2, 0, 0 },
> > > > > @@ -497,6 +523,7 @@ static const struct image_format_info formats=
[] =3D {
> > > > >  		.is_yuv =3D true,
> > > > >  	}, {
> > > > >  		.drm_fmt =3D DRM_FORMAT_YVYU,
> > > > > +		.v4l2_fmt =3D V4L2_PIX_FMT_YVYU,
> > > > >  		.depth =3D 0,
> > > > >  		.num_planes =3D 1,
> > > > >  		.cpp =3D { 2, 0, 0 },
> > > > > @@ -505,6 +532,7 @@ static const struct image_format_info formats=
[] =3D {
> > > > >  		.is_yuv =3D true,
> > > > >  	}, {
> > > > >  		.drm_fmt =3D DRM_FORMAT_UYVY,
> > > > > +		.v4l2_fmt =3D V4L2_PIX_FMT_UYVY,
> > > > >  		.depth =3D 0,
> > > > >  		.num_planes =3D 1,
> > > > >  		.cpp =3D { 2, 0, 0 },
> > > > > @@ -513,6 +541,7 @@ static const struct image_format_info formats=
[] =3D {
> > > > >  		.is_yuv =3D true,
> > > > >  	}, {
> > > > >  		.drm_fmt =3D DRM_FORMAT_VYUY,
> > > > > +		.v4l2_fmt =3D V4L2_PIX_FMT_VYUY,
> > > > >  		.depth =3D 0,
> > > > >  		.num_planes =3D 1,
> > > > >  		.cpp =3D { 2, 0, 0 },
> > > > > @@ -632,6 +661,44 @@ const struct image_format_info *image_format=
_drm_lookup(u32 drm)
> > > > >  EXPORT_SYMBOL(image_format_drm_lookup);
> > > > > =20
> > > > >  /**
> > > > > + * __image_format_v4l2_lookup - query information for a given fo=
rmat
> > > > > + * @v4l2: V4L2 fourcc pixel format (V4L2_PIX_FMT_*)
> > > > > + *
> > > > > + * The caller should only pass a supported pixel format to this =
function.
> > > > > + *
> > > > > + * Returns:
> > > > > + * The instance of struct image_format_info that describes the p=
ixel format, or
> > > > > + * NULL if the format is unsupported.
> > > > > + */
> > > > > +const struct image_format_info *__image_format_v4l2_lookup(u32 v=
4l2)
> > > > > +{
> > > > > +	return __image_format_lookup(v4l2_fmt, v4l2);
> > > > > +}
> > > > > +EXPORT_SYMBOL(__image_format_v4l2_lookup);
> > > > > +
> > > > > +/**
> > > > > + * image_format_v4l2_lookup - query information for a given form=
at
> > > > > + * @v4l2: V4L2 fourcc pixel format (V4L2_PIX_FMT_*)
> > > > > + *
> > > > > + * The caller should only pass a supported pixel format to this =
function.
> > > > > + * Unsupported pixel formats will generate a warning in the kern=
el log.
> > > > > + *
> > > > > + * Returns:
> > > > > + * The instance of struct image_format_info that describes the p=
ixel format, or
> > > > > + * NULL if the format is unsupported.
> > > > > + */
> > > > > +const struct image_format_info *image_format_v4l2_lookup(u32 v4l=
2)
> > > > > +{
> > > > > +	const struct image_format_info *format;
> > > > > +
> > > > > +	format =3D __image_format_v4l2_lookup(v4l2);
> > > > > +
> > > > > +	WARN_ON(!format);
> > > > > +	return format;
> > > > > +}
> > > > > +EXPORT_SYMBOL(image_format_v4l2_lookup);
> > > > > +
> > > > > +/**
> > > > >   * image_format_plane_cpp - determine the bytes per pixel value
> > > > >   * @format: pointer to the image_format
> > > > >   * @plane: plane index
> > > >=20
> > > > _______________________________________________
> > > > dri-devel mailing list
> > > > dri-devel@lists.freedesktop.org
> > > > https://lists.freedesktop.org/mailman/listinfo/dri-devel
>=20
>=20

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