Re: [PATCH v11 15/66] media: uapi: Add generic CSI-2 raw pixelformats

[Sakari Ailus <sakari.ailus@linux.intel.com>]

Hi Laurent,

On Wed, Sep 03, 2025 at 04:20:52PM +0200, Laurent Pinchart wrote:
> On Tue, Sep 02, 2025 at 04:16:21PM +0300, Sakari Ailus wrote:
> > On Mon, Sep 01, 2025 at 03:25:01PM +0200, Jacopo Mondi wrote:
> > > On Mon, Aug 25, 2025 at 12:50:16PM +0300, Sakari Ailus wrote:
> > > > Add generic raw pixelformats for bit depths 8, 10, 12 and 14. These
> > > > formats are CSI-2 packed, apart from the 8-bit format.
> > > >
> > > > Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> > > > ---
> > > >  .../media/v4l/pixfmt-raw-generic.rst          | 175 ++++++++++++++++++
> > > >  .../userspace-api/media/v4l/pixfmt.rst        |   1 +
> > > >  drivers/media/v4l2-core/v4l2-ioctl.c          |   4 +
> > > >  include/uapi/linux/videodev2.h                |   6 +
> > > >  4 files changed, 186 insertions(+)
> > > >  create mode 100644 Documentation/userspace-api/media/v4l/pixfmt-raw-generic.rst
> > > >
> > > > diff --git a/Documentation/userspace-api/media/v4l/pixfmt-raw-generic.rst b/Documentation/userspace-api/media/v4l/pixfmt-raw-generic.rst
> > > > new file mode 100644
> > > > index 000000000000..9fda7a36cd3a
> > > > --- /dev/null
> > > > +++ b/Documentation/userspace-api/media/v4l/pixfmt-raw-generic.rst
> > > > @@ -0,0 +1,175 @@
> > > > +.. SPDX-License-Identifier: GPL-2.0 OR GFDL-1.1-no-invariants-or-later
> > > > +
> > > > +************************************************************************************************************************************************************************************************************************************************************************************
> > > > +V4L2_PIX_FMT_RAW_8 ('RAW8'), V4L2_PIX_FMT_RAW_CSI2_10 ('RACA'), V4L2_PIX_FMT_RAW_CSI2_12 ('RACC'), V4L2_PIX_FMT_RAW_CSI2_14 ('RACE'), V4L2_PIX_FMT_RAW_16 ('RAWG'), V4L2_PIX_FMT_RAW_CSI2_20 ('RACK'), V4L2_PIX_FMT_RAW_24 ('RAWO'), V4L2_PIX_FMT_RAW_CSI2_28 ('RACS')
> > > > +************************************************************************************************************************************************************************************************************************************************************************************
> 
> You seem to have too many stars.

I'll try to find someone who would be interested in the extra stars.

> 
> > > 
> > > I see in your branch
> > > "media: uapi: Add generic CSI-2 raw pixelformats for 16, 20, 24 and 28 bpp"
> > > 
> > > Which adds pixel formats for the additional formats not documented in
> > > this patch but mentioned here above in the header.
> > > 
> > > Should you squash it with this patch ?
> > 
> > The reason these are being postponed is that we haven't yet seen devices
> > using them. The systems these are used in tend to be little endian while
> > the format documentation suggests big endian byte order. That'd be
> > inconvenient. So we'd like to see what do they actually use.
> > 
> > I'll move the extra ones to the other patch.
> > 
> > > > +
> > > > +
> > > > +Generic line-based image data formats
> > > 
> > > Does "line-based" applies to image formats as well or to metadata only ?
> > 
> > These, too.
> 
> I would write "Generic line-based raw image data formats".

Sounds good.

> 
> > > > +
> > > > +
> > > > +Description
> > > > +===========
> > > > +
> > > > +These generic raw image data formats define the memory layout of the data
> > > > +without defining the order of the pixels in the format or even the CFA (Colour
> > > 
> > > What about s/in the format// ?
> > 
> > Yes.
> > 
> > > > +Filter Array) itself. See also :ref:`source routes <subdev-routing>`.
> > > 
> > > I might have missed why the reference to the routing documentation.
> > 
> > I think this bit can be removed now.
> 
> Agreed.
> 
> > > > +
> > > > +.. _v4l2-pix-fmt-raw-8:
> > > > +
> > > > +V4L2_PIX_FMT_RAW_8
> > > > +------------------
> > > > +
> > > > +The V4L2_PIX_FMT_GENERIC_8 format is a plain 8-bit raw pixel data format. This
> 
> s/V4L2_PIX_FMT_GENERIC_8/V4L2_PIX_FMT_RAW_8/

Fixed.

> 
> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

Thanks!

> 
> > > > +format is used on CSI-2 for 8 bits per :term:`Data Unit`.
> > > > +
> > > > +**Byte Order Of V4L2_PIX_FMT_RAW_8.**
> > > > +Each cell is one byte. "P" denotes a pixel.
> > > > +
> > > > +.. tabularcolumns:: |p{2.4cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|
> > > > +
> > > > +.. flat-table:: Sample 4x2 Image Frame
> > > > +    :header-rows:  0
> > > > +    :stub-columns: 0
> > > > +    :widths: 12 8 8 8 8
> > > > +
> > > > +    * - start + 0:
> > > > +      - P\ :sub:`00`
> > > > +      - P\ :sub:`10`
> > > > +      - P\ :sub:`20`
> > > > +      - P\ :sub:`30`
> > > > +    * - start + 4:
> > > > +      - P\ :sub:`01`
> > > > +      - P\ :sub:`11`
> > > > +      - P\ :sub:`21`
> > > > +      - P\ :sub:`31`
> > > > +
> > > > +.. _v4l2-pix-fmt-raw-csi2-10:
> > > > +
> > > > +V4L2_PIX_FMT_RAW_CSI2_10
> > > > +------------------------
> > > > +
> > > > +V4L2_PIX_FMT_RAW_CSI2_10 contains 10-bit packed image data, with four bytes
> > > > +containing the top 8 bits of the pixels followed by lowest 2 bits of the pixels
> > > > +packed into one byte. This format is typically used by CSI-2 receivers with
> > > > +a source that transmits MEDIA_BUS_FMT_RAW_10 and the CSI-2 receiver writes the
> > > > +received data to memory as-is.
> > > > +
> > > > +The packing of the data follows the MIPI CSI-2 specification.
> > > > +
> > > > +**Byte Order Of V4L2_PIX_FMT_RAW_CSI2_10.**
> > > > +Each cell is one byte. "P" denotes a pixel.
> > > > +
> > > > +.. tabularcolumns:: |p{2.4cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{1.8cm}|
> > > > +
> > > > +.. flat-table:: Sample 4x2 Image Frame
> > > > +    :header-rows:  0
> > > > +    :stub-columns: 0
> > > > +    :widths: 12 8 8 8 8 8
> > > > +
> > > > +    * - start + 0:
> > > > +      - P\ :sub:`00 bits 9--2`
> > > > +      - P\ :sub:`10 bits 9--2`
> > > > +      - P\ :sub:`20 bits 9--2`
> > > > +      - P\ :sub:`30 bits 9--2`
> > > > +      - P\ :sub:`00 bits 1--0` (bits 1--0)
> > > > +        P\ :sub:`10 bits 1--0` (bits 3--2)
> > > > +        P\ :sub:`20 bits 1--0` (bits 5--4)
> > > > +        P\ :sub:`30 bits 1--0` (bits 7--6)
> > > > +    * - start + 5:
> > > > +      - P\ :sub:`01 bits 9--2`
> > > > +      - P\ :sub:`11 bits 9--2`
> > > > +      - P\ :sub:`21 bits 9--2`
> > > > +      - P\ :sub:`31 bits 9--2`
> > > > +      - P\ :sub:`01 bits 1--0` (bits 1--0)
> > > > +        P\ :sub:`11 bits 1--0` (bits 3--2)
> > > > +        P\ :sub:`21 bits 1--0` (bits 5--4)
> > > > +        P\ :sub:`31 bits 1--0` (bits 7--6)
> > > > +
> > > > +.. _v4l2-pix-fmt-raw-csi2-12:
> > > > +
> > > > +V4L2_PIX_FMT_RAW_CSI2_12
> > > > +------------------------
> > > > +
> > > > +V4L2_PIX_FMT_RAW_CSI2_12 contains 12-bit packed image data, with two bytes
> > > > +containing the top 8 bits of the pixels followed by lowest 4 bits of the pixels
> > > > +packed into 1 byte. This format is typically used by CSI-2 receivers with
> > > > +a source that transmits MEDIA_BUS_FMT_RAW_12 and the CSI-2 receiver writes the
> > > > +received data to memory as-is.
> > > > +
> > > > +The packing of the data follows the MIPI CSI-2 specification.
> > > > +
> > > > +**Byte Order Of V4L2_PIX_FMT_RAW_CSI2_12.**
> > > > +Each cell is one byte. "P" denotes a pixel.
> > > > +
> > > > +.. tabularcolumns:: |p{2.4cm}|p{1.2cm}|p{1.2cm}|p{1.8cm}|p{1.2cm}|p{1.2cm}|p{1.8cm}|
> > > > +
> > > > +.. flat-table:: Sample 4x2 Image Frame
> > > > +    :header-rows:  0
> > > > +    :stub-columns: 0
> > > > +    :widths: 12 8 8 8 8 8 8
> > > > +
> > > > +    * - start + 0:
> > > > +      - P\ :sub:`00 bits 11--4`
> > > > +      - P\ :sub:`10 bits 11--4`
> > > > +      - P\ :sub:`00 bits 3--0` (bits 3--0)
> > > > +        P\ :sub:`10 bits 3--0` (bits 7--4)
> > > > +      - P\ :sub:`20 bits 11--4`
> > > > +      - P\ :sub:`30 bits 11--4`
> > > > +      - P\ :sub:`20 bits 3--0` (bits 3--0)
> > > > +        P\ :sub:`30 bits 3--0` (bits 7--4)
> > > > +    * - start + 6:
> > > > +      - P\ :sub:`01 bits 11--4`
> > > > +      - P\ :sub:`11 bits 11--4`
> > > > +      - P\ :sub:`01 bits 3--0` (bits 3--0)
> > > > +        P\ :sub:`11 bits 3--0` (bits 7--4)
> > > > +      - P\ :sub:`21 bits 11--4`
> > > > +      - P\ :sub:`31 bits 11--4`
> > > > +      - P\ :sub:`21 bits 3--0` (bits 3--0)
> > > > +        P\ :sub:`31 bits 3--0` (bits 7--4)
> > > > +
> > > > +.. _v4l2-pix-fmt-raw-csi2-14:
> > > > +
> > > > +V4L2_PIX_FMT_RAW_CSI2_14
> > > > +------------------------
> > > > +
> > > > +V4L2_PIX_FMT_RAW_CSI2_14 contains 14-bit packed image data, with four bytes
> > > > +containing the top 8 bits of the pixels followed by lowest 6 bits of the pixels
> > > > +packed into three bytes. This format is typically used by CSI-2 receivers with a
> > > > +source that transmits MEDIA_BUS_FMT_RAW_14 and the CSI-2 receiver writes the
> > > > +received data to memory as-is.
> > > > +
> > > > +The packing of the data follows the MIPI CSI-2 specification.
> > > > +
> > > > +**Byte Order Of V4L2_PIX_FMT_RAW_CSI2_14.**
> > > > +Each cell is one byte. "P" denotes a pixel.
> > > > +
> > > > +.. tabularcolumns:: |p{2.4cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{1.8cm}|p{1.8cm}|p{1.8cm}|
> > > > +
> > > > +.. flat-table:: Sample 4x2 Image Frame
> > > > +    :header-rows:  0
> > > > +    :stub-columns: 0
> > > > +    :widths: 12 8 8 8 8 8 8 8
> > > > +
> > > > +    * - start + 0:
> > > > +      - P\ :sub:`00 bits 13--6`
> > > > +      - P\ :sub:`10 bits 13--6`
> > > > +      - P\ :sub:`20 bits 13--6`
> > > > +      - P\ :sub:`30 bits 13--6`
> > > > +      - P\ :sub:`10 bits 1--0` (bits 7--6)
> > > > +        P\ :sub:`00 bits 5--0` (bits 5--0)
> > > > +      - P\ :sub:`20 bits 3--0` (bits 7--4)
> > > > +        P\ :sub:`10 bits 5--2` (bits 3--0)
> > > > +      - P\ :sub:`30 bits 5--0` (bits 7--2)
> > > > +        P\ :sub:`20 bits 5--4` (bits 1--0)
> > > > +    * - start + 7:
> > > > +      - P\ :sub:`01 bits 13--6`
> > > > +      - P\ :sub:`11 bits 13--6`
> > > > +      - P\ :sub:`21 bits 13--6`
> > > > +      - P\ :sub:`31 bits 13--6`
> > > > +      - P\ :sub:`11 bits 1--0` (bits 7--6)
> > > > +        P\ :sub:`01 bits 5--0` (bits 5--0)
> > > > +      - P\ :sub:`21 bits 3--0` (bits 7--4)
> > > > +        P\ :sub:`11 bits 5--2` (bits 3--0)
> > > > +      - P\ :sub:`31 bits 5--0` (bits 7--2)
> > > > +        P\ :sub:`21 bits 5--4` (bits 1--0)
> > > > diff --git a/Documentation/userspace-api/media/v4l/pixfmt.rst b/Documentation/userspace-api/media/v4l/pixfmt.rst
> > > > index 11dab4a90630..d917190c717d 100644
> > > > --- a/Documentation/userspace-api/media/v4l/pixfmt.rst
> > > > +++ b/Documentation/userspace-api/media/v4l/pixfmt.rst
> > > > @@ -25,6 +25,7 @@ see also :ref:`VIDIOC_G_FBUF <VIDIOC_G_FBUF>`.)
> > > >      pixfmt-indexed
> > > >      pixfmt-rgb
> > > >      pixfmt-bayer
> > > > +    pixfmt-raw-generic
> > > >      yuv-formats
> > > >      hsv-formats
> > > >      depth-formats
> > > > diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
> > > > index 01cf52c3ea33..e538c1230631 100644
> > > > --- a/drivers/media/v4l2-core/v4l2-ioctl.c
> > > > +++ b/drivers/media/v4l2-core/v4l2-ioctl.c
> > > > @@ -1434,6 +1434,10 @@ static void v4l_fill_fmtdesc(struct v4l2_fmtdesc *fmt)
> > > >  	case V4L2_PIX_FMT_SGBRG16:	descr = "16-bit Bayer GBGB/RGRG"; break;
> > > >  	case V4L2_PIX_FMT_SGRBG16:	descr = "16-bit Bayer GRGR/BGBG"; break;
> > > >  	case V4L2_PIX_FMT_SRGGB16:	descr = "16-bit Bayer RGRG/GBGB"; break;
> > > > +	case V4L2_PIX_FMT_RAW_8:	descr = "8-bit Raw"; break;
> > > > +	case V4L2_PIX_FMT_RAW_CSI2_10:	descr = "10-bit Raw, CSI-2 Packed"; break;
> > > > +	case V4L2_PIX_FMT_RAW_CSI2_12:	descr = "12-bit Raw, CSI-2 Packed"; break;
> > > > +	case V4L2_PIX_FMT_RAW_CSI2_14:	descr = "14-bit Raw, CSI-2 Packed"; break;
> > > >  	case V4L2_PIX_FMT_RAW_CRU20:	descr = "14-bit Raw CRU Packed"; break;
> > > >  	case V4L2_PIX_FMT_SN9C20X_I420:	descr = "GSPCA SN9C20X I420"; break;
> > > >  	case V4L2_PIX_FMT_SPCA501:	descr = "GSPCA SPCA501"; break;
> > > > diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
> > > > index 3dd9fa45dde1..c4c4f3eb67e1 100644
> > > > --- a/include/uapi/linux/videodev2.h
> > > > +++ b/include/uapi/linux/videodev2.h
> > > > @@ -745,6 +745,12 @@ struct v4l2_pix_format {
> > > >  #define V4L2_PIX_FMT_SGRBG16 v4l2_fourcc('G', 'R', '1', '6') /* 16  GRGR.. BGBG.. */
> > > >  #define V4L2_PIX_FMT_SRGGB16 v4l2_fourcc('R', 'G', '1', '6') /* 16  RGRG.. GBGB.. */
> > > >
> > > > +/* Generic CSI-2 packed raw pixel formats */
> > > > +#define V4L2_PIX_FMT_RAW_8 v4l2_fourcc('R', 'A', 'W', '8')
> > > > +#define V4L2_PIX_FMT_RAW_CSI2_10 v4l2_fourcc('R', 'A', 'C', 'A')
> > > > +#define V4L2_PIX_FMT_RAW_CSI2_12 v4l2_fourcc('R', 'A', 'C', 'C')
> > > > +#define V4L2_PIX_FMT_RAW_CSI2_14 v4l2_fourcc('R', 'A', 'C', 'E')
> > > > +
> > >
> > > With
> > > "media: uapi: Add generic CSI-2 raw pixelformats for 16, 20, 24 and 28 bpp"
> > > 
> > > and the above minors clarified
> > > Reviewed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
> > 
> > Thank you!
> > 
> > > >  /* HSV formats */
> > > >  #define V4L2_PIX_FMT_HSV24 v4l2_fourcc('H', 'S', 'V', '3')
> > > >  #define V4L2_PIX_FMT_HSV32 v4l2_fourcc('H', 'S', 'V', '4')
> 

-- 
Kind regards,

Sakari Ailus