Hi Sakari, Hans
On Tue, Aug 08, 2023 at 10:22:21AM +0200, Hans Verkuil wrote:
> On 08/08/2023 09:55, Sakari Ailus wrote:
> > Generic 8-bit metadata formats define the in-memory data layout but not
> > the format of the data itself. The reasoning for having such formats is to
> > allow CSI-2 receiver drivers to receive and DMA drivers to write the data
> > to memory without knowing a large number of device specific formats.
> >
> > These formats may be used only in conjunction of a Media controller
> > pipeline where the internal pad of the source sub-device defines the
> > specific format of the data (using an mbus code).
> >
> > Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
> > ---
> > .../userspace-api/media/v4l/meta-formats.rst | 1 +
> > .../media/v4l/metafmt-generic.rst | 331 ++++++++++++++++++
> > drivers/media/v4l2-core/v4l2-ioctl.c | 8 +
> > include/uapi/linux/videodev2.h | 9 +
> > 4 files changed, 349 insertions(+)
> > create mode 100644 Documentation/userspace-api/media/v4l/metafmt-generic.rst
> >
> > diff --git a/Documentation/userspace-api/media/v4l/meta-formats.rst b/Documentation/userspace-api/media/v4l/meta-formats.rst
> > index 0bb61fc5bc00..919f595576b9 100644
> > --- a/Documentation/userspace-api/media/v4l/meta-formats.rst
> > +++ b/Documentation/userspace-api/media/v4l/meta-formats.rst
> > @@ -19,3 +19,4 @@ These formats are used for the :ref:`metadata` interface only.
> > metafmt-vsp1-hgo
> > metafmt-vsp1-hgt
> > metafmt-vivid
> > + metafmt-generic
> > diff --git a/Documentation/userspace-api/media/v4l/metafmt-generic.rst b/Documentation/userspace-api/media/v4l/metafmt-generic.rst
> > new file mode 100644
> > index 000000000000..a27bfc721edf
> > --- /dev/null
> > +++ b/Documentation/userspace-api/media/v4l/metafmt-generic.rst
> > @@ -0,0 +1,331 @@
> > +.. SPDX-License-Identifier: GPL-2.0 OR GFDL-1.1-no-invariants-or-later
> > +
> > +**************************************************************************************************************************************************************************************************************************************************************************************************************************
> > +V4L2_META_FMT_GENERIC_8 ('MET8'), V4L2_META_FMT_GENERIC_CSI2_10 ('MC1A'), V4L2_META_FMT_GENERIC_CSI2_12 ('MC1C'), V4L2_META_FMT_GENERIC_CSI2_14 ('MC1E'), V4L2_META_FMT_GENERIC_CSI2_16 ('MC1G'), V4L2_META_FMT_GENERIC_CSI2_20 ('MC1K'), V4L2_META_FMT_GENERIC_CSI2_24 ('MC1O'), V4L2_META_FMT_GENERIC_CSI2_2_24 ('MC2O')
> > +**************************************************************************************************************************************************************************************************************************************************************************************************************************
> > +
> > +
> > +Generic line-based metadata formats
> > +
> > +
> > +Description
> > +===========
> > +
> > +These generic line-based metadata formats define the memory layout of the data
> > +without defining the format or meaning of the metadata itself. These formats may
> > +only be used with a Media controller pipeline where the more specific format is
> > +defined in an :ref:`internal source pad <MEDIA-PAD-FL-INTERNAL>` of the source
> > +sub-device. See also :ref:`source routes <v4l2-subdev-source-routes>`.
> > +
> > +.. _v4l2-meta-fmt-generic-8:
> > +
> > +V4L2_META_FMT_GENERIC_8
> > +-----------------------
> > +
> > +The V4L2_META_FMT_GENERIC_8 format is a plain 8-bit metadata format.
> > +
> > +This format is also used on CSI-2 on both 8 bits per sample as well as on
>
> on both 8 bits per sample as well as on ->
> for both 8 bits per sample as well as for
>
> Same elsewhere.
>
> > +16 bits per sample when two bytes of metadata are packed into one sample.
> > +
> > +**Byte Order Of V4L2_META_FMT_GENERIC_8.**
> > +Each cell is one byte. "M" denotes a byte of metadata.
> > +
> > +.. tabularcolumns:: |p{2.4cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|
> > +
> > +.. flat-table::
> > + :header-rows: 0
> > + :stub-columns: 0
> > + :widths: 12 8 8 8 8
> > +
> > + * - start + 0:
> > + - M\ :sub:`00`
> > + - M\ :sub:`10`
> > + - M\ :sub:`20`
> > + - M\ :sub:`30`
> > + * - start + 4:
> > + - M\ :sub:`01`
> > + - M\ :sub:`11`
> > + - M\ :sub:`21`
> > + - M\ :sub:`31`
> > +
> > +.. _v4l2-meta-fmt-generic-csi2-10:
> > +
> > +V4L2_META_FMT_GENERIC_CSI2_10
> > +-----------------------------
> > +
> > +V4L2_META_FMT_GENERIC_CSI2_10 contains packed 8-bit generic metadata, 10 bits
> > +for each 8 bits of data. Every four bytes of metadata is followed by a single
> > +byte of padding. The way the data is stored follows the CSI-2 specification.
> > +
> > +This format is also used on CSI-2 on 20 bits per sample format that packs two
> > +bytes of metadata into one sample.
> > +
> > +This format is little endian.
> > +
> > +**Byte Order Of V4L2_META_FMT_GENERIC_CSI2_10.**
> > +Each cell is one byte. "M" denotes a byte of metadata and "p" a byte of padding.
>
> I think you should document whether the padding is always 0 or can be any value.
> Perhaps 'X' is a better 'name' for the padding byte in the latter case.
>
Did I get this right that this format is supposed to work as the RAW10
CSI-2 packed image format, where 4 bytes contain the higher 8 bits of
the 10 bits sample and the 5th byte every 4 contains the lower 2 bits of
the previous 4 sample ?
If that's the case, is 'padding' the correct term here ?
> > +
> > +.. tabularcolumns:: |p{2.4cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{.8cm}|
> > +
> > +.. flat-table::
> > + :header-rows: 0
> > + :stub-columns: 0
> > + :widths: 12 8 8 8 8 8
> > +
> > + * - start + 0:
> > + - M\ :sub:`00`
> > + - M\ :sub:`10`
> > + - M\ :sub:`20`
> > + - M\ :sub:`30`
> > + - p
> > + * - start + 5:
> > + - M\ :sub:`01`
> > + - M\ :sub:`11`
> > + - M\ :sub:`21`
> > + - M\ :sub:`31`
> > + - p
> > +
> > +.. _v4l2-meta-fmt-generic-csi2-12:
> > +
> > +V4L2_META_FMT_GENERIC_CSI2_12
> > +-----------------------------
> > +
> > +V4L2_META_FMT_GENERIC_CSI2_12 contains packed 8-bit generic metadata, 12 bits
> > +for each 8 bits of data. Every four bytes of metadata is followed by two bytes
> > +of padding. The way the data is stored follows the CSI-2 specification.
> > +
> > +This format is little endian.
> > +
> > +**Byte Order Of V4L2_META_FMT_GENERIC_CSI2_12.**
> > +Each cell is one byte. "M" denotes a byte of metadata and "p" a byte of padding.
> > +
> > +.. tabularcolumns:: |p{2.4cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{.8cm}|p{.8cm}|
> > +
> > +.. flat-table::
> > + :header-rows: 0
> > + :stub-columns: 0
> > + :widths: 12 8 8 8 8 8 8
> > +
> > + * - start + 0:
> > + - M\ :sub:`00`
> > + - M\ :sub:`10`
> > + - M\ :sub:`20`
> > + - M\ :sub:`30`
> > + - p
> > + - p
> > + * - start + 6:
> > + - M\ :sub:`01`
> > + - M\ :sub:`11`
> > + - M\ :sub:`21`
> > + - M\ :sub:`31`
> > + - p
> > + - p
> > +
> > +.. _v4l2-meta-fmt-generic-csi2-14:
> > +
> > +V4L2_META_FMT_GENERIC_CSI2_14
> > +-----------------------------
> > +
> > +V4L2_META_FMT_GENERIC_CSI2_14 contains packed 8-bit generic metadata, 14 bits
> > +for each 8 bits of data. Every four bytes of metadata is followed by three
> > +bytes of padding. The way the data is stored follows the CSI-2 specification.
> > +
> > +This format is little endian.
> > +
> > +**Byte Order Of V4L2_META_FMT_GENERIC_CSI2_14.**
> > +Each cell is one byte. "M" denotes a byte of metadata and "p" a byte of padding.
> > +
> > +.. tabularcolumns:: |p{2.4cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{1.2cm}|p{.8cm}|p{.8cm}|p{.8cm}|
> > +
> > +.. flat-table::
> > + :header-rows: 0
> > + :stub-columns: 0
> > + :widths: 12 8 8 8 8 8 8 8
> > +
> > + * - start + 0:
> > + - M\ :sub:`00`
> > + - M\ :sub:`10`
> > + - M\ :sub:`20`
> > + - M\ :sub:`30`
> > + - p
> > + - p
> > + - p
> > + * - start + 7:
> > + - M\ :sub:`01`
> > + - M\ :sub:`11`
> > + - M\ :sub:`21`
> > + - M\ :sub:`31`
> > + - p
> > + - p
> > + - p
> > +
> > +.. _v4l2-meta-fmt-generic-csi2-16:
> > +
> > +V4L2_META_FMT_GENERIC_CSI2_16
> > +-----------------------------
> > +
> > +V4L2_META_FMT_GENERIC_CSI2_16 contains packed 8-bit generic metadata, 16 bits
> > +for each 8 bits of data. Every byte of metadata is followed by one byte of
> > +padding. The way the data is stored follows the CSI-2 specification.
> > +
> > +This format is little endian.
> > +
> > +**Byte Order Of V4L2_META_FMT_GENERIC_CSI2_16.**
> > +Each cell is one byte. "M" denotes a byte of metadata and "p" a byte of padding.
> > +
> > +.. tabularcolumns:: |p{2.4cm}|p{1.2cm}|p{.8cm}|p{1.2cm}|p{.8cm}|p{1.2cm}|p{.8cm}|p{1.2cm}|p{.8cm}|
> > +
> > +.. flat-table::
> > + :header-rows: 0
> > + :stub-columns: 0
> > + :widths: 12 8 8 8 8 8 8 8 8
> > +
> > + * - start + 0:
> > + - M\ :sub:`00`
> > + - p
> > + - M\ :sub:`10`
> > + - p
> > + - M\ :sub:`20`
> > + - p
> > + - M\ :sub:`30`
> > + - p
> > + * - start + 8:
> > + - M\ :sub:`01`
> > + - p
> > + - M\ :sub:`11`
> > + - p
> > + - M\ :sub:`21`
> > + - p
> > + - M\ :sub:`31`
> > + - p
> > +
> > +.. _v4l2-meta-fmt-generic-csi2-20:
> > +
> > +V4L2_META_FMT_GENERIC_CSI2_20
> > +-----------------------------
> > +
> > +V4L2_META_FMT_GENERIC_CSI2_20 contains packed 8-bit generic metadata, 20 bits
> > +for each 8 bits of data. Every byte of metadata is followed by alternating one
> > +and two bytes of padding. The way the data is stored follows the CSI-2
> > +specification.
> > +
> > +This format is little endian.
> > +
> > +**Byte Order Of V4L2_META_FMT_GENERIC_CSI2_20.**
> > +Each cell is one byte. "M" denotes a byte of metadata and "p" a byte of padding.
> > +
> > +.. tabularcolumns:: |p{2.4cm}|p{1.2cm}|p{.8cm}|p{1.2cm}|p{.8cm}|p{.8cm}|p{1.2cm}|p{.8cm}|p{1.2cm}|p{.8cm}|p{.8cm}|
> > +
> > +.. flat-table::
> > + :header-rows: 0
> > + :stub-columns: 0
> > + :widths: 12 8 8 8 8 8 8 8 8 8 8
> > +
> > + * - start + 0:
> > + - M\ :sub:`00`
> > + - p
> > + - M\ :sub:`10`
> > + - p
> > + - p
> > + - M\ :sub:`20`
> > + - p
> > + - M\ :sub:`30`
> > + - p
> > + - p
> > + * - start + 10:
> > + - M\ :sub:`01`
> > + - p
> > + - M\ :sub:`11`
> > + - p
> > + - p
> > + - M\ :sub:`21`
> > + - p
> > + - M\ :sub:`31`
> > + - p
> > + - p
> > +
> > +.. _v4l2-meta-fmt-generic-csi2-24:
> > +
> > +V4L2_META_FMT_GENERIC_CSI2_24
> > +-----------------------------
> > +
> > +V4L2_META_FMT_GENERIC_CSI2_24 contains packed 8-bit generic metadata, 24 bits
> > +for each 8 bits of data. Every byte of metadata is followed by two bytes of
> > +padding. The way the data is stored follows the CSI-2 specification.
> > +
> > +This format is little endian.
> > +
> > +**Byte Order Of V4L2_META_FMT_GENERIC_CSI2_24.**
> > +Each cell is one byte. "M" denotes a byte of metadata and "p" a byte of padding.
> > +
> > +.. tabularcolumns:: |p{2.4cm}|p{1.2cm}|p{.8cm}|p{.8cm}|p{1.2cm}|p{.8cm}|p{.8cm}|p{1.2cm}|p{.8cm}|p{.8cm}|p{1.2cm}|p{.8cm}|p{.8cm}|
> > +
> > +.. flat-table::
> > + :header-rows: 0
> > + :stub-columns: 0
> > + :widths: 12 8 8 8 8 8 8 8 8 8 8 8 8
> > +
> > + * - start + 0:
> > + - M\ :sub:`00`
> > + - p
> > + - p
> > + - M\ :sub:`10`
> > + - p
> > + - p
> > + - M\ :sub:`20`
> > + - p
> > + - p
> > + - M\ :sub:`30`
> > + - p
> > + - p
> > + * - start + 12:
> > + - M\ :sub:`01`
> > + - p
> > + - p
> > + - M\ :sub:`11`
> > + - p
> > + - p
> > + - M\ :sub:`21`
> > + - p
> > + - p
> > + - M\ :sub:`31`
> > + - p
> > + - p
> > +
> > +.. _v4l2-meta-fmt-generic-csi2-2-24:
> > +
> > +V4L2_META_FMT_GENERIC_CSI2_2_24
> > +-------------------------------
> > +
> > +V4L2_META_FMT_GENERIC_CSI2_2_24 contains packed 8-bit generic metadata, 24 bits
> > +for each two times 8 bits of data. Every two bytes of metadata are followed by
> > +one byte of padding. The way the data is stored follows the CSI-2
> > +specification.
> > +
> > +This format is little endian.
> > +
> > +**Byte Order Of V4L2_META_FMT_GENERIC_CSI2_2_24.**
> > +Each cell is one byte. "M" denotes a byte of metadata and "p" a byte of padding.
> > +
> > +.. tabularcolumns:: |p{2.4cm}|p{1.2cm}|p{1.2cm}|p{.8cm}|p{1.2cm}|p{1.2cm}|p{.8cm}|
> > +
> > +.. flat-table::
> > + :header-rows: 0
> > + :stub-columns: 0
> > + :widths: 12 8 8 8 8 8 8
> > +
> > + * - start + 0:
> > + - M\ :sub:`00`
> > + - M\ :sub:`10`
> > + - p
> > + - M\ :sub:`20`
> > + - M\ :sub:`30`
> > + - p
> > + * - start + 6:
> > + - M\ :sub:`01`
> > + - M\ :sub:`11`
> > + - p
> > + - M\ :sub:`21`
> > + - M\ :sub:`31`
> > + - p
> > +
> > diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
> > index f4d9d6279094..fbbddc333a30 100644
> > --- a/drivers/media/v4l2-core/v4l2-ioctl.c
> > +++ b/drivers/media/v4l2-core/v4l2-ioctl.c
> > @@ -1452,6 +1452,14 @@ static void v4l_fill_fmtdesc(struct v4l2_fmtdesc *fmt)
> > case V4L2_PIX_FMT_Y210: descr = "10-bit YUYV Packed"; break;
> > case V4L2_PIX_FMT_Y212: descr = "12-bit YUYV Packed"; break;
> > case V4L2_PIX_FMT_Y216: descr = "16-bit YUYV Packed"; break;
> > + case V4L2_META_FMT_GENERIC_8: descr = "8-bit Generic Metadata"; break;
> > + case V4L2_META_FMT_GENERIC_CSI2_10: descr = "8b Generic Meta, 10b CSI-2"; break;
> > + case V4L2_META_FMT_GENERIC_CSI2_12: descr = "8b Generic Meta, 12b CSI-2"; break;
> > + case V4L2_META_FMT_GENERIC_CSI2_14: descr = "8b Generic Meta, 14b CSI-2"; break;
> > + case V4L2_META_FMT_GENERIC_CSI2_16: descr = "8b Generic Meta, 16b CSI-2"; break;
> > + case V4L2_META_FMT_GENERIC_CSI2_20: descr = "8b Generic Meta, 20b CSI-2"; break;
> > + case V4L2_META_FMT_GENERIC_CSI2_24: descr = "8b Generic Meta, 24b CSI-2"; break;
> > + case V4L2_META_FMT_GENERIC_CSI2_2_24: descr = "2x8b Generic Meta, 24b CSI-2"; break;
> >
> > default:
> > /* Compressed formats */
> > diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
> > index 78260e5d9985..b4284a564025 100644
> > --- a/include/uapi/linux/videodev2.h
> > +++ b/include/uapi/linux/videodev2.h
> > @@ -838,6 +838,15 @@ struct v4l2_pix_format {
> > #define V4L2_META_FMT_RK_ISP1_PARAMS v4l2_fourcc('R', 'K', '1', 'P') /* Rockchip ISP1 3A Parameters */
> > #define V4L2_META_FMT_RK_ISP1_STAT_3A v4l2_fourcc('R', 'K', '1', 'S') /* Rockchip ISP1 3A Statistics */
> >
> > +#define V4L2_META_FMT_GENERIC_8 v4l2_fourcc('M', 'E', 'T', '8') /* Generic 8-bit metadata */
> > +#define V4L2_META_FMT_GENERIC_CSI2_10 v4l2_fourcc('M', 'C', '1', 'A') /* 10-bit CSI-2 packed 8-bit metadata */
> > +#define V4L2_META_FMT_GENERIC_CSI2_12 v4l2_fourcc('M', 'C', '1', 'C') /* 12-bit CSI-2 packed 8-bit metadata */
> > +#define V4L2_META_FMT_GENERIC_CSI2_14 v4l2_fourcc('M', 'C', '1', 'E') /* 14-bit CSI-2 packed 8-bit metadata */
> > +#define V4L2_META_FMT_GENERIC_CSI2_16 v4l2_fourcc('M', 'C', '1', 'G') /* 16-bit CSI-2 packed 8-bit metadata */
> > +#define V4L2_META_FMT_GENERIC_CSI2_20 v4l2_fourcc('M', 'C', '1', 'K') /* 20-bit CSI-2 packed 8-bit metadata */
> > +#define V4L2_META_FMT_GENERIC_CSI2_24 v4l2_fourcc('M', 'C', '1', 'O') /* 24-bit CSI-2 packed 8-bit metadata */
> > +#define V4L2_META_FMT_GENERIC_CSI2_2_24 v4l2_fourcc('M', 'C', '2', 'O') /* 2 bytes of 8-bit metadata, 24-bit CSI-2 packed */
> > +
> > /* priv field value to indicates that subsequent fields are valid. */
> > #define V4L2_PIX_FMT_PRIV_MAGIC 0xfeedcafe
> >
>
> Regards,
>
> Hans
