Hi Dmitry,
Thank you for the patch.
On Sun, Jul 28, 2024 at 06:35:57AM -0400, Dmitry Perchanov wrote:
> The formats added by this patch are:
>
> V4L2_PIX_FMT_Y16I
> UVC_GUID_FORMAT_Y16I
>
> Interlaced lumina format primary use in RealSense
> Depth cameras with stereo stream for left and right
> image sensors.
>
> Signed-off-by: Dmitry Perchanov <dmitry.perchanov@xxxxxxxxx>
The format itself looks fine. Could you split this patch in two, with
one patch that defines the new format (documentation, v4l2-ioctl.c and
videodev2.h), and another patch that adds it to the uvcvideo driver
(drivers/media/common/uvc.c, include/linux/usb/uvc.h) ? We usually do so
to ease backporting.
> ---
> .../userspace-api/media/v4l/pixfmt-y16i.rst | 80 +++++++++++++++++++
> .../userspace-api/media/v4l/yuv-formats.rst | 1 +
> drivers/media/common/uvc.c | 4 +
> drivers/media/v4l2-core/v4l2-ioctl.c | 1 +
> include/linux/usb/uvc.h | 3 +
> include/uapi/linux/videodev2.h | 1 +
> 6 files changed, 90 insertions(+)
> create mode 100644 Documentation/userspace-api/media/v4l/pixfmt-y16i.rst
>
> diff --git a/Documentation/userspace-api/media/v4l/pixfmt-y16i.rst b/Documentation/userspace-api/media/v4l/pixfmt-y16i.rst
> new file mode 100644
> index 000000000000..3303b7832cdb
> --- /dev/null
> +++ b/Documentation/userspace-api/media/v4l/pixfmt-y16i.rst
> @@ -0,0 +1,80 @@
> +.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
> +
> +.. _V4L2-PIX-FMT-Y16I:
> +
> +**************************
> +V4L2_PIX_FMT_Y16I ('Y16I')
> +**************************
> +
> +Interleaved grey-scale image, e.g. from a stereo-pair
> +
> +
> +Description
> +===========
> +
> +This is a grey-scale image with a depth of 16 bits per pixel, but with
> +pixels from 2 sources interleaved and unpacked. Each pixel is stored
> +in a 32-bit word in the little-endian order. On a little-endian machine
> +these pixels can be deinterlaced using
> +
> +.. code-block:: c
> +
> + __u8 *buf;
> + left0 = 0xffff & *(__u16 *)buf;
> + right0 = 0xffff & *((__u16 *)buf + 1);
I think this is a bit overkill. I would simply write
This is a grey-scale image with a depth of 16 bits per pixel, but with pixels
from 2 sources interleaved and unpacked. Each pixel is stored in a 16-bit word
in the little-endian order. The first pixel is from the left source.
> +
> +**Pixel unpacked representation.**
> +Left/Right pixels 16-bit unpacked - 16-bit for each interleaved pixel.
> +
> +.. flat-table::
> + :header-rows: 0
> + :stub-columns: 0
> +
> + * - Y'\ :sub:`0L[7:0]`
> + - Y'\ :sub:`0L[15:8]`
> + - Y'\ :sub:`0R[7:0]`
> + - Y'\ :sub:`0R[15:8]`
> +
> +**Byte Order.**
> +Each cell is one byte.
> +
> +.. flat-table::
> + :header-rows: 0
> + :stub-columns: 0
> +
> + * - start + 0:
> + - Y'\ :sub:`00Llow`
> + - Y'\ :sub:`00Lhigh`
> + - Y'\ :sub:`00Rlow`
> + - Y'\ :sub:`00Rhigh`
> + - Y'\ :sub:`01Llow`
> + - Y'\ :sub:`01Lhigh`
> + - Y'\ :sub:`01Rlow`
> + - Y'\ :sub:`01Rhigh`
> + * - start + 8:
> + - Y'\ :sub:`10Llow`
> + - Y'\ :sub:`10Lhigh`
> + - Y'\ :sub:`10Rlow`
> + - Y'\ :sub:`10Rhigh`
> + - Y'\ :sub:`11Llow`
> + - Y'\ :sub:`11Lhigh`
> + - Y'\ :sub:`11Rlow`
> + - Y'\ :sub:`11Rhigh`
> + * - start + 16:
> + - Y'\ :sub:`20Llow`
> + - Y'\ :sub:`20Lhigh`
> + - Y'\ :sub:`20Rlow`
> + - Y'\ :sub:`20Rhigh`
> + - Y'\ :sub:`21Llow`
> + - Y'\ :sub:`21Lhigh`
> + - Y'\ :sub:`21Rlow`
> + - Y'\ :sub:`21Rhigh`
> + * - start + 24:
> + - Y'\ :sub:`30Llow`
> + - Y'\ :sub:`30Lhigh`
> + - Y'\ :sub:`30Rlow`
> + - Y'\ :sub:`30Rhigh`
> + - Y'\ :sub:`31Llow`
> + - Y'\ :sub:`31Lhigh`
> + - Y'\ :sub:`31Rlow`
> + - Y'\ :sub:`31Rhigh`
> diff --git a/Documentation/userspace-api/media/v4l/yuv-formats.rst b/Documentation/userspace-api/media/v4l/yuv-formats.rst
> index 24b34cdfa6fe..78ee406d7647 100644
> --- a/Documentation/userspace-api/media/v4l/yuv-formats.rst
> +++ b/Documentation/userspace-api/media/v4l/yuv-formats.rst
> @@ -269,5 +269,6 @@ image.
> pixfmt-yuv-luma
> pixfmt-y8i
> pixfmt-y12i
> + pixfmt-y16i
> pixfmt-uv8
> pixfmt-m420
> diff --git a/drivers/media/common/uvc.c b/drivers/media/common/uvc.c
> index 9c0ba7a6c185..246fb6da5903 100644
> --- a/drivers/media/common/uvc.c
> +++ b/drivers/media/common/uvc.c
> @@ -120,6 +120,10 @@ static const struct uvc_format_desc uvc_fmts[] = {
> .guid = UVC_GUID_FORMAT_Y12I,
> .fcc = V4L2_PIX_FMT_Y12I,
> },
> + {
> + .guid = UVC_GUID_FORMAT_Y16I,
> + .fcc = V4L2_PIX_FMT_Y16I,
> + },
> {
> .guid = UVC_GUID_FORMAT_Z16,
> .fcc = V4L2_PIX_FMT_Z16,
> diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
> index 6e7b8b682d13..49a17487e196 100644
> --- a/drivers/media/v4l2-core/v4l2-ioctl.c
> +++ b/drivers/media/v4l2-core/v4l2-ioctl.c
> @@ -1314,6 +1314,7 @@ static void v4l_fill_fmtdesc(struct v4l2_fmtdesc *fmt)
> case V4L2_PIX_FMT_IPU3_Y10: descr = "10-bit greyscale (IPU3 Packed)"; break;
> case V4L2_PIX_FMT_Y8I: descr = "Interleaved 8-bit Greyscale"; break;
> case V4L2_PIX_FMT_Y12I: descr = "Interleaved 12-bit Greyscale"; break;
> + case V4L2_PIX_FMT_Y16I: descr = "Interleaved 16-bit Greyscale"; break;
> case V4L2_PIX_FMT_Z16: descr = "16-bit Depth"; break;
> case V4L2_PIX_FMT_INZI: descr = "Planar 10:16 Greyscale Depth"; break;
> case V4L2_PIX_FMT_CNF4: descr = "4-bit Depth Confidence (Packed)"; break;
> diff --git a/include/linux/usb/uvc.h b/include/linux/usb/uvc.h
> index 88d96095bcb1..1c16be20c966 100644
> --- a/include/linux/usb/uvc.h
> +++ b/include/linux/usb/uvc.h
> @@ -118,6 +118,9 @@
> #define UVC_GUID_FORMAT_Y12I \
> { 'Y', '1', '2', 'I', 0x00, 0x00, 0x10, 0x00, \
> 0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71}
> +#define UVC_GUID_FORMAT_Y16I \
> + { 'Y', '1', '6', 'I', 0x00, 0x00, 0x10, 0x00, \
> + 0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71}
> #define UVC_GUID_FORMAT_Z16 \
> { 'Z', '1', '6', ' ', 0x00, 0x00, 0x10, 0x00, \
> 0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71}
> diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
> index a8015e5e7fa4..d152027021d3 100644
> --- a/include/uapi/linux/videodev2.h
> +++ b/include/uapi/linux/videodev2.h
> @@ -793,6 +793,7 @@ struct v4l2_pix_format {
> #define V4L2_PIX_FMT_S5C_UYVY_JPG v4l2_fourcc('S', '5', 'C', 'I') /* S5C73M3 interleaved UYVY/JPEG */
> #define V4L2_PIX_FMT_Y8I v4l2_fourcc('Y', '8', 'I', ' ') /* Greyscale 8-bit L/R interleaved */
> #define V4L2_PIX_FMT_Y12I v4l2_fourcc('Y', '1', '2', 'I') /* Greyscale 12-bit L/R interleaved */
> +#define V4L2_PIX_FMT_Y16I v4l2_fourcc('Y', '1', '6', 'I') /* Greyscale 16-bit L/R interleaved */
> #define V4L2_PIX_FMT_Z16 v4l2_fourcc('Z', '1', '6', ' ') /* Depth data 16-bit */
> #define V4L2_PIX_FMT_MT21C v4l2_fourcc('M', 'T', '2', '1') /* Mediatek compressed block mode */
> #define V4L2_PIX_FMT_MM21 v4l2_fourcc('M', 'M', '2', '1') /* Mediatek 8-bit block mode, two non-contiguous planes */
--
Regards,
Laurent Pinchart
