Re: [PATCH 1/2] v4l: Add luma 16-bit interlaced pixel format

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Dmitry,

Thank you for the patch.

On Mon, Aug 26, 2024 at 04:04:23PM +0300, Dmitry Perchanov wrote:
> The formats added by this patch are:
> 
>         V4L2_PIX_FMT_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@intel.com>
> ---
>  .../userspace-api/media/v4l/pixfmt-y16i.rst   | 74 +++++++++++++++++++
>  .../userspace-api/media/v4l/yuv-formats.rst   |  1 +
>  drivers/media/v4l2-core/v4l2-ioctl.c          |  1 +
>  include/uapi/linux/videodev2.h                |  1 +
>  4 files changed, 77 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..fe4f441cd63c
> --- /dev/null
> +++ b/Documentation/userspace-api/media/v4l/pixfmt-y16i.rst
> @@ -0,0 +1,74 @@
> +.. 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 16-bit word in the little-endian order.
> +The first pixel is from the left source.

You can reflow this to 80 columns:

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.

With this,

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

I can make that change locally, no need to send a new version just for
this.

> +
> +**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/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
> index 5eb4d797d259..4fffa5739895 100644
> --- a/drivers/media/v4l2-core/v4l2-ioctl.c
> +++ b/drivers/media/v4l2-core/v4l2-ioctl.c
> @@ -1327,6 +1327,7 @@ static void v4l_fill_fmtdesc(struct v4l2_fmtdesc *fmt)
>  	case V4L2_PIX_FMT_Y14P:		descr = "14-bit Greyscale (MIPI 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/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
> index 4e91362da6da..46f616e43ad6 100644
> --- a/include/uapi/linux/videodev2.h
> +++ b/include/uapi/linux/videodev2.h
> @@ -797,6 +797,7 @@ 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