Re: [PATCH v2 1/2] [media] CNF4 fourcc for 4 bit-per-pixel packed depth confidence information

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

Hi Sergey,

Thank you for the patch.

The subject line should start with an appropriate prefix. I propose rewriting 
it as

media: v4l: Add 4bpp packed depth confidence format CNF4

Apart from that the patch looks good to me,

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

If you're fine with the subject line change there's no need to resubmit, I'll 
fix it when applying the patch to my tree.

On Wednesday, 12 September 2018 09:42:06 EET dorodnic@gmail.com wrote:
> From: Sergey Dorodnicov <sergey.dorodnicov@intel.com>
> 
> Adding new fourcc CNF4 for 4 bit-per-pixel packed depth confidence
> information provided by Intel RealSense cameras. Every two consecutive
> pixels are packed into a single byte.
> 
> Signed-off-by: Sergey Dorodnicov <sergey.dorodnicov@intel.com>
> Signed-off-by: Evgeni Raikhel <evgeni.raikhel@intel.com>
> ---
>  Documentation/media/uapi/v4l/depth-formats.rst |  1 +
>  Documentation/media/uapi/v4l/pixfmt-cnf4.rst   | 31 +++++++++++++++++++++++
>  drivers/media/v4l2-core/v4l2-ioctl.c           |  1 +
>  include/uapi/linux/videodev2.h                 |  1 +
>  4 files changed, 34 insertions(+)
>  create mode 100644 Documentation/media/uapi/v4l/pixfmt-cnf4.rst
> 
> diff --git a/Documentation/media/uapi/v4l/depth-formats.rst
> b/Documentation/media/uapi/v4l/depth-formats.rst index d1641e9..9533348
> 100644
> --- a/Documentation/media/uapi/v4l/depth-formats.rst
> +++ b/Documentation/media/uapi/v4l/depth-formats.rst
> @@ -14,3 +14,4 @@ Depth data provides distance to points, mapped onto the
> image plane
> 
>      pixfmt-inzi
>      pixfmt-z16
> +    pixfmt-cnf4
> diff --git a/Documentation/media/uapi/v4l/pixfmt-cnf4.rst
> b/Documentation/media/uapi/v4l/pixfmt-cnf4.rst new file mode 100644
> index 0000000..8f46929
> --- /dev/null
> +++ b/Documentation/media/uapi/v4l/pixfmt-cnf4.rst
> @@ -0,0 +1,31 @@
> +.. -*- coding: utf-8; mode: rst -*-
> +
> +.. _V4L2-PIX-FMT-CNF4:
> +
> +******************************
> +V4L2_PIX_FMT_CNF4 ('CNF4')
> +******************************
> +
> +Depth sensor confidence information as a 4 bits per pixel packed array
> +
> +Description
> +===========
> +
> +Proprietary format used by Intel RealSense Depth cameras containing depth
> +confidence information in range 0-15 with 0 indicating that the sensor was
> +unable to resolve any signal and 15 indicating maximum level of confidence
> for +the specific sensor (actual error margins might change from sensor to
> sensor). +
> +Every two consecutive pixels are packed into a single byte.
> +Bits 0-3 of byte n refer to confidence value of depth pixel 2*n,
> +bits 4-7 to confidence value of depth pixel 2*n+1.
> +
> +**Bit-packed representation.**
> +
> +.. flat-table::
> +    :header-rows:  0
> +    :stub-columns: 0
> +    :widths: 64 64
> +
> +    * - Y'\ :sub:`01[3:0]`\ (bits 7--4) Y'\ :sub:`00[3:0]`\ (bits 3--0)
> +      - Y'\ :sub:`03[3:0]`\ (bits 7--4) Y'\ :sub:`02[3:0]`\ (bits 3--0)
> diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c
> b/drivers/media/v4l2-core/v4l2-ioctl.c index 54afc9c..f9aa8bd 100644
> --- a/drivers/media/v4l2-core/v4l2-ioctl.c
> +++ b/drivers/media/v4l2-core/v4l2-ioctl.c
> @@ -1189,6 +1189,7 @@ static void v4l_fill_fmtdesc(struct v4l2_fmtdesc *fmt)
> case V4L2_PIX_FMT_Y12I:		descr = "Interleaved 12-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;
> case V4L2_PIX_FMT_PAL8:		descr = "8-bit Palette"; break;
>  	case V4L2_PIX_FMT_UV8:		descr = "8-bit Chrominance UV 4-4"; break;
>  	case V4L2_PIX_FMT_YVU410:	descr = "Planar YVU 4:1:0"; break;
> diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
> index 622f047..2837c93 100644
> --- a/include/uapi/linux/videodev2.h
> +++ b/include/uapi/linux/videodev2.h
> @@ -676,6 +676,7 @@ struct v4l2_pix_format {
>  #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_INZI    
> v4l2_fourcc('I', 'N', 'Z', 'I') /* Intel Planar Greyscale 10-bit and Depth
> 16-bit */ +#define V4L2_PIX_FMT_CNF4     v4l2_fourcc('C', 'N', 'F', '4') /*
> Intel 4-bit packed depth confidence information */
> 
>  /* 10bit raw bayer packed, 32 bytes for every 25 pixels, last LSB 6 bits
> unused */ #define V4L2_PIX_FMT_IPU3_SBGGR10	v4l2_fourcc('i', 'p', '3', 
'b')
> /* IPU3 packed 10-bit BGGR bayer */


-- 
Regards,

Laurent Pinchart