Re: [PATCH v3 2/3] docs: media: Document CLL and Mastering display

From: Hans Verkuil
Date: Tue Jan 12 2021 - 05:35:36 EST


On 08/12/2020 15:59, Stanimir Varbanov wrote:
> Document Content light level and Mastering display colour volume.
>
> Signed-off-by: Stanimir Varbanov <stanimir.varbanov@xxxxxxxxxx>
> ---
> .../userspace-api/media/v4l/common.rst | 1 +
> .../media/v4l/ext-ctrls-colorimetry.rst | 88 +++++++++++++++++++
> 2 files changed, 89 insertions(+)
> create mode 100644 Documentation/userspace-api/media/v4l/ext-ctrls-colorimetry.rst
>
> diff --git a/Documentation/userspace-api/media/v4l/common.rst b/Documentation/userspace-api/media/v4l/common.rst
> index 8c263c5a85d8..ea0435182e44 100644
> --- a/Documentation/userspace-api/media/v4l/common.rst
> +++ b/Documentation/userspace-api/media/v4l/common.rst
> @@ -51,6 +51,7 @@ applicable to all devices.
> ext-ctrls-fm-tx
> ext-ctrls-fm-rx
> ext-ctrls-detect
> + ext-ctrls-colorimetry
> fourcc
> format
> planar-apis
> diff --git a/Documentation/userspace-api/media/v4l/ext-ctrls-colorimetry.rst b/Documentation/userspace-api/media/v4l/ext-ctrls-colorimetry.rst
> new file mode 100644
> index 000000000000..16d9ddadbab6
> --- /dev/null
> +++ b/Documentation/userspace-api/media/v4l/ext-ctrls-colorimetry.rst
> @@ -0,0 +1,88 @@
> +.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
> +
> +.. _colorimetry-controls:
> +
> +*****************************
> +Colorimetry Control Reference
> +*****************************
> +
> +Below are controls within the Colorimetry control class.
> +
> +Colorimetry Control IDs
> +-----------------------
> +
> +.. _colorimetry-control-id:
> +
> +``V4L2_CID_COLORIMETRY_CLASS (class)``
> + The Colorimetry class descriptor.
> +
> +``V4L2_CID_COLORIMETRY_HDR10_CLL_INFO (struct)``
> + The Content Light Level defines upper bounds for the nominal target
> + brightness light level of the pictures.
> +
> +.. c:type:: v4l2_ctrl_hdr10_cll_info
> +
> +.. cssclass:: longtable
> +
> +.. flat-table:: struct v4l2_ctrl_hdr10_cll_info
> + :header-rows: 0
> + :stub-columns: 0
> + :widths: 1 1 2
> +
> + * - __u16
> + - ``max_content_light_level``
> + - An upper bound on the maximum light level among all individual

An -> The
on -> for

> + samples for the pictures of coded video sequence, cd/m2. When

of -> of a

> + equal to 0 no such uppper bound is present.

uppper -> upper

> + * - __u16
> + - ``max_pic_average_light_level``
> + - An upper bound on the maximum average light level among the

An -> The
on -> for

> + samples for any individual picture of coded video sequence, cd/m2.

of -> of a

> + When equal to 0 no such uppper bound is present.

uppper -> upper

> +
> +``V4L2_CID_COLORIMETRY_HDR10_MASTERING_DISPLAY (struct)``
> + The mastering display defines the colour volume (the colour primaries,
> + white point and luminance range) of a display considered to be the
> + mastering display for current video content.

for -> for the

> +
> +.. c:type:: v4l2_ctrl_hdr10_mastering_display
> +
> +.. cssclass:: longtable
> +
> +.. flat-table:: struct v4l2_ctrl_hdr10_mastering_display
> + :header-rows: 0
> + :stub-columns: 0
> + :widths: 1 1 2
> +
> + * - __u16
> + - ``display_primaries_x[3]``
> + - Specifies the normalized x chromaticity coordinate of the colour
> + primary component c of the mastering display in increments of 0.00002.
> + For describing mastering display that use Red, Green and Blue colour

describing -> describing the
use -> uses

> + primaries, index value c equal to 0 correspond to Green primary, c

to Green -> to the Green
correspond -> corresponds

> + equal to 1 correspond to Blue primary and c equal to 2 correspond to

ditto

> + Red colour primary.
> + * - __u16
> + - ``display_primaries_y[3]``
> + - Specifies the normalized y chromaticity coordinate of the colour
> + primary component c of the mastering display in increments of 0.00002.
> + For describing mastering display that use Red, Green and Blue colour
> + primaries, index value c equal to 0 correspond to Green primary, c
> + equal to 1 correspond to Blue primary and c equal to 2 correspond to
> + Red colour primary.

ditto

> + * - __u16
> + - ``white_point_x``
> + - Specifies the normalized x chromaticity coordinate of the white
> + point of the mastering display in increments of 0.00002.
> + * - __u16
> + - ``white_point_y``
> + - Specifies the normalized y chromaticity coordinate of the white
> + point of the mastering display in increments of 0.00002.
> + * - __u32
> + - ``max_luminance``
> + - Specifies the nominal maximum display luminance of the mastering
> + display in units of 0.0001 cd/m2.
> + * - __u32
> + - ``min_luminance``
> + - specifies the nominal minimum display luminance of the mastering
> + display in units of 0.0001 cd/m2.
>

Regards,

Hans