ext-ctrls-colorimetry.rst

 1.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
 2.. c:namespace:: V4L
 3
 4.. _colorimetry-controls:
 5
 6*****************************
 7Colorimetry Control Reference
 8*****************************
 9
10The Colorimetry class includes controls for High Dynamic Range
11imaging for representing colors in digital images and video. The
12controls should be used for video and image encoding and decoding
13as well as in HDMI receivers and transmitters.
14
15Colorimetry Control IDs
16-----------------------
17
18.. _colorimetry-control-id:
19
20``V4L2_CID_COLORIMETRY_CLASS (class)``
21    The Colorimetry class descriptor. Calling
22    :ref:`VIDIOC_QUERYCTRL` for this control will
23    return a description of this control class.
24
25``V4L2_CID_COLORIMETRY_HDR10_CLL_INFO (struct)``
26    The Content Light Level defines upper bounds for the nominal target
27    brightness light level of the pictures.
28
29.. c:type:: v4l2_ctrl_hdr10_cll_info
30
31.. cssclass:: longtable
32
33.. flat-table:: struct v4l2_ctrl_hdr10_cll_info
34    :header-rows:  0
35    :stub-columns: 0
36    :widths:       1 1 2
37
38    * - __u16
39      - ``max_content_light_level``
40      - The upper bound for the maximum light level among all individual
41        samples for the pictures of a video sequence, cd/m\ :sup:`2`.
42        When equal to 0 no such upper bound is present.
43    * - __u16
44      - ``max_pic_average_light_level``
45      - The upper bound for the maximum average light level among the
46        samples for any individual picture of a video sequence,
47        cd/m\ :sup:`2`. When equal to 0 no such upper bound is present.
48
49``V4L2_CID_COLORIMETRY_HDR10_MASTERING_DISPLAY (struct)``
50    The mastering display defines the color volume (the color primaries,
51    white point and luminance range) of a display considered to be the
52    mastering display for the current video content.
53
54.. c:type:: v4l2_ctrl_hdr10_mastering_display
55
56.. cssclass:: longtable
57
58.. flat-table:: struct v4l2_ctrl_hdr10_mastering_display
59    :header-rows:  0
60    :stub-columns: 0
61    :widths:       1 1 2
62
63    * - __u16
64      - ``display_primaries_x[3]``
65      - Specifies the normalized x chromaticity coordinate of the color
66        primary component c of the mastering display in increments of 0.00002.
67        For describing the mastering display that uses Red, Green and Blue
68        color primaries, index value c equal to 0 corresponds to the Green
69        primary, c equal to 1 corresponds to Blue primary and c equal to 2
70        corresponds to the Red color primary.
71    * - __u16
72      - ``display_primaries_y[3]``
73      - Specifies the normalized y chromaticity coordinate of the color
74        primary component c of the mastering display in increments of 0.00002.
75        For describing the mastering display that uses Red, Green and Blue
76        color primaries, index value c equal to 0 corresponds to the Green
77        primary, c equal to 1 corresponds to Blue primary and c equal to 2
78        corresponds to Red color primary.
79    * - __u16
80      - ``white_point_x``
81      - Specifies the normalized x chromaticity coordinate of the white
82        point of the mastering display in increments of 0.00002.
83    * - __u16
84      - ``white_point_y``
85      - Specifies the normalized y chromaticity coordinate of the white
86        point of the mastering display in increments of 0.00002.
87    * - __u32
88      - ``max_luminance``
89      - Specifies the nominal maximum display luminance of the mastering
90        display in units of 0.0001 cd/m\ :sup:`2`.
91    * - __u32
92      - ``min_luminance``
93      - specifies the nominal minimum display luminance of the mastering
94        display in units of 0.0001 cd/m\ :sup:`2`.