1.23. Colorimetry Control Reference

The Colorimetry class includes controls for High Dynamic Range imaging for representing colors in digital images and video. The controls should be used for video and image encoding and decoding as well as in HDMI receivers and transmitters.

1.23.1. Colorimetry Control IDs

V4L2_CID_COLORIMETRY_CLASS (class)

The Colorimetry class descriptor. Calling ioctls VIDIOC_QUERYCTRL, VIDIOC_QUERY_EXT_CTRL and VIDIOC_QUERYMENU for this control will return a description of this control class.

V4L2_CID_COLORIMETRY_HDR10_CLL_INFO (struct)

The Content Light Level defines upper bounds for the nominal target brightness light level of the pictures.

type v4l2_ctrl_hdr10_cll_info

struct v4l2_ctrl_hdr10_cll_info

__u16	max_content_light_level	The upper bound for the maximum light level among all individual samples for the pictures of a video sequence, cd/m2. When equal to 0 no such upper bound is present.
__u16	max_pic_average_light_level	The upper bound for the maximum average light level among the samples for any individual picture of a video sequence, cd/m2. When equal to 0 no such upper bound is present.

V4L2_CID_COLORIMETRY_HDR10_MASTERING_DISPLAY (struct)

The mastering display defines the color volume (the color primaries, white point and luminance range) of a display considered to be the mastering display for the current video content.

type v4l2_ctrl_hdr10_mastering_display

struct v4l2_ctrl_hdr10_mastering_display

__u16	display_primaries_x[3]	Specifies the normalized x chromaticity coordinate of the color primary component c of the mastering display in increments of 0.00002. For describing the mastering display that uses Red, Green and Blue color primaries, index value c equal to 0 corresponds to the Green primary, c equal to 1 corresponds to Blue primary and c equal to 2 corresponds to the Red color primary.
__u16	display_primaries_y[3]	Specifies the normalized y chromaticity coordinate of the color primary component c of the mastering display in increments of 0.00002. For describing the mastering display that uses Red, Green and Blue color primaries, index value c equal to 0 corresponds to the Green primary, c equal to 1 corresponds to Blue primary and c equal to 2 corresponds to Red color primary.
__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.