1.13. Image Source Control Reference

The Image Source control class is intended for low-level control of image source devices such as image sensors. The devices feature an analogue to digital converter and a bus transmitter to transmit the image data out of the device.

1.13.1. Image Source Control IDs

V4L2_CID_IMAGE_SOURCE_CLASS (class)

The IMAGE_SOURCE class descriptor.

V4L2_CID_VBLANK (integer)

Vertical blanking. The idle period after every frame during which no image data is produced. The unit of vertical blanking is a line. Every line has length of the image width plus horizontal blanking at the pixel rate defined by V4L2_CID_PIXEL_RATE control in the same sub-device.

V4L2_CID_HBLANK (integer)

Horizontal blanking. The idle period after every line of image data during which no image data is produced. The unit of horizontal blanking is pixels.

V4L2_CID_ANALOGUE_GAIN (integer)

Analogue gain is gain affecting all colour components in the pixel matrix. The gain operation is performed in the analogue domain before A/D conversion.

V4L2_CID_TEST_PATTERN_RED (integer)

Test pattern red colour component.

V4L2_CID_TEST_PATTERN_GREENR (integer)

Test pattern green (next to red) colour component.

V4L2_CID_TEST_PATTERN_BLUE (integer)

Test pattern blue colour component.

V4L2_CID_TEST_PATTERN_GREENB (integer)

Test pattern green (next to blue) colour component.

V4L2_CID_UNIT_CELL_SIZE (struct)

This control returns the unit cell size in nanometers. The struct v4l2_area provides the width and the height in separate fields to take into consideration asymmetric pixels. This control does not take into consideration any possible hardware binning. The unit cell consists of the whole area of the pixel, sensitive and non-sensitive. This control is required for automatic calibration of sensors/cameras.

v4l2_area

struct v4l2_area

__u32	width	Width of the area.
__u32	height	Height of the area.