1 .. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
3 .. _image-process-controls:
5 *******************************
6 Image Process Control Reference
7 *******************************
9 The Image Process control class is intended for low-level control of
10 image processing functions. Unlike ``V4L2_CID_IMAGE_SOURCE_CLASS``, the
11 controls in this class affect processing the image, and do not control
15 .. _image-process-control-id:
17 Image Process Control IDs
18 =========================
20 ``V4L2_CID_IMAGE_PROC_CLASS (class)``
21 The IMAGE_PROC class descriptor.
23 .. _v4l2-cid-link-freq:
25 ``V4L2_CID_LINK_FREQ (integer menu)``
26 The frequency of the data bus (e.g. parallel or CSI-2).
28 .. _v4l2-cid-pixel-rate:
30 ``V4L2_CID_PIXEL_RATE (64-bit integer)``
31 Pixel sampling rate in the device's pixel array. This control is
32 read-only and its unit is pixels / second.
34 Some devices use horizontal and vertical balanking to configure the frame
35 rate. The frame rate can be calculated from the pixel rate, analogue crop
36 rectangle as well as horizontal and vertical blanking. The pixel rate
37 control may be present in a different sub-device than the blanking controls
38 and the analogue crop rectangle configuration.
40 The configuration of the frame rate is performed by selecting the desired
41 horizontal and vertical blanking. The unit of this control is Hz.
43 ``V4L2_CID_TEST_PATTERN (menu)``
44 Some capture/display/sensor devices have the capability to generate
45 test pattern images. These hardware specific test patterns can be
46 used to test if a device is working properly.
48 ``V4L2_CID_DEINTERLACING_MODE (menu)``
49 The video deinterlacing mode (such as Bob, Weave, ...). The menu items are
50 driver specific and are documented in :ref:`uapi-v4l-drivers`.
52 ``V4L2_CID_DIGITAL_GAIN (integer)``
53 Digital gain is the value by which all colour components
54 are multiplied by. Typically the digital gain applied is the
55 control value divided by e.g. 0x100, meaning that to get no
56 digital gain the control value needs to be 0x100. The no-gain
57 configuration is also typically the default.