1.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later 2 3.. _image-process-controls: 4 5******************************* 6Image Process Control Reference 7******************************* 8 9The Image Process control class is intended for low-level control of 10image processing functions. Unlike ``V4L2_CID_IMAGE_SOURCE_CLASS``, the 11controls in this class affect processing the image, and do not control 12capturing of it. 13 14 15.. _image-process-control-id: 16 17Image Process Control IDs 18========================= 19 20``V4L2_CID_IMAGE_PROC_CLASS (class)`` 21 The IMAGE_PROC class descriptor. 22 23``V4L2_CID_LINK_FREQ (integer menu)`` 24 Data bus frequency. Together with the media bus pixel code, bus type 25 (clock cycles per sample), the data bus frequency defines the pixel 26 rate (``V4L2_CID_PIXEL_RATE``) in the pixel array (or possibly 27 elsewhere, if the device is not an image sensor). The frame rate can 28 be calculated from the pixel clock, image width and height and 29 horizontal and vertical blanking. While the pixel rate control may 30 be defined elsewhere than in the subdev containing the pixel array, 31 the frame rate cannot be obtained from that information. This is 32 because only on the pixel array it can be assumed that the vertical 33 and horizontal blanking information is exact: no other blanking is 34 allowed in the pixel array. The selection of frame rate is performed 35 by selecting the desired horizontal and vertical blanking. The unit 36 of this control is Hz. 37 38``V4L2_CID_PIXEL_RATE (64-bit integer)`` 39 Pixel rate in the source pads of the subdev. This control is 40 read-only and its unit is pixels / second. 41 42``V4L2_CID_TEST_PATTERN (menu)`` 43 Some capture/display/sensor devices have the capability to generate 44 test pattern images. These hardware specific test patterns can be 45 used to test if a device is working properly. 46 47``V4L2_CID_DEINTERLACING_MODE (menu)`` 48 The video deinterlacing mode (such as Bob, Weave, ...). The menu items are 49 driver specific and are documented in :ref:`uapi-v4l-drivers`. 50 51``V4L2_CID_DIGITAL_GAIN (integer)`` 52 Digital gain is the value by which all colour components 53 are multiplied by. Typically the digital gain applied is the 54 control value divided by e.g. 0x100, meaning that to get no 55 digital gain the control value needs to be 0x100. The no-gain 56 configuration is also typically the default. 57