| .. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later | |
| .. c:namespace:: V4L | |
| .. _image-process-controls: | |
| ******************************* | |
| Image Process Control Reference | |
| ******************************* | |
| The Image Process control class is intended for low-level control of | |
| image processing functions. Unlike ``V4L2_CID_IMAGE_SOURCE_CLASS``, the | |
| controls in this class affect processing the image, and do not control | |
| capturing of it. | |
| .. _image-process-control-id: | |
| Image Process Control IDs | |
| ========================= | |
| ``V4L2_CID_IMAGE_PROC_CLASS (class)`` | |
| The IMAGE_PROC class descriptor. | |
| .. _v4l2-cid-link-freq: | |
| ``V4L2_CID_LINK_FREQ (integer menu)`` | |
| The fundamental frequency of the operating symbol rate (serial interfaces | |
| such as CSI-2) or the sampling rate (parallel interfaces such as DVP or | |
| Bt.565) of the data interface. For CSI-2, the frequency is equal to | |
| _1 / (2 * UI)_. | |
| .. _v4l2-cid-pixel-rate: | |
| ``V4L2_CID_PIXEL_RATE (64-bit integer)`` | |
| Pixel sampling rate in the device's pixel array. This control is | |
| read-only and its unit is pixels / second. | |
| Some devices use horizontal and vertical blanking to configure the frame | |
| rate. The frame rate can be calculated from the pixel rate, analogue crop | |
| rectangle as well as horizontal and vertical blanking. The pixel rate | |
| control may be present in a different sub-device than the blanking controls | |
| and the analogue crop rectangle configuration. | |
| The configuration of the frame rate is performed by selecting the desired | |
| horizontal and vertical blanking. The unit of this control is Hz. | |
| ``V4L2_CID_TEST_PATTERN (menu)`` | |
| Some capture/display/sensor devices have the capability to generate | |
| test pattern images. These hardware specific test patterns can be | |
| used to test if a device is working properly. | |
| ``V4L2_CID_DEINTERLACING_MODE (menu)`` | |
| The video deinterlacing mode (such as Bob, Weave, ...). The menu items are | |
| driver specific and are documented in :ref:`uapi-v4l-drivers`. | |
| ``V4L2_CID_DIGITAL_GAIN (integer)`` | |
| Digital gain is the value by which all colour components | |
| are multiplied by. Typically the digital gain applied is the | |
| control value divided by e.g. 0x100, meaning that to get no | |
| digital gain the control value needs to be 0x100. The no-gain | |
| configuration is also typically the default. |