| .. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later |
| |
| .. _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 frequency of the data bus (e.g. parallel or CSI-2). |
| |
| .. _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 balanking 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. |
