uvcdynctrl is a command-line tool that allows users to manage dynamic controls on their UVC (USB Video Class) compliant webcams using the uvcvideo driver. It is a part of the libwebcam library, which provides a collection of tools and libraries for working with webcams in Linux-based operating systems.
Dynamic controls refer to the various settings that can be adjusted on a webcam while it is in use, such as brightness, contrast, saturation, sharpness, and white balance. These settings are not fixed and can be changed by the user to achieve the desired image quality. The uvcdynctrl tool provides a way for users to view and adjust these settings from the command line.
uvcdynctrl can be used to list the available controls on a webcam, get and set their values, and save and load control configurations to and from files. It supports a wide range of controls, including standard UVC controls as well as vendor-specific controls.
To use uvcdynctrl, users first need to make sure that the uvcvideo driver is loaded and that their webcam is connected and recognized by the system. They can then run uvcdynctrl -l to list the available controls on their webcam. This will output a list of control names and IDs, along with their current values and ranges.
Users can then use the uvcdynctrl -s command to set the value of a control. For example, to set the brightness of a webcam to 50%, users would run the following command:
# uvcdynctrl -s "Brightness" 50
Users can also save the current control configuration to a file using the uvcdynctrl –save command, and load a saved configuration using the uvcdynctrl –load command.
uvcdynctrl Command Examples
1. List all available cameras:
# uvcdynctrl -l
2. Specify the device to use (defaults to `video0`):
# uvcdynctrl -d device_name
3. List available controls:
# uvcdynctrl -c
4. Set a new control value (for negative values, add — before {{-value}}):
# uvcdynctrl -s control_name value
5. Get the current control value:
# uvcdynctrl -g control_name
6. Save the state of the current controls to a file:
# uvcdynctrl -W filename
7. Load the state of the controls from a file:
# uvcdynctrl -L filename
Summary
Overall, uvcdynctrl is a powerful tool for managing webcam controls from the command line, and can be useful for both casual users and developers working on webcam-related applications.