Auto exposure and other parameter names

[javieryu]

Some of the parameters for my device seem to have names that are slightly different than those set using this library. For instance, the ros parameter for autoexposure is set using the device control exposure_auto, but for my device it is auto_exposure according to v4l2-ctl --device=0 --all. This seems to result in a outcome where the autoexposure setting does not change anything when I set it in the params file or with ros2 param set ....

Output from v4l2-ctl --device=0 --all:

Result when running ros2 run usb_cam usb_cam_node_exe --ros-args --params-file params.yaml:

It seems like the naming conventions that is different for my camera/drivers? So far my workaround is to use the v4l2-ctl --device=0 --set-ctrl=... command after running the usb_cam node. Is there a better way to do this?

[flynneva]

@javieryu thanks for reporting this! I'll look into it and circle back this weekend.

[javieryu]

Great, I forked and changed the parameter name strings in UsbCamNode::set_v4l2_params() to match the outputs of v4l2-ctl, and that seems to have fixed my problems. I'm assuming that these names are different on each camera depending on the drivers.

For reference here are the camera specs:

Is the plan to eventually automatically discover the camera parameter names?

[TZECHIN6]

Seem i am also running into this as well:

User Controls

                     brightness 0x00980900 (int)    : min=-64 max=64 step=1 default=0 value=50
                       contrast 0x00980901 (int)    : min=0 max=95 step=1 default=0 value=0
                     saturation 0x00980902 (int)    : min=0 max=100 step=1 default=64 value=64
                            hue 0x00980903 (int)    : min=-2000 max=2000 step=1 default=0 value=0
        white_balance_automatic 0x0098090c (bool)   : default=1 value=1
                          gamma 0x00980910 (int)    : min=100 max=300 step=1 default=100 value=100
                           gain 0x00980913 (int)    : min=1 max=8 step=1 default=1 value=1
           power_line_frequency 0x00980918 (menu)   : min=0 max=2 default=2 value=1 (50 Hz)
      white_balance_temperature 0x0098091a (int)    : min=2800 max=6500 step=1 default=4600 value=4600 flags=inactive
                      sharpness 0x0098091b (int)    : min=1 max=7 step=1 default=2 value=2
         backlight_compensation 0x0098091c (int)    : min=0 max=3 step=1 default=3 value=3

Camera Controls

                  auto_exposure 0x009a0901 (menu)   : min=0 max=3 default=3 value=3 (Aperture Priority Mode)
         exposure_time_absolute 0x009a0902 (int)    : min=9 max=625 step=1 default=157 value=157 flags=inactive
     exposure_dynamic_framerate 0x009a0903 (bool)   : default=0 value=1

my v4l2-ctl version is 1.22.1

[flynneva]

Is the plan to eventually automatically discover the camera parameter names?

@javieryu this would be an awesome awesome feature! Just not sure how to implement it 😅 PR's / implementation ideas welcome 🙏🏼

[twdragon]

@flynneva @javieryu I am working now on it, as it was already implemented in ROS 1 branch. Hope to complete and create a PR soon!

[TZECHIN6]

@twdragon thanks for your contribution, I look forward to your PR

[nickswalker]

Just hit this too. It would be nice for parameters that fail to set to print to ROS_ERROR. I missed the error output from the v4l2-ctl command because I was running the node as part of a launch file.

We hardcoded our parameters in a fork here for the time being: https://github.com/hcrlab/usb_cam/

Our camera's parameters (teleop fisheye cameras from Hello Robot Stretch, in case others are searching):

User Controls

                     brightness 0x00980900 (int)    : min=-64 max=64 step=1 default=0 value=50
                       contrast 0x00980901 (int)    : min=0 max=100 step=1 default=40 value=100
                     saturation 0x00980902 (int)    : min=0 max=128 step=1 default=64 value=128
                            hue 0x00980903 (int)    : min=-180 max=180 step=1 default=0 value=0
        white_balance_automatic 0x0098090c (bool)   : default=1 value=1
                          gamma 0x00980910 (int)    : min=100 max=500 step=1 default=300 value=100
                           gain 0x00980913 (int)    : min=0 max=128 step=1 default=64 value=10
           power_line_frequency 0x00980918 (menu)   : min=0 max=2 default=1 value=2 (60 Hz)
      white_balance_temperature 0x0098091a (int)    : min=2800 max=6500 step=10 default=4600 value=4200 flags=inactive
                      sharpness 0x0098091b (int)    : min=0 max=100 step=1 default=56 value=45
         backlight_compensation 0x0098091c (int)    : min=0 max=2 step=1 default=0 value=0

Camera Controls

                  auto_exposure 0x009a0901 (menu)   : min=0 max=3 default=3 value=3 (Aperture Priority Mode)
         exposure_time_absolute 0x009a0902 (int)    : min=1 max=10000 step=1 default=166 value=10000 flags=inactive
     exposure_dynamic_framerate 0x009a0903 (bool)   : default=0 value=0
                   pan_absolute 0x009a0908 (int)    : min=-57600 max=57600 step=3600 default=0 value=0
                  tilt_absolute 0x009a0909 (int)    : min=-43200 max=43200 step=3600 default=0 value=0
                  zoom_absolute 0x009a090d (int)    : min=0 max=3 step=1 default=0 value=0