Troubleshoot USB Webcam in Linux
Sources:
- https://wiki.archlinux.org/title/Webcam_setup
- assign-webcam-to-a-specific-dev-video
Relevant:
Prerequisites:
apt-get install v4l-utils psmisc
Verify USB Connectivity
root@duo:~# lsusb
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 004: ID 0471:0815 Philips (or NXP) eHome Infrared Receiver
Bus 001 Device 009: ID 1bcf:28c4 Sunplus Innovation Technology Inc. FHD Camera Microphone
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
This gives:
- bus: 001
- device: 009
- vendor: 1bcf
- product: 28c4
| sudo echo “uvcvideo” | sudo tee /etc/modules-load.d/uvc.conf |
Verify the device
root@duo:~# udevadm info --attribute-walk /dev/bus/usb/001/009
Udevadm info starts with the device specified by the devpath and then
walks up the chain of parent devices. It prints for every device
found, all possible attributes in the udev rules key format.
A rule to match, can be composed by the attributes of the device
and the attributes from one single parent device.
looking at device '/devices/pci0000:00/0000:00:14.0/usb1/1-1':
KERNEL=="1-1"
SUBSYSTEM=="usb"
DRIVER=="usb"
ATTR{authorized}=="1"
ATTR{avoid_reset_quirk}=="0"
ATTR{bConfigurationValue}=="1"
ATTR{bDeviceClass}=="ef"
ATTR{bDeviceProtocol}=="01"
ATTR{bDeviceSubClass}=="02"
ATTR{bMaxPacketSize0}=="64"
ATTR{bMaxPower}=="500mA"
ATTR{bNumConfigurations}=="1"
ATTR{bNumInterfaces}==" 4"
ATTR{bcdDevice}=="0530"
ATTR{bmAttributes}=="80"
ATTR{busnum}=="1"
ATTR{configuration}==""
ATTR{devnum}=="9"
ATTR{devpath}=="1"
ATTR{idProduct}=="28c4"
ATTR{idVendor}=="1bcf"
ATTR{ltm_capable}=="no"
ATTR{manufacturer}=="SunplusIT Inc"
ATTR{maxchild}=="0"
ATTR{power/active_duration}=="63846332"
ATTR{power/async}=="enabled"
ATTR{power/autosuspend}=="2"
ATTR{power/autosuspend_delay_ms}=="2000"
ATTR{power/connected_duration}=="63846332"
ATTR{power/control}=="auto"
ATTR{power/level}=="auto"
ATTR{power/persist}=="1"
ATTR{power/runtime_active_kids}=="0"
ATTR{power/runtime_active_time}=="63846053"
ATTR{power/runtime_enabled}=="enabled"
ATTR{power/runtime_status}=="active"
ATTR{power/runtime_suspended_time}=="0"
ATTR{power/runtime_usage}=="1"
ATTR{product}=="FHD Camera Microphone"
ATTR{quirks}=="0x0"
ATTR{removable}=="removable"
ATTR{rx_lanes}=="1"
ATTR{serial}=="01.00.00"
ATTR{speed}=="480"
ATTR{tx_lanes}=="1"
ATTR{urbnum}=="364"
ATTR{version}==" 2.00"
looking at parent device '/devices/pci0000:00/0000:00:14.0/usb1':
KERNELS=="usb1"
SUBSYSTEMS=="usb"
DRIVERS=="usb"
ATTRS{authorized}=="1"
ATTRS{authorized_default}=="1"
ATTRS{avoid_reset_quirk}=="0"
ATTRS{bConfigurationValue}=="1"
ATTRS{bDeviceClass}=="09"
ATTRS{bDeviceProtocol}=="01"
ATTRS{bDeviceSubClass}=="00"
ATTRS{bMaxPacketSize0}=="64"
ATTRS{bMaxPower}=="0mA"
ATTRS{bNumConfigurations}=="1"
ATTRS{bNumInterfaces}==" 1"
ATTRS{bcdDevice}=="0515"
ATTRS{bmAttributes}=="e0"
ATTRS{busnum}=="1"
ATTRS{configuration}==""
ATTRS{devnum}=="1"
ATTRS{devpath}=="0"
ATTRS{idProduct}=="0002"
ATTRS{idVendor}=="1d6b"
ATTRS{interface_authorized_default}=="1"
ATTRS{ltm_capable}=="no"
ATTRS{manufacturer}=="Linux 5.15.83-1-pve xhci-hcd"
ATTRS{maxchild}=="16"
ATTRS{power/active_duration}=="68110804"
ATTRS{power/async}=="enabled"
ATTRS{power/autosuspend}=="0"
ATTRS{power/autosuspend_delay_ms}=="0"
ATTRS{power/connected_duration}=="68110804"
ATTRS{power/control}=="auto"
ATTRS{power/level}=="auto"
ATTRS{power/runtime_active_kids}=="2"
ATTRS{power/runtime_active_time}=="68110803"
ATTRS{power/runtime_enabled}=="enabled"
ATTRS{power/runtime_status}=="active"
ATTRS{power/runtime_suspended_time}=="0"
ATTRS{power/runtime_usage}=="0"
ATTRS{power/wakeup}=="disabled"
ATTRS{power/wakeup_abort_count}==""
ATTRS{power/wakeup_active}==""
ATTRS{power/wakeup_active_count}==""
ATTRS{power/wakeup_count}==""
ATTRS{power/wakeup_expire_count}==""
ATTRS{power/wakeup_last_time_ms}==""
ATTRS{power/wakeup_max_time_ms}==""
ATTRS{power/wakeup_total_time_ms}==""
ATTRS{product}=="xHCI Host Controller"
ATTRS{quirks}=="0x0"
ATTRS{removable}=="unknown"
ATTRS{rx_lanes}=="1"
ATTRS{serial}=="0000:00:14.0"
ATTRS{speed}=="480"
ATTRS{tx_lanes}=="1"
ATTRS{urbnum}=="304"
ATTRS{version}==" 2.00"
looking at parent device '/devices/pci0000:00/0000:00:14.0':
KERNELS=="0000:00:14.0"
SUBSYSTEMS=="pci"
DRIVERS=="xhci_hcd"
ATTRS{ari_enabled}=="0"
ATTRS{broken_parity_status}=="0"
ATTRS{class}=="0x0c0330"
ATTRS{consistent_dma_mask_bits}=="64"
ATTRS{d3cold_allowed}=="1"
ATTRS{dbc}=="disabled"
ATTRS{device}=="0xa2af"
ATTRS{dma_mask_bits}=="64"
ATTRS{driver_override}=="(null)"
ATTRS{enable}=="1"
ATTRS{index}=="2"
ATTRS{irq}=="132"
ATTRS{label}=="Onboard - Other"
ATTRS{local_cpulist}=="0-5"
ATTRS{local_cpus}=="3f"
ATTRS{msi_bus}=="1"
ATTRS{msi_irqs/132}=="msi"
ATTRS{numa_node}=="-1"
ATTRS{power/async}=="enabled"
ATTRS{power/control}=="on"
ATTRS{power/runtime_active_kids}=="1"
ATTRS{power/runtime_active_time}=="68111751"
ATTRS{power/runtime_enabled}=="forbidden"
ATTRS{power/runtime_status}=="active"
ATTRS{power/runtime_suspended_time}=="0"
ATTRS{power/runtime_usage}=="2"
ATTRS{power/wakeup}=="enabled"
ATTRS{power/wakeup_abort_count}=="0"
ATTRS{power/wakeup_active}=="0"
ATTRS{power/wakeup_active_count}=="0"
ATTRS{power/wakeup_count}=="0"
ATTRS{power/wakeup_expire_count}=="0"
ATTRS{power/wakeup_last_time_ms}=="0"
ATTRS{power/wakeup_max_time_ms}=="0"
ATTRS{power/wakeup_total_time_ms}=="0"
ATTRS{power_state}=="D0"
ATTRS{revision}=="0x00"
ATTRS{subsystem_device}=="0xa2af"
ATTRS{subsystem_vendor}=="0x1849"
ATTRS{vendor}=="0x8086"
looking at parent device '/devices/pci0000:00':
KERNELS=="pci0000:00"
SUBSYSTEMS==""
DRIVERS==""
ATTRS{power/async}=="enabled"
ATTRS{power/control}=="auto"
ATTRS{power/runtime_active_kids}=="10"
ATTRS{power/runtime_active_time}=="0"
ATTRS{power/runtime_enabled}=="disabled"
ATTRS{power/runtime_status}=="unsupported"
ATTRS{power/runtime_suspended_time}=="0"
ATTRS{power/runtime_usage}=="0"
ATTRS{waiting_for_supplier}=="0"
Verify and list v4l devices
By ID:
> ls -la /dev/v4l/by-id/
total 0
drwxr-xr-x 2 root root 80 Jan 19 10:34 .
drwxr-xr-x 4 root root 80 Jan 19 10:34 ..
lrwxrwxrwx 1 root root 12 Jan 19 10:34 usb-CN0K0KM8LOG007BG018TA00_Integrated_Webcam_HD_200901010001-video-index0 -> ../../video2
lrwxrwxrwx 1 root root 12 Jan 19 10:34 usb-CN0K0KM8LOG007BG018TA00_Integrated_Webcam_HD_200901010001-video-index1 -> ../../video1
By path:
> ls -la /dev/v4l/by-path
total 0
drwxr-xr-x 2 root root 120 Jan 19 10:34 .
drwxr-xr-x 4 root root 80 Jan 19 10:34 ..
lrwxrwxrwx 1 root root 12 Jan 19 10:34 pci-0000:00:14.0-usb-0:5:1.0-video-index0 -> ../../video0
lrwxrwxrwx 1 root root 12 Jan 19 10:34 pci-0000:00:14.0-usb-0:5:1.0-video-index1 -> ../../video1
lrwxrwxrwx 1 root root 12 Jan 19 10:34 pci-0000:00:14.0-usb-0:5:1.2-video-index0 -> ../../video2
lrwxrwxrwx 1 root root 12 Jan 19 10:34 pci-0000:00:14.0-usb-0:5:1.2-video-index1 -> ../../video3
Or:
> ls -1 /dev/video*
/dev/video1
/dev/video2
Or just:
v4l2-ctl --list-devices
List Native Video Formats for the Device
Use:
v4l2-ctl --list-formats-ext --device /dev/video1
e.g., for a default device /dev/video0:
root@duo:~# v4l2-ctl --list-formats-ext
ioctl: VIDIOC_ENUM_FMT
Type: Video Capture
[0]: 'MJPG' (Motion-JPEG, compressed)
Size: Discrete 640x480
Interval: Discrete 0.033s (30.000 fps)
Size: Discrete 1600x896
Interval: Discrete 0.033s (30.000 fps)
Size: Discrete 1280x720
Interval: Discrete 0.033s (30.000 fps)
Size: Discrete 1024x576
Interval: Discrete 0.033s (30.000 fps)
Size: Discrete 800x600
Interval: Discrete 0.033s (30.000 fps)
Size: Discrete 800x480
Interval: Discrete 0.033s (30.000 fps)
Size: Discrete 640x360
Interval: Discrete 0.033s (30.000 fps)
Size: Discrete 424x240
Interval: Discrete 0.033s (30.000 fps)
Size: Discrete 352x288
Interval: Discrete 0.033s (30.000 fps)
Size: Discrete 1920x1080
Interval: Discrete 0.033s (30.000 fps)
[1]: 'YUYV' (YUYV 4:2:2)
Size: Discrete 640x480
Interval: Discrete 0.033s (30.000 fps)
Size: Discrete 1600x896
Interval: Discrete 0.133s (7.500 fps)
Size: Discrete 1280x720
Interval: Discrete 0.100s (10.000 fps)
Size: Discrete 1024x576
Interval: Discrete 0.100s (10.000 fps)
Size: Discrete 800x600
Interval: Discrete 0.067s (15.000 fps)
Size: Discrete 800x480
Interval: Discrete 0.040s (25.000 fps)
Size: Discrete 640x360
Interval: Discrete 0.033s (30.000 fps)
Size: Discrete 424x240
Interval: Discrete 0.033s (30.000 fps)
Size: Discrete 352x288
Interval: Discrete 0.033s (30.000 fps)
Size: Discrete 1920x1080
Interval: Discrete 0.200s (5.000 fps)
List All the Camera Capabilities
For a default video device /dev/video0:
root@duo:~# v4l2-ctl --all
Driver Info:
Driver name : uvcvideo
Card type : FHD Camera Microphone: FHD Came
Bus info : usb-0000:00:14.0-11
Driver version : 5.15.83
Capabilities : 0x84a00001
Video Capture
Metadata Capture
Streaming
Extended Pix Format
Device Capabilities
Device Caps : 0x04200001
Video Capture
Streaming
Extended Pix Format
Media Driver Info:
Driver name : uvcvideo
Model : FHD Camera Microphone: FHD Came
Serial : 01.00.00
Bus info : usb-0000:00:14.0-11
Media version : 5.15.83
Hardware revision: 0x00000530 (1328)
Driver version : 5.15.83
Interface Info:
ID : 0x03000002
Type : V4L Video
Entity Info:
ID : 0x00000001 (1)
Name : FHD Camera Microphone: FHD Came
Function : V4L2 I/O
Flags : default
Pad 0x01000007 : 0: Sink
Link 0x02000013: from remote pad 0x100000a of entity 'Extension 4': Data, Enabled, Immutable
Priority: 2
Video input : 0 (Camera 1: ok)
Format Video Capture:
Width/Height : 800/600
Pixel Format : 'MJPG' (Motion-JPEG)
Field : None
Bytes per Line : 0
Size Image : 960000
Colorspace : sRGB
Transfer Function : Rec. 709
YCbCr/HSV Encoding: ITU-R 601
Quantization : Default (maps to Full Range)
Flags :
Crop Capability Video Capture:
Bounds : Left 0, Top 0, Width 800, Height 600
Default : Left 0, Top 0, Width 800, Height 600
Pixel Aspect: 1/1
Selection Video Capture: crop_default, Left 0, Top 0, Width 800, Height 600, Flags:
Selection Video Capture: crop_bounds, Left 0, Top 0, Width 800, Height 600, Flags:
Streaming Parameters Video Capture:
Capabilities : timeperframe
Frames per second: 30.000 (30/1)
Read buffers : 0
brightness 0x00980900 (int) : min=-64 max=64 step=1 default=0 value=0
contrast 0x00980901 (int) : min=0 max=95 step=1 default=1 value=1
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_temperature_auto 0x0098090c (bool) : default=1 value=1
gamma 0x00980910 (int) : min=100 max=300 step=1 default=100 value=100
power_line_frequency 0x00980918 (menu) : min=0 max=2 default=1 value=1
0: Disabled
1: 50 Hz
2: 60 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=1 step=1 default=1 value=1
exposure_auto 0x009a0901 (menu) : min=0 max=3 default=3 value=3
1: Manual Mode
3: Aperture Priority Mode
exposure_absolute 0x009a0902 (int) : min=3 max=2047 step=1 default=166 value=166 flags=inactive
focus_absolute 0x009a090a (int) : min=0 max=1023 step=1 default=0 value=292 flags=inactive
focus_auto 0x009a090c (bool) : default=0 value=1
List All the Camera Controls
root@duo:~# v4l2-ctl -d /dev/video0 --list-ctrls
brightness 0x00980900 (int) : min=-64 max=64 step=1 default=0 value=0
contrast 0x00980901 (int) : min=0 max=95 step=1 default=1 value=1
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_temperature_auto 0x0098090c (bool) : default=1 value=1
gamma 0x00980910 (int) : min=100 max=300 step=1 default=100 value=100
power_line_frequency 0x00980918 (menu) : min=0 max=2 default=1 value=1
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=1 step=1 default=1 value=1
exposure_auto 0x009a0901 (menu) : min=0 max=3 default=3 value=3
exposure_absolute 0x009a0902 (int) : min=3 max=2047 step=1 default=166 value=166 flags=inactive
focus_absolute 0x009a090a (int) : min=0 max=1023 step=1 default=0 value=300 flags=inactive
focus_auto 0x009a090c (bool) : default=0 value=1
Adjust the Camera Controls
v4l2-ctl \
--set-ctrl=power_line_frequency=2 \
--set-ctrl=backlight_compensation=0 \
--set-ctrl=exposure_auto=1 \
--set-ctrl=exposure_absolute=166 \
--set-ctrl=focus_auto=0 \
--set-ctrl=white_balance_temperature_auto=0 \
--set-ctrl=focus_absolute=300