Output from v4l2-ctl -l:

User Controls

brightness 0x00980900 (int) : min=0 max=255 step=1 default=128 value=128 flags=slider contrast 0x00980901 (int) : min=0 max=255 step=1 default=128 value=128 flags=slider gamma 0x00980910 (int) : min=1 max=6 step=1 default=3 value=3 flags=slider gain_automatic 0x00980912 (bool) : default=1 value=1 power_line_frequency 0x00980918 (menu) : min=0 max=2 default=0 value=0 sharpness 0x0098091b (int) : min=0 max=3 step=1 default=2 value=2 flags=slider

JPEG Compression Controls

compression_quality 0x009d0903 (int) : min=50 max=87 step=1 default=75 value=75

Output from v4l2-ctl -D:

Driver Info (not using libv4l2): Driver name : gspca_zc3xx Card type : USB Camera (041e:4051) Bus info : usb-0000:00:1d.3-1 Driver version: 4.15.18 Capabilities : 0x85200001 Video Capture Read/Write Streaming Extended Pix Format Device Capabilities Device Caps : 0x05200001 Video Capture Read/Write Streaming Extended Pix Format

Maybe "(not using libv4l2):" is my problem? Do I need a webcam app that specifically supports gspca? Anyway, I added myself to the 'video' group and ran Cheese. Since I was already in the terminal, I ran Cheese from the command line instead of from the GUI, like I usually do, and I was rewarded with some extra output (editing out some irrelevant lines):

Xlib: extension "RANDR" missing on display ":0". (cheese:8484): cheese-CRITICAL **: 10:26:20.051: cheese_camera_device_get_name: assertion 'CHEESE_IS_CAMERA_DEVICE (device)' failed

Cheese still didn't find a video device, and I got the same results running it as root. On Thu, Aug 8, 2019 at 4:59 PM John Stoffel <john@stoffel.org> wrote:

...

...

...

...

...

"Richard" == Richard Klein <rich@richardklein.org> writes:

Richard> Hmm... Richard> From lsusb: Richard> Bus 005 Device 003: ID 041e:4051 Creative Technology, Ltd Live! Cam Notebook Pro [VF0250]

So it sees it ok as a USB device

Richard> And from v4l2-ctl: Richard> USB Camera (041e:4051) (usb-0000:00:1d.3-1): Richard> /dev/video0

And it finds it properly. Maybe you can do:

v4l2-ctl -l /dev/video0

and see what controls is offers. Or try the -D option. See the man page for things to try.

Richard> But the webcam app I installed (Cheese) detects no device.

Did you check the permissions of /dev/video? Does 'cheese' have the permissions to open the file? Try running as root, or adding your account to the 'video' group.

John