$ dmesg |grep video
[Sat Sep 22 11:43:11 2018] uvcvideo: Found UVC 1.00 device Integrated Camera (1bcf:2c70)
[Sat Sep 22 11:43:11 2018] uvcvideo 2-8:1.0: Entity type for entity Extension 4 was not initialized!
[Sat Sep 22 11:43:11 2018] uvcvideo 2-8:1.0: Entity type for entity Extension 3 was not initialized!
[Sat Sep 22 11:43:11 2018] uvcvideo 2-8:1.0: Entity type for entity Processing 2 was not initialized!
[Sat Sep 22 11:43:11 2018] uvcvideo 2-8:1.0: Entity type for entity Camera 1 was not initialized!
[Sat Sep 22 11:43:11 2018] usbcore: registered new interface driver uvcvideo
$ lsusb
Bus 002 Device 004: ID 1bcf:2c70 Sunplus Innovation Technology Inc.
$ lsmod |grep uvc
uvcvideo 110592 1
videobuf2_vmalloc 16384 1 uvcvideo
videobuf2_v4l2 28672 1 uvcvideo
videobuf2_common 53248 2 videobuf2_v4l2,uvcvideo
videodev 212992 4 videobuf2_v4l2,uvcvideo,videobuf2_common
media 45056 2 videodev,uvcvideo
usbcore 294912 5 xhci_hcd,ehci_pci,uvcvideo,ehci_hcd,xhci_pci
$ ls -al /dev/video*
crw-rw----+ 1 root video 81, 0 Sep 22 11:43 /dev/video0
crw-rw----+ 1 root video 81, 1 Sep 22 11:43 /dev/video1
$ id
uid=1000(jb) gid=1000(jb) groups=1000(jb),10(wheel),91(video)
$ v4l2-ctl --list-devices
Integrated Camera: Integrated C (usb-0000:00:14.0-8):
/dev/video0
/dev/video1
$ xawtv
It works - Capture Window, webcam control light ON.
It does not work for Skype (webcam control light OFF).
Note: it works for Skype under Win 7.
SOLVED:
https://wiki.archlinux.org/index.php/webcam_setup
Use LD_PRELOAD.