[Interest] USB Webcams in Android?

[Jason H]

I'm wondering what it would take to get USB webcams working in Qt on Android. It seems that if the kernel already supports it, it will be listed as as /dev/v* device.

I'm also wondering what Qt needs to use the device? I plugged it in and it did not appear in QtMultimedia.availableCameras:  
[
  {"deviceId":"back","displayName":"Rear-facing camera","position":1,"orientation":270},
  {"deviceId":"front","displayName":"Front-facing camera","position":2,"orientation":90}
]

Additionally, it seems that many camera apps don't support USB cameras and USB camera apps don't support the built-in cameras. 
The only hint at what is going on is this line in logcat: 04-10 10:59:05.360 14692 14886 I USBMonitor: name=/dev/bus/usb/001/002,desc=86,busnum=1,devnum=2,rawDesc=[B at 6930dda


Many thanks!

Here's what my Android kernel is saying:
[ 2026.007529] PMI: smblib_vbus_regulator_enable: Enabling internal vbus regulator
[ 2026.014142] msm-dwc3 a800000.ssusb: DWC3 exited from low power mode
[ 2026.019444] xhci-hcd xhci-hcd.0.auto: xHCI Host Controller
[ 2026.019548] xhci-hcd xhci-hcd.0.auto: new USB bus registered, assigned bus number 1
[ 2026.026489] xhci-hcd xhci-hcd.0.auto: hcc params 0x0230fe65 hci version 0x110 quirks 0x00010010
[ 2026.026595] xhci-hcd xhci-hcd.0.auto: irq 732, io mem 0x0a800000
[ 2026.027069] usb usb1: New USB device found, idVendor=1d6b, idProduct=0002
[ 2026.027101] usb usb1: New USB device strings: Mfr=3, Product=2, SerialNumber=1
[ 2026.027130] usb usb1: Product: xHCI Host Controller
[ 2026.027156] usb usb1: Manufacturer: Linux 4.4.88-gda039c93611c xhci-hcd
[ 2026.027182] usb usb1: SerialNumber: xhci-hcd.0.auto
[ 2026.035180] hub 1-0:1.0: USB hub found
[ 2026.036400] hub 1-0:1.0: 1 port detected
[ 2026.037148] xhci-hcd xhci-hcd.0.auto: xHCI Host Controller
[ 2026.037195] xhci-hcd xhci-hcd.0.auto: new USB bus registered, assigned bus number 2
[ 2026.037435] usb usb2: We don't know the algorithms for LPM for this host, disabling LPM.
[ 2026.037767] usb usb2: New USB device found, idVendor=1d6b, idProduct=0003
[ 2026.037798] usb usb2: New USB device strings: Mfr=3, Product=2, SerialNumber=1
[ 2026.037825] usb usb2: Product: xHCI Host Controller
[ 2026.037851] usb usb2: Manufacturer: Linux 4.4.88-gda039c93611c xhci-hcd
[ 2026.037877] usb usb2: SerialNumber: xhci-hcd.0.auto
[ 2026.043081] hub 2-0:1.0: USB hub found
[ 2026.043804] hub 2-0:1.0: 1 port detected
[ 2026.342230] usb 1-1: new high-speed USB device number 2 using xhci-hcd
[ 2026.485458] usb 1-1: New USB device found, idVendor=a16f, idProduct=0304
[ 2026.485503] usb 1-1: New USB device strings: Mfr=2, Product=3, SerialNumber=0
[ 2026.485526] usb 1-1: Product: USB2.0 UVC PC Camera
[ 2026.485548] usb 1-1: Manufacturer: GenesysLogic Technology Co., Ltd.
[ 2026.545861] PMI: smblib_set_prop_use_external_vbus_output: VBUS output source: internal -> extern

walleye:/dev # ls -al v*
crw-rw---- 1 system camera 81, 128 1970-06-12 03:04 v4l-subdev0
crw-rw---- 1 system camera 81, 129 1970-06-12 03:04 v4l-subdev1
crw-rw---- 1 system camera 81, 138 1970-06-12 03:04 v4l-subdev10
crw-rw---- 1 system camera 81, 139 1970-06-12 03:04 v4l-subdev11
crw-rw---- 1 system camera 81, 140 1970-06-12 03:04 v4l-subdev12
crw-rw---- 1 system camera 81, 141 1970-06-12 03:04 v4l-subdev13
crw-rw---- 1 system camera 81, 142 1970-06-12 03:04 v4l-subdev14
crw-rw---- 1 system camera 81, 143 1970-06-12 03:04 v4l-subdev15
crw-rw---- 1 system camera 81, 144 1970-06-12 03:04 v4l-subdev16
crw-rw---- 1 system camera 81, 145 1970-06-12 03:04 v4l-subdev17
crw-rw---- 1 system camera 81, 146 1970-06-12 03:04 v4l-subdev18
crw-rw---- 1 system camera 81, 147 2018-04-10 09:47 v4l-subdev19
crw-rw---- 1 system camera 81, 130 1970-06-12 03:04 v4l-subdev2
crw-rw---- 1 system camera 81, 148 2018-04-10 09:47 v4l-subdev20
crw-rw---- 1 system camera 81, 131 1970-06-12 03:04 v4l-subdev3
crw-rw---- 1 system camera 81, 132 1970-06-12 03:04 v4l-subdev4
crw-rw---- 1 system camera 81, 133 1970-06-12 03:04 v4l-subdev5
crw-rw---- 1 system camera 81, 134 1970-06-12 03:04 v4l-subdev6
crw-rw---- 1 system camera 81, 135 1970-06-12 03:04 v4l-subdev7
crw-rw---- 1 system camera 81, 136 1970-06-12 03:04 v4l-subdev8
crw-rw---- 1 system camera 81, 137 1970-06-12 03:04 v4l-subdev9
crw------- 1 root   root   10,  95 1970-06-12 03:04 vga_arbiter
crw-rw---- 1 system camera 81,   0 1970-06-12 03:04 video0
crw-rw---- 1 system camera 81,   1 1970-06-12 03:04 video1
crw-rw---- 1 system camera 81,   2 1970-06-12 03:04 video2
crw-rw---- 1 system camera 81,   3 1970-06-12 03:04 video3
crw-rw---- 1 system camera 81,  32 1970-06-12 03:04 video32
crw-rw---- 1 system camera 81,  33 1970-06-12 03:04 video33
crw-rw---- 1 system camera 81,   4 2018-04-10 09:47 video4
crw-rw---- 1 system camera 81,   5 2018-04-10 09:47 video5
crw-rw-rw- 1 root   root   10,  47 1970-06-12 03:04 vndbinder