What you want I think is udev rules.
I'm on 12.04 so your mileage may vary, but here's an example:
You want to change switch /dev/video1 and /dev/video0. First get the info you need:
udevadm info -a -p $(udevadm info -q path -n /dev/video0)
udevadm info -a -p $(udevadm info -q path -n /dev/video1)
Copy both of those huge blocks of text into gedit
Mine looked like this:
looking at device '/devices/pci0000:00/0000:00:12.2/usb1/1-1/1-1:1.0/video4linux/video0':
KERNEL=="video0"
SUBSYSTEM=="video4linux"
DRIVER==""
ATTR{name}=="USB2.0 PC CAMERA"
ATTR{index}=="0"
looking at parent device '/devices/pci0000:00/0000:00:12.2/usb1/1-1/1-1:1.0':
KERNELS=="1-1:1.0"
SUBSYSTEMS=="usb"
DRIVERS=="uvcvideo"
ATTRS{bInterfaceNumber}=="00"
ATTRS{bAlternateSetting}==" 0"
ATTRS{bNumEndpoints}=="01"
ATTRS{bInterfaceClass}=="0e"
ATTRS{bInterfaceSubClass}=="01"
ATTRS{bInterfaceProtocol}=="00"
ATTRS{supports_autosuspend}=="1"
ATTRS{iad_bFirstInterface}=="00"
ATTRS{iad_bInterfaceCount}=="02"
ATTRS{iad_bFunctionClass}=="0e"
ATTRS{iad_bFunctionSubClass}=="03"
ATTRS{iad_bFunctionProtocol}=="00"
looking at parent device '/devices/pci0000:00/0000:00:12.2/usb1/1-1':
KERNELS=="1-1"
SUBSYSTEMS=="usb"
DRIVERS=="usb"
ATTRS{configuration}==""
ATTRS{bNumInterfaces}==" 4"
ATTRS{bConfigurationValue}=="1"
ATTRS{bmAttributes}=="80"
ATTRS{bMaxPower}=="320mA"
ATTRS{urbnum}=="5064"
ATTRS{idVendor}=="18ec"
ATTRS{idProduct}=="3299"
ATTRS{bcdDevice}=="0100"
ATTRS{bDeviceClass}=="ef"
ATTRS{bDeviceSubClass}=="02"
ATTRS{bDeviceProtocol}=="01"
ATTRS{bNumConfigurations}=="1"
ATTRS{bMaxPacketSize0}=="64"
ATTRS{speed}=="480"
ATTRS{busnum}=="1"
ATTRS{devnum}=="14"
ATTRS{devpath}=="1"
ATTRS{version}==" 2.00"
ATTRS{maxchild}=="0"
ATTRS{quirks}=="0x0"
ATTRS{avoid_reset_quirk}=="0"
ATTRS{authorized}=="1"
ATTRS{manufacturer}=="ARKMICRO"
ATTRS{product}=="USB2.0 PC CAMERA"
looking at parent device '/devices/pci0000:00/0000:00:12.2/usb1':
KERNELS=="usb1"
SUBSYSTEMS=="usb"
DRIVERS=="usb"
ATTRS{configuration}==""
ATTRS{bNumInterfaces}==" 1"
ATTRS{bConfigurationValue}=="1"
ATTRS{bmAttributes}=="e0"
ATTRS{bMaxPower}==" 0mA"
ATTRS{urbnum}=="324"
ATTRS{idVendor}=="1d6b"
ATTRS{idProduct}=="0002"
ATTRS{bcdDevice}=="0302"
ATTRS{bDeviceClass}=="09"
ATTRS{bDeviceSubClass}=="00"
ATTRS{bDeviceProtocol}=="00"
ATTRS{bNumConfigurations}=="1"
ATTRS{bMaxPacketSize0}=="64"
ATTRS{speed}=="480"
ATTRS{busnum}=="1"
ATTRS{devnum}=="1"
ATTRS{devpath}=="0"
ATTRS{version}==" 2.00"
ATTRS{maxchild}=="6"
ATTRS{quirks}=="0x0"
ATTRS{avoid_reset_quirk}=="0"
ATTRS{authorized}=="1"
ATTRS{manufacturer}=="Linux 3.2.0-22-generic ehci_hcd"
ATTRS{product}=="EHCI Host Controller"
ATTRS{serial}=="0000:00:12.2"
ATTRS{authorized_default}=="1"
looking at parent device '/devices/pci0000:00/0000:00:12.2':
KERNELS=="0000:00:12.2"
SUBSYSTEMS=="pci"
DRIVERS=="ehci_hcd"
ATTRS{vendor}=="0x1002"
ATTRS{device}=="0x4396"
ATTRS{subsystem_vendor}=="0x1043"
ATTRS{subsystem_device}=="0x8389"
ATTRS{class}=="0x0c0320"
ATTRS{irq}=="17"
ATTRS{local_cpus}=="00000000,00000000,00000000,00000000,00000000,00000000,00000000,0000000f"
ATTRS{local_cpulist}=="0-3"
ATTRS{numa_node}=="0"
ATTRS{dma_mask_bits}=="32"
ATTRS{consistent_dma_mask_bits}=="32"
ATTRS{broken_parity_status}=="0"
ATTRS{msi_bus}==""
ATTRS{companion}==""
ATTRS{uframe_periodic_max}=="100"
looking at parent device '/devices/pci0000:00':
KERNELS=="pci0000:00"
SUBSYSTEMS==""
DRIVERS==""
You're looking for the attributes from lsusb that match your camera:
SUBSYSTEMS=="usb"
ATTRS{idVendor}=="firsthalf"
ATTRS{idProduct}=="secondhalf"
Then as root you edit your /etc/udev/rules.d/25-video-device.rules
That name is relatively arbitrary. The number has to do with what sets get parsed first, but it pops up in a lot of udev google searches. Let's just use it.
Mine looks like:
SUBSYSTEMS=="usb", ATTRS{idVendor}=="18ec", ATTRS{idProduct}=="3298", NAME:="video0", OPTIONS:="link_priority=100"
SUBSYSTEMS=="usb", ATTRS{idVendor}=="090c", ATTRS{idProduct}=="c371", NAME:="video2"
Save the file
Some sources indicate as root service udev restart
, but I got a hard lock. So just reboot with it plugged in.
Now fire up anything that doesn't let you choose a video device. Since they're probably hard-wired to use /dev/video0, this should "just work".
For whatever reason, at least for me, it won't over-ride and displace the existing video0, it just creates two files(maybe by design). You could ln -sf /dev/video1 /dev/video0
. For me devices I specified this way seem to work. I tested with guvcview.
Congratulations, you just wrote a udev rule to overcome a hard-coded url.
You can specify to run commands at the ends of those udev rules too.
SUBSYSTEMS=="usb", ATTRS{idVendor}=="18ec", ATTRS{idProduct}=="3298", NAME:="video0", OPTIONS:="link_priority=100", RUN+="ln -sf /dev/video1 /dev/video0"
SUBSYSTEMS=="usb", ATTRS{idVendor}=="090c", ATTRS{idProduct}=="c371", NAME:="video2"
Now your USB video occupies /dev/video0 and /dev/video1. You don't lose your built-in either since now it's located at /dev/video2.