Find video device web cam uses

[clickit]

When I run apps like mplayer to use my web cam it uses /dev/video#. For reason unknown to me this number changes and is usually either 1 or 0. I have looked on the Internet after struggling to find how to know which /dev/video device is used. So far I can only presume I have used the wrong terms to find how to determine which device the web cam is using. Can someone help me?

[Kloschüssel]

who does provide you with the /dev/video device? usually this is a driver decision and thus it may be configurable once you found out who the driver is.

[clickit]

The device /dev/video is found in the directory /dev and is provided in most Linux distros.
I have no information on how one would manually assign a device to hardware. I believe this is done during booting which I will stay away from with all dispatch.
There are commands like lsusb, lspci, etc which list modules and hardware. I found cat /proc/asound/cards lists the sound and video cards/hardware but have not found a command which lists devices and cards. I have bt787, v8235, and camera cards but depending (haven't validated this yet) whether the HV7131R is detected or not seems to dictate whether /dev/video0 is used by the camera or if it is /dev/video1. I would like a command or one I can build to show the card vs device assignments.
Hope this helps.

[Kloschüssel]

lspci should do all you need?

[GNU-Fan]

Isn't that determined by the udev daemon?

You plug in the hardware and udev looks into some config file what dev node to create.

[clickit]

lspci yields:
00:00.0 Host bridge: VIA Technologies, Inc. VT8377 [KT400/KT600 AGP] Host Bridge
00:01.0 PCI bridge: VIA Technologies, Inc. VT8235 PCI Bridge
00:06.0 Multimedia video controller: Brooktree Corporation Bt878 Video Capture (rev 11)
00:06.1 Multimedia controller: Brooktree Corporation Bt878 Audio Capture (rev 11)
00:10.0 USB Controller: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller (rev 80)
00:10.1 USB Controller: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller (rev 80)
00:10.2 USB Controller: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller (rev 80)
00:10.3 USB Controller: VIA Technologies, Inc. USB 2.0 (rev 82)
00:11.0 ISA bridge: VIA Technologies, Inc. VT8235 ISA Bridge
00:11.1 IDE interface: VIA Technologies, Inc. VT82C586A/B/VT82C686/A/B/VT823x/A/C PIPC Bus Master IDE (rev 06)
00:11.5 Multimedia audio controller: VIA Technologies, Inc. VT8233/A/8235/8237 AC97 Audio Controller (rev 50)
00:12.0 Ethernet controller: VIA Technologies, Inc. VT6102 [Rhine-II] (rev 74)
01:00.0 VGA compatible controller: nVidia Corporation NV17 [GeForce4 MX 440] (rev a3)
I don't see where video0 or video1 occur?

Thank U GNU-Fan!! Your comment seems on to it, but on my system the rules in the appropriate directory were all for CDROM (seems strange). I can at least try those terms in a search to see where that leads unless you have more info.