当我将相机插入 Linux 时，我会得到 2 个设备/dev/video0，/dev/video1
为什么会发生这种情况，这正常吗？奇数设备不工作。 /dev/v4l/by-path 看起来像这样：
lrwxrwxrwx 1 root root 12 dets 15 01:29 pci-0000:00:14.0-usb-0:14:1.0-video-index0 -> ../../video0
lrwxrwxrwx 1 root root 12 dets 15 01:29 pci-0000:00:14.0-usb-0:14:1.0-video-index1 -> ../../video1
/dev/v4l/by-id 看起来像这样：
lrwxrwxrwx 1 root root 12 dets 15 01:29 usb-_Webcam_C170-video-index0 -> ../../video0
lrwxrwxrwx 1 root root 12 dets 15 01:29 usb-_Webcam_C170-video-index1 -> ../../video1
我用 2 台计算机（Kubuntu 18.10）和 4 个不同的摄像头对其进行了测试。它总是制造 2 个设备。
编辑添加的 dmesg 输出：
[118541.028706] usb 1-14: new high-speed USB device number 12 using xhci_hcd
[118541.254215] usb 1-14: New USB device found, idVendor=046d, idProduct=082b, bcdDevice=28.25
[118541.254221] usb 1-14: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[118541.254225] usb 1-14: Product: Webcam C170
[118541.254229] usb 1-14: Manufacturer:
[118541.310835] media: Linux media interface: v0.10
[118541.323429] videodev: Linux video capture interface: v2.00
[118541.332766] usbcore: registered new interface driver snd-usb-audio
[118541.334867] uvcvideo: Found UVC 1.00 device Webcam C170 (046d:082b)
[118541.354970] uvcvideo 1-14:1.0: Entity type for entity Processing 2 was not initialized!
[118541.354971] uvcvideo 1-14:1.0: Entity type for entity Extension 6 was not initialized!
[118541.354972] uvcvideo 1-14:1.0: Entity type for entity Camera 1 was not initialized!
[118541.355016] input: Webcam C170: Webcam C170 as /devices/pci0000:00/0000:00:14.0/usb1/1-14/1-14:1.0/input/input51
[118541.355077] usbcore: registered new interface driver uvcvideo
[118541.355078] USB Video Class driver (1.1.1)