Motioneyeos: "Failed to open video device" with supported camera - device id mismatch

[jl2008]

Short description: the camera device id shown in the admin interface does not match the file under /dev/v4l/by-id/and the camera is therefore not recognized. Thanks in advance for looking into it.

The camera (link to the model further below, listed as compatible with MotionEyeOS and used by others) has an id seen below:

[root@meye-0a927c1d ~]# ls -al /dev/v4l/by-id/
total 0
lrwxrwxrwx    1 root     root            12 Dec 31  1969 usb-HD_Camera_Manufacturer_USB_2.0_Camera-video-index0 -> ../../video0

[root@meye-0a927c1d ~]# ls -al /dev/video0
crw-------    1 root     root       81,   0 Dec 31  1969 /dev/video0

However, the software tries a different id:

[1:ml1] [ALR] [VID] v4l2_start: Failed to open video device /dev/v4l/by-id/usb-046d_08b2-video-index0: No such file or directory
[1:ml1] [ERR] [VID] vid_start: V4L2 device failed to open

motionEyeOS Version

I am running motionEyeOS version: 20190119 (installed fresh, not upgraded)

motionEye Version | 0.39.3
Motion Version | 4.1.1

Board Model

I am using the following board/model: Raspberry PI 3B+

Camera

I am using the following type of camera: V4L2

My camera model is: https://www.amazon.com/gp/product/B07C2RL8PB

Network Connection

My motionEyeOS unit is connected to the network via: WiFi.

Peripherals

I am using the following peripherals that I consider relevant to this issue: none.

Log Files

I consider the following log files relevant to this issue:

motion.log
messages.log
boot.log
dmesg.log

[jl2008]

Update: I was able to fix it by forcing the device id to be /dev/video0in thread-1.conf and rebooting. I'll leave this ticket open for a few days or so in case, Calin, you want to have a look at it; I'll close it afterwards in case you don't do it before.

[ccrisan]

@jl2008 this looks like a valid issue so I'm not going to close it. Nevertheless, it's strange how this could happen. The piece of code that comes up with that path is at https://github.com/ccrisan/motioneye/blob/dev/motioneye/v4l2ctl.py#L210.

The only possible explanation I see at this time is the fact that somehow the persistent path has changed since the moment the camera was added. Can you reproduce the issue?

[jl2008]

I'll get a second camera in a few weeks (this one is already installed and doing its job) and will retry. Odd, indeed. I did nothing special: installed MotionEyeOS and then plugged in the camera in the USB port. I think even rebooted when I saw the camera was not found.

I've also just checked what happens if I plug the camera out and then back again, even changing the USB port, just in case it makes a difference. However, that old device name (/dev/v4l/by-id/usb-046d_08b2-video-index0) did not appear back, not even the logs (I grepped all in /var/log for the usb-046d_08b2 substring). Powering off and on the Raspberry Pi doesn't make a difference either, the new name (usb-HD_Camera_Manufacturer_USB_2.0_Camera-video-index0) is the only one that appears.

[jl2008]

An update: I got two more identical cameras. The issue was not present. I used the same version of motioneyeos. I can only shrug, so I'll close the bug.

[MHPbvogt]

Update: I was able to fix it by forcing the device id to be /dev/video0in thread-1.conf and rebooting. I'll leave this ticket open for a few days or so in case, Calin, you want to have a look at it; I'll close it afterwards in case you don't do it before.

Thanks. Fixed it for me. I did change it /data/etc/camera-1.conf
videodevice /dev/video0 had been set to video10 for some reason.