diff --git a/_posts/2024-09-23-problem-with-camera-in-ubuntu.txt b/_posts/2024-09-23-problem-with-camera-in-ubuntu.txt new file mode 100644 index 0000000..9c65bac --- /dev/null +++ b/_posts/2024-09-23-problem-with-camera-in-ubuntu.txt @@ -0,0 +1,222 @@ +--- +categories: tips +date: 2024-09-23 11:30:00 +0200 +excerpt: > + Yesterday Ubuntu saw the webcam, today it doesn't. + I'm looking for the cause of the problem. +lang: en +layout: post +title: Problem with camera in Ubuntu +--- + +I'm writing this post from the perspective of an Ubuntu user. +It is meant to help me solve a camera issue more easily in the future. +I don't want to do the research again, so I decided to publish my notes. +🗒️ + +Hopefully, someone else will also find this content useful. + +---- + +The camera works on my laptop. +The issue occurs on Agnieszka's laptop. +BTW, I recommend her [blog Woman on Rails](https://womanonrails.com). +She doesn't have access to the camera. +🚫 +🎥 + +The simplest solution: **restart your computer**. +🚀 + +Sometimes, hardware-related issues like this +can be resolved simply by rebooting the system, +🔌 +as it forces the OS to reinitialize device drivers. + +TL;DR + +--- + +In Linux, devices are represented as files. +The camera should appear under the path `/dev/video0`. + +```console +$ sudo ls -l /dev/video* +ls: cannot access '/dev/video*': No such file or directory +``` + +On my laptop, the same command looks like this: + +``` +$ sudo ls -l /dev/video* +crw-rw----+ 1 root video 81, 0 /dev/video0 +crw-rw----+ 1 root video 81, 1 /dev/video1 +``` + +Ensure the user is part of the `video` group to access camera devices. +Permissions may be granted directly (the user belongs to the video group) +or indirectly (the user belongs to a group with higher access). +The `groups` command will help you check +which groups your user is directly assigned to. + +Ubuntu has tools to manage video from the command line. +The package is called [v4l-utils](https://linuxtv.org/wiki/index.php/V4l-utils) +and it can be easily installed using apt. +The `v4l-utils` is a collection of command-line tools +that allow you to manage and troubleshoot video devices in Linux. + +I installed this package on both computers. +🔧 + +```console +$ sudo apt install v4l-utils +Reading package lists... Done +Building dependency tree... Done +Reading state information... Done +The following additional packages will be installed: + libv4l2rds0 +The following NEW packages will be installed: + libv4l2rds0 v4l-utils +0 upgraded, 2 newly installed, 0 to remove and 0 not upgraded. +... +``` + +On the problematic laptop, I ran the following command: + +```console +$ sudo v4l2-ctl --list-devices -D +Cannot open device /dev/video0, exiting. +``` + +For comparison, I ran the same command on my laptop: + +```console +$ sudo v4l2-ctl --list-devices -D +USB2.0 HD UVC WebCam: USB2.0 HD (usb-0000:00:14.0-5): + /dev/video0 + /dev/video1 + /dev/media0 + +Driver Info: + Driver name : uvcvideo + Card type : USB2.0 HD UVC WebCam: USB2.0 HD + Bus info : usb-0000:00:14.0-5 + Driver version : 6.8.12 + Capabilities : 0x84a00001 + Video Capture + Metadata Capture + Streaming + Extended Pix Format + Device Capabilities + Device Caps : 0x04200001 + Video Capture + Streaming + Extended Pix Format +Media Driver Info: + Driver name : uvcvideo + Model : USB2.0 HD UVC WebCam: USB2.0 HD + Serial : 0x0001 + Bus info : usb-0000:00:14.0-5 + Media version : 6.8.12 + Hardware revision: 0x00005828 (22568) + Driver version : 6.8.12 +Interface Info: + ID : 0x03000002 + Type : V4L Video +Entity Info: + ID : 0x00000001 (1) + Name : USB2.0 HD UVC WebCam: USB2.0 HD + Function : V4L2 I/O + Flags : default + Pad 0x01000007 : 0: Sink + Link 0x02000010: from remote pad 0x100000a of entity 'Extension 4' (Video Pixel Formatter): Data, Enabled, Immutable +``` + +The system is up to date. +The laptop is not damaged. + +The only solution that comes to mind is a restart. +🔄 +After restarting the laptop, the camera starts working. + +I reused the previous commands and this time the result was different: + +```console +$ sudo ls -l /dev/video* +crw-rw----+ 1 root video 81, 0 /dev/video0 +crw-rw----+ 1 root video 81, 1 /dev/video1 +crw-rw----+ 1 root video 81, 2 /dev/video2 +crw-rw----+ 1 root video 81, 3 /dev/video3 +``` + +```console +$ sudo v4l2-ctl --list-devices -D +Chicony USB2.0 Camera: Chicony (usb-0000:00:14.0-7): + /dev/video0 + /dev/video1 + /dev/video2 + /dev/video3 + /dev/media0 + /dev/media1 + +Driver Info: + Driver name : uvcvideo + Card type : Chicony USB2.0 Camera: Chicony + Bus info : usb-0000:00:14.0-7 + Driver version : 6.2.16 + Capabilities : 0x84a00001 + Video Capture + Metadata Capture + Streaming + Extended Pix Format + Device Capabilities + Device Caps : 0x04200001 + Video Capture + Streaming + Extended Pix Format +Media Driver Info: + Driver name : uvcvideo + Model : Chicony USB2.0 Camera: Chicony + Serial : 01.00.00 + Bus info : usb-0000:00:14.0-7 + Media version : 6.2.16 + Hardware revision: 0x00000002 (2) + Driver version : 6.2.16 +Interface Info: + ID : 0x03000002 + Type : V4L Video +Entity Info: + ID : 0x00000001 (1) + Name : Chicony USB2.0 Camera: Chicony + Function : V4L2 I/O + Flags : default + Pad 0x01000007 : 0: Sink + Link 0x02000013: from remote pad 0x100000a of entity 'Extension 4' (Video Pixel Formatter): Data, Enabled, Immutable +``` + +It looks like a **restart** did the trick. +The cause of the issue is unknown, +but I will monitor if the problem occurs again. + +If the issue persists, +I will check the system logs with `dmesg | grep video` +or `journalctl -xe` might provide more insight. + +So far I don't see anything disturbing: + +```console +$ sudo dmesg | grep video +[ 3.097705] videodev: Linux video capture interface: v2.00 +[ 3.211353] usbcore: registered new interface driver uvcvideo +[ 4.791222] ACPI: video: Video Device [GFX0] (multi-head: yes rom: no post: no) +``` + +However, deeper research allowed me to better understand +the possible causes of the problems. +Common reasons for camera issues in Ubuntu include missing drivers, +conflicts with other software, +or power management settings disabling the camera. + +This guide should help you troubleshoot basic camera issues in Ubuntu. +Hopefully, it saves you some time and frustration! +😄