Hardware specifics

IPU 7 webcam

This follows along the Guide on the ArchWiki for a specific laptop model.

Before starting, you’ll want to install libcamera-tools to check whether the situation has improved in the meantime:

yay -S libcamera-tools

You can use:

cam -l
qcam

for testing things.

If this does not show something useful (see the Guide on the ArchWiki, install DKMS and kernel headers so DKMS can be used:

yay -S dkms linux-lts-headers linux-headers

Then, install Intel Vision Drivers (DKMS) from AUR:

yay -S intel-vision-drivers-dkms-git

Finally, create /etc/modules-load.d/intel_cvs.conf with content:

intel_cvs

and run, just to be safe:

mkinitcpio -P

and reboot. The commands from above should work now, you should see a camera picture with non-ideal quality.

Now, install the tooling necessary to use the camera in actual applications.

yay -S gst-plugin-libcamera pipewire-libcamera

Restart user-level pipewire service afterwards:

systemctl restart --user pipewire

In Firefox, set media.webrtc.camera.allow-pipewire in about:config to True. In Chromium, set enable-webrtc-pipewire-camerainchrome://flags/`. Both browsers need a restart for things to work.

Sadly, I am currently still getting segmentation faults of Pipewire and also when trying:

gst-launch-1.0 libcamerasrc ! video/x-raw,format=RGBA,width=1920,height=1080,framerate=30/1 ! videoconvert ! ximagesink

but for example qcam works. However, trying with another resolution:

gst-launch-1.0 libcamerasrc ! video/x-raw,format=RGBA,width=1920,height=1200,framerate=30/1 ! videoconvert ! ximagesink

works fine. It still breaks in Firefox etc. as likely they use a different resolution by default.

You will also want to set up v4l2-relayd as follows:

yay -S v4l2loopback-dkms v4l2-relayd

Now, load the module:

sudo modprobe v4l2loopback

and create a config for v4l2-relayd and start it. For that, first create /etc/v4l2-relayd.d/frontcam.conf with content:

# GStreamer source element name:
VIDEOSRC="libcamerasrc"
#SPLASHSRC="filesrc location=/.../splash.png ! pngdec ! imagefreeze num-buffers=4 ! videoscale ! videoconvert"

# Output format, width, height, and frame rate:
FORMAT=NV12
WIDTH=1920
HEIGHT=1200
FRAMERATE=30/1

# Virtual video device name:
CARD_LABEL="Dummy video device \(0x0000\)"

# Extra options to pass to v4l2-relayd:
EXTRA_OPTS=-d

Then, let it generate a systemd service froim that and start things:

systemctl daemon-reload
systemctl start v4l2-relayd

You can now check the status via:

systemctl status v4l2-relayd@frontcam.service

In principle, the camera should now also be accessible as a V4L2 device, but it still fails for me.

However, the camera is accessible via OBS on my system. Hence, the service above was not enabled permanenty. The following kind of works:

• Set up OBS, add a pipewire recording device, and select the camera, use resolution 1920x1200 and match it to full recording screen.
• Start virtual camera from OBS. Note that you must systemctl stop v4l2-relayd@frontcam.service first.

Sadly, Firefox crashes trying to access that, even though:

mpv av://v4l2:/dev/video32

works fine.

Hybrid graphics: Initialization order

In case you are using hybrid graphics, it might happen that the initialization order of both GPUs is not guaranteed, which can lead to issues down the line (e.g. outputs enumerated and hence named differently between restarts, EDID patches not applied etc.). An order can be enforced for example by creating the file /etc/modprobe.d/nvidia-before-intel.conf with content:

softdep i915 pre: nvidia_drm nvidia_modeset nvidia_uvm nvidia

and running:

mkinitcpio -P

afterwards.

Applying EDID patches

In some cases, you may need to patch the EDID of your monitor, e.g. to force support for different refresh rates with Wayland (which does not support custom modelines on its own, unlike X11). Note that an alternative to the approach described below are custom modelines which can be created via kscreen-doctor in KDE/Plasma environments.

To create a custom EDID, you can for example use CRU via Wine. You might also have success with edid-generator.

To apply a custom EDID, you can place a patched EDID e.g. in /lib/firmware/edid/Samsung-Syncmaster-patched.edid and then edit /etc/mkinitcpio.conf to contain:

FILES=( /lib/firmware/edid/Samsung-Syncmaster-patched.edid )

Then, add:

drm.edid_firmware=HDMI-A-1:edid/Samsung-Syncmaster-patched.edid

to the kernel command line, and run:

mkinitcpio -P

afterwards and reboot the system.