Hi team,
I’m having a problem with OBS and the virtual camera function. When I click the “start virtual camera” button in OBS, I get an error titled
“Failed to start virtual camera”
with the text
"Starting the output failed. Please check the log for details.
Note: if you are using the NVENC or AMD encoders, make sure your video drivers are up to date"
It was working Tuesday (March 4), but after I ran garuda-update on Friday morning (March 7) it didn’t work.
Searching returned nothing recent (most references are >12 months old) or reference other commercial operating systems from the usual offenders.
I’ve tried several things (see below), and wondering where I look to next - I’m still relatively new to the “diagnostics” side of working with the community 
Logs:
OBS log: (example at Garuda's PrivateBin) doesn’t show anything obvious (like can’t find FFmpeg or VAAPI); I’m on AMD so figure the “NVENC not supported” is expected behaviour; there’s no AMD encoder error.
When I click the button, the diagnostic lines aren’t really helpful:
14:44:30.086: Failed to start streaming on '/dev/video0' (Invalid argument)
14:44:30.087: Failed to start virtual camera
Journal just replicates the OBS output
journalctl -f
...
Mar 09 14:32:23 machine obs[27750]: error: Failed to start streaming on '/dev/video0' (Invalid argument)
Mar 09 14:32:23 machine obs[27750]: warning: Failed to start virtual camera
...
Things I tried: (no difference)
- I normally use obs-sourcerecord, and thought it might be related to that so I created a new scene collection with just the capture device (no filters etc).
- I normally use obs-studio-stable, and tried replacing with obs-studio.
- Reinstalling v4l2loopback-dkms
- I’m normally use linux-zen, but also tried against linux-lts
- More garuda-update
Other info
>> v4l2-ctl --list-devices
Virtual Cam (platform:v4l2loopback-000):
/dev/video0
[other devices]
>>cat /etc/modprobe.d/v4l2-obs-studio.conf
options v4l2loopback card_label="Virtual Cam" video_nr=0 exclusive_caps=1
>>ffmpeg -hwaccels
ffmpeg version n7.1 Copyright (c) 2000-2024 the FFmpeg developers
built with gcc 14.2.1 (GCC) 20240910
configuration: --prefix=/usr --disable-debug --disable-static --disable-stripping --enable-amf --enable-avisynth --enable-cuda-llvm --enable-lto --enable-fontconfig --enable-frei0r --enable-gmp --enable-gnutls --enable-gpl --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libbs2b --enable-libdav1d --enable-libdrm --enable-libdvdnav --enable-libdvdread --enable-libfreetype --enable-libfribidi --enable-libglslang --enable-libgsm --enable-libharfbuzz --enable-libiec61883 --enable-libjack --enable-libjxl --enable-libmodplug --enable-libmp3lame --enable-libopencore_amrnb --enable-libopencore_amrwb --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libplacebo --enable-libpulse --enable-librav1e --enable-librsvg --enable-librubberband --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libsrt --enable-libssh --enable-libsvtav1 --enable-libtheora --enable-libv4l2 --enable-libvidstab --enable-libvmaf --enable-libvorbis --enable-libvpl --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxcb --enable-libxml2 --enable-libxvid --enable-libzimg --enable-libzmq --enable-nvdec --enable-nvenc --enable-opencl --enable-opengl --enable-shared --enable-vapoursynth --enable-version3 --enable-vulkan
libavutil 59. 39.100 / 59. 39.100
libavcodec 61. 19.100 / 61. 19.100
libavformat 61. 7.100 / 61. 7.100
libavdevice 61. 3.100 / 61. 3.100
libavfilter 10. 4.100 / 10. 4.100
libswscale 8. 3.100 / 8. 3.100
libswresample 5. 3.100 / 5. 3.100
libpostproc 58. 3.100 / 58. 3.100
Hardware acceleration methods:
vdpau
cuda
vaapi
qsv
drm
opencl
vulkan
vainfo
Trying display: wayland
vainfo: VA-API version: 1.22 (libva 2.22.0)
vainfo: Driver version: Mesa Gallium driver 24.3.4-arch1.1 for AMD Radeon Graphics (radeonsi, renoir, LLVM 19.1.7, DRM 3.61, 6.13.5-zen1-1-zen)
vainfo: Supported profile and entrypoints
VAProfileMPEG2Simple : VAEntrypointVLD
VAProfileMPEG2Main : VAEntrypointVLD
VAProfileVC1Simple : VAEntrypointVLD
VAProfileVC1Main : VAEntrypointVLD
VAProfileVC1Advanced : VAEntrypointVLD
VAProfileH264ConstrainedBaseline: VAEntrypointVLD
VAProfileH264ConstrainedBaseline: VAEntrypointEncSlice
VAProfileH264Main : VAEntrypointVLD
VAProfileH264Main : VAEntrypointEncSlice
VAProfileH264High : VAEntrypointVLD
VAProfileH264High : VAEntrypointEncSlice
VAProfileHEVCMain : VAEntrypointVLD
VAProfileHEVCMain : VAEntrypointEncSlice
VAProfileHEVCMain10 : VAEntrypointVLD
VAProfileHEVCMain10 : VAEntrypointEncSlice
VAProfileJPEGBaseline : VAEntrypointVLD
VAProfileVP9Profile0 : VAEntrypointVLD
VAProfileVP9Profile2 : VAEntrypointVLD
VAProfileNone : VAEntrypointVideoProc
garuda-inxi output:
System:
Kernel: 6.13.5-zen1-1-zen arch: x86_64 bits: 64 compiler: gcc v: 14.2.1
clocksource: hpet avail: acpi_pm
parameters: BOOT_IMAGE=/@/boot/vmlinuz-linux-zen
root=UUID=b6b512c6-dcf8-4c8f-a68e-7657304a58ac rw rootflags=subvol=@
quiet resume=UUID=2829d8f2-ea1e-4f9d-bfb8-627f70c79865 loglevel=3 ibt=off
Desktop: KDE Plasma v: 6.3.2 tk: Qt v: N/A info: frameworks v: 6.11.0
wm: kwin_wayland vt: 1 dm: SDDM Distro: Garuda base: Arch Linux
Machine:
Type: Laptop System: Micro-Star product: Delta 15 A5EFK v: REV:1.0
serial: <superuser required> Chassis: type: 10 serial: <superuser required>
Mobo: Micro-Star model: MS-15CK v: REV:1.0 serial: <superuser required>
part-nu: 15CK.1 uuid: <superuser required> UEFI: American Megatrends LLC.
v: E15CKAMS.10C date: 08/01/2023
Battery:
ID-1: BAT1 charge: 66.2 Wh (95.1%) condition: 69.6/80.3 Wh (86.7%)
volts: 16.6 min: 15.2 model: MSI Corp. MS-15CK type: Li-ion serial: N/A
status: not charging
CPU:
Info: model: AMD Ryzen 9 5900HX with Radeon Graphics bits: 64 type: MT MCP
arch: Zen 3 gen: 3 level: v3 note: check built: 2021-22
process: TSMC n7 (7nm) family: 0x19 (25) model-id: 0x50 (80) stepping: 0
microcode: 0xA500011
Topology: cpus: 1x dies: 1 clusters: 1 cores: 8 threads: 16 tpc: 2
smt: enabled cache: L1: 512 KiB desc: d-8x32 KiB; i-8x32 KiB L2: 4 MiB
desc: 8x512 KiB L3: 16 MiB desc: 1x16 MiB
Speed (MHz): avg: 2587 min/max: 400/4680 boost: enabled scaling:
driver: amd-pstate-epp governor: powersave cores: 1: 2587 2: 2587 3: 2587
4: 2587 5: 2587 6: 2587 7: 2587 8: 2587 9: 2587 10: 2587 11: 2587 12: 2587
13: 2587 14: 2587 15: 2587 16: 2587 bogomips: 105409
Flags: avx avx2 ht lm nx pae sse sse2 sse3 sse4_1 sse4_2 sse4a ssse3 svm
Vulnerabilities: <filter>
Graphics:
Device-1: Advanced Micro Devices [AMD/ATI] Navi 22 [Radeon RX 6700/6700
XT/6750 XT / 6800M/6850M XT] vendor: Micro-Star MSI driver: amdgpu
v: kernel arch: RDNA-2 code: Navi-2x process: TSMC n7 (7nm) built: 2020-22
pcie: gen: 4 speed: 16 GT/s lanes: 16 ports: active: DP-1
empty: HDMI-A-1,Writeback-1 bus-ID: 03:00.0 chip-ID: 1002:73df
class-ID: 0380
Device-2: Advanced Micro Devices [AMD/ATI] Cezanne [Radeon Vega Series /
Radeon Mobile Series] vendor: Micro-Star MSI driver: amdgpu v: kernel
arch: GCN-5 code: Vega process: GF 14nm built: 2017-20 pcie: gen: 3
speed: 8 GT/s lanes: 16 ports: active: eDP-1 empty: none bus-ID: 07:00.0
chip-ID: 1002:1638 class-ID: 0300 temp: 56.0 C
Device-3: Bison HD Webcam driver: uvcvideo type: USB rev: 2.0
speed: 480 Mb/s lanes: 1 mode: 2.0 bus-ID: 1-3:2 chip-ID: 5986:211c
class-ID: 0e02
Device-4: Magic Control J5-USB Device driver: snd-usb-audio,uvcvideo
type: USB rev: 2.1 speed: 480 Mb/s lanes: 1 mode: 2.0 bus-ID: 3-1.1:4
chip-ID: 0711:0a05 class-ID: 0102 serial: <filter>
Display: wayland server: X.org v: 1.21.1.16 with: Xwayland v: 24.1.6
compositor: kwin_wayland driver: X: loaded: amdgpu
unloaded: modesetting,radeon alternate: fbdev,vesa dri: radeonsi
gpu: amdgpu d-rect: 5360x2520 display-ID: 0
Monitor-1: DP-1 pos: primary,top-left model: Samsung C34H89x
serial: <filter> built: 2020 res: mode: 3440x1440 hz: 100 scale: 100% (1)
dpi: 110 gamma: 1.2 size: 797x333mm (31.38x13.11") diag: 864mm (34")
modes: max: 3440x1440 min: 720x400
Monitor-2: eDP-1 pos: bottom-r model: Sharp LQ156M1JW03 built: 2021 res:
mode: 1920x1080 hz: 240 scale: 100% (1) dpi: 142 gamma: 1.2
size: 344x194mm (13.54x7.64") diag: 395mm (15.5") ratio: 16:9 modes:
max: 1920x1080 min: 640x480
API: EGL v: 1.5 hw: drv: amd radeonsi platforms: device: 0 drv: radeonsi
device: 1 drv: radeonsi device: 2 drv: swrast gbm: drv: kms_swrast
surfaceless: drv: radeonsi wayland: drv: radeonsi x11: drv: radeonsi
API: OpenGL v: 4.6 compat-v: 4.5 vendor: amd mesa v: 24.3.4-arch1.1
glx-v: 1.4 direct-render: yes renderer: AMD Radeon Graphics (radeonsi
renoir LLVM 19.1.7 DRM 3.61 6.13.5-zen1-1-zen) device-ID: 1002:1638
memory: 500 MiB unified: no display-ID: :1.0
API: Vulkan v: 1.4.304 layers: 12 device: 0 type: integrated-gpu name: AMD
Radeon Graphics (RADV RENOIR) driver: N/A device-ID: 1002:1638
surfaces: xcb,xlib,wayland device: 1 type: discrete-gpu name: AMD Radeon
RX 6700M (RADV NAVI22) driver: N/A device-ID: 1002:73df
surfaces: xcb,xlib,wayland device: 2 type: cpu name: llvmpipe (LLVM
19.1.7 256 bits) driver: N/A device-ID: 10005:0000
surfaces: xcb,xlib,wayland
Info: Tools: api: clinfo, eglinfo, glxinfo, vulkaninfo
de: kscreen-console,kscreen-doctor gpu: amd-smi, corectrl, radeontop
wl: wayland-info x11: xdpyinfo, xprop, xrandr
Audio:
Device-1: Advanced Micro Devices [AMD/ATI] Navi 21/23 HDMI/DP Audio
driver: snd_hda_intel v: kernel pcie: gen: 4 speed: 16 GT/s lanes: 16
bus-ID: 03:00.1 chip-ID: 1002:ab28 class-ID: 0403
Device-2: Advanced Micro Devices [AMD/ATI] Renoir Radeon High Definition
Audio driver: snd_hda_intel v: kernel pcie: gen: 3 speed: 8 GT/s lanes: 16
bus-ID: 07:00.1 chip-ID: 1002:1637 class-ID: 0403
Device-3: Advanced Micro Devices [AMD] ACP/ACP3X/ACP6x Audio Coprocessor
vendor: Micro-Star MSI driver: snd_rn_pci_acp3x v: kernel
alternate: snd_pci_acp3x, snd_pci_acp5x, snd_pci_acp6x, snd_acp_pci,
snd_rpl_pci_acp6x, snd_pci_ps, snd_sof_amd_renoir, snd_sof_amd_rembrandt,
snd_sof_amd_vangogh, snd_sof_amd_acp63, snd_sof_amd_acp70 pcie: gen: 3
speed: 8 GT/s lanes: 16 bus-ID: 07:00.5 chip-ID: 1022:15e2 class-ID: 0480
Device-4: Advanced Micro Devices [AMD] Family 17h/19h/1ah HD Audio
vendor: Micro-Star MSI driver: snd_hda_intel v: kernel pcie: gen: 3
speed: 8 GT/s lanes: 16 bus-ID: 07:00.6 chip-ID: 1022:15e3 class-ID: 0403
Device-5: Magic Control J5-USB Device driver: snd-usb-audio,uvcvideo
type: USB rev: 2.1 speed: 480 Mb/s lanes: 1 mode: 2.0 bus-ID: 3-1.1:4
chip-ID: 0711:0a05 class-ID: 0102 serial: <filter>
Device-6: C-Media CM106 Like Sound Device
driver: hid-generic,snd-usb-audio,usbhid type: USB rev: 1.1 speed: 12 Mb/s
lanes: 1 mode: 1.1 bus-ID: 3-1.4.2:12 chip-ID: 0d8c:0102 class-ID: 0300
API: ALSA v: k6.13.5-zen1-1-zen status: kernel-api with: aoss
type: oss-emulator tools: N/A
Server-1: sndiod v: N/A status: off tools: aucat,midicat,sndioctl
Server-2: PipeWire v: 1.2.7 status: active with: 1: pipewire-pulse
status: active 2: wireplumber status: active 3: pipewire-alsa type: plugin
4: pw-jack type: plugin tools: pactl,pw-cat,pw-cli,wpctl
Network:
Device-1: Intel Wi-Fi 6E AX210/AX1675 2x2 [Typhoon Peak] driver: iwlwifi
v: kernel pcie: gen: 2 speed: 5 GT/s lanes: 1 bus-ID: 04:00.0
chip-ID: 8086:2725 class-ID: 0280
IF: wlp4s0 state: up mac: <filter>
Device-2: ASIX AX88772B driver: asix type: USB rev: 2.0 speed: 480 Mb/s
lanes: 1 mode: 2.0 bus-ID: 3-1.4.1:11 chip-ID: 0b95:772b class-ID: ff00
serial: <filter>
IF: enp7s0f4u1u4u1 state: up speed: 100 Mbps duplex: full mac: <filter>
Info: services: NetworkManager, smbd, sshd, systemd-timesyncd,
wpa_supplicant
Bluetooth:
Device-1: Intel AX210 Bluetooth driver: btusb v: 0.8 type: USB rev: 2.0
speed: 12 Mb/s lanes: 1 mode: 1.1 bus-ID: 3-3:5 chip-ID: 8087:0032
class-ID: e001
Report: btmgmt ID: hci0 rfk-id: 0 state: up address: <filter> bt-v: 5.3
lmp-v: 12 status: discoverable: no pairing: no class-ID: 6c010c
Drives:
Local Storage: total: 2.75 TiB used: 1.73 TiB (62.7%)
SMART Message: Unable to run smartctl. Root privileges required.
ID-1: /dev/nvme0n1 maj-min: 259:0 vendor: Micron model: 2210 MTFDHBA1T0QFD
size: 953.87 GiB block-size: physical: 512 B logical: 512 B speed: 31.6 Gb/s
lanes: 4 tech: SSD serial: <filter> fw-rev: P6MA001 temp: 51.9 C
scheme: GPT
ID-2: /dev/nvme1n1 maj-min: 259:7 vendor: Western Digital
model: WD Blue SN570 2TB size: 1.82 TiB block-size: physical: 512 B
logical: 512 B speed: 31.6 Gb/s lanes: 4 tech: SSD serial: <filter>
fw-rev: 234140WD temp: 45.9 C scheme: GPT
Partition:
ID-1: / raw-size: 1.79 TiB size: 1.79 TiB (100.00%) used: 1.01 TiB (56.7%)
fs: btrfs dev: /dev/nvme1n1p2 maj-min: 259:9
ID-2: /boot/efi raw-size: 300 MiB size: 299.4 MiB (99.80%)
used: 11.2 MiB (3.7%) fs: vfat dev: /dev/nvme1n1p1 maj-min: 259:8
ID-3: /home raw-size: 1.79 TiB size: 1.79 TiB (100.00%)
used: 1.01 TiB (56.7%) fs: btrfs dev: /dev/nvme1n1p2 maj-min: 259:9
ID-4: /var/log raw-size: 1.79 TiB size: 1.79 TiB (100.00%)
used: 1.01 TiB (56.7%) fs: btrfs dev: /dev/nvme1n1p2 maj-min: 259:9
ID-5: /var/tmp raw-size: 1.79 TiB size: 1.79 TiB (100.00%)
used: 1.01 TiB (56.7%) fs: btrfs dev: /dev/nvme1n1p2 maj-min: 259:9
Swap:
Kernel: swappiness: 133 (default 60) cache-pressure: 100 (default) zswap: no
ID-1: swap-1 type: zram size: 30.73 GiB used: 0 KiB (0.0%) priority: 100
comp: zstd avail: lzo-rle,lzo,lz4,lz4hc,deflate,842 max-streams: 16
dev: /dev/zram0
ID-2: swap-2 type: partition size: 33.81 GiB used: 0 KiB (0.0%)
priority: -2 dev: /dev/nvme1n1p3 maj-min: 259:10
Sensors:
System Temperatures: cpu: 66.1 C mobo: N/A
Fan Speeds (rpm): N/A
GPU: device: amdgpu temp: 51.0 C mem: 48.0 C fan: 0 watts: 9.00
device: amdgpu temp: 57.0 C
Info:
Memory: total: 32 GiB note: est. available: 30.73 GiB
used: 13.95 GiB (45.4%)
Processes: 468 Power: uptime: 12m states: freeze,mem,disk suspend: s2idle
wakeups: 0 hibernate: platform avail: shutdown, reboot, suspend, test_resume
image: 12.27 GiB services: org_kde_powerdevil, power-profiles-daemon,
upowerd Init: systemd v: 257 default: graphical tool: systemctl
Packages: 2567 pm: pacman pkgs: 2547 libs: 594 tools: octopi,paru,yay
pm: flatpak pkgs: 20 Compilers: clang: 19.1.7 gcc: 14.2.1 Shell: garuda-inxi
default: fish v: 4.0.0 running-in: kate inxi: 3.3.37
Garuda (2.7.2-1):
System install date: 2024-01-23
Last full system update: 2025-03-09
Is partially upgraded: No
Relevant software: snapper NetworkManager dracut
Windows dual boot: Probably (Run as root to verify)
Failed units:
