[Bug 2131647] Re: pipewire failed to work with v4l2loopback devices

[Julian Andres Klode]

Hello Dirk, or anyone else affected,

Accepted pipewire into noble-proposed. The package will build now and be
available at
https://launchpad.net/ubuntu/+source/pipewire/1.0.5-1ubuntu3.2 in a few
hours, and then in the -proposed repository.

Please help us by testing this new package.  See
https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how
to enable and use -proposed.  Your feedback will aid us getting this
update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug,
mentioning the version of the package you tested, what testing has been
performed on the package and change the tag from verification-needed-
noble to verification-done-noble. If it does not fix the bug for you,
please add a comment stating that, and change the tag to verification-
failed-noble. In either case, without details of your testing we will
not be able to proceed.

Further information regarding the verification process can be found at
https://wiki.ubuntu.com/QATeam/PerformingSRUVerification .  Thank you in
advance for helping!

N.B. The updated package will be released to -updates after the bug(s)
fixed by this package have been verified and the package has been in
-proposed for a minimum of 7 days.

** Changed in: pipewire (Ubuntu Noble)
       Status: Confirmed => Fix Committed

** Tags added: verification-needed verification-needed-noble

-- 
You received this bug notification because you are a member of Ubuntu
Sponsors, which is subscribed to the bug report.
https://bugs.launchpad.net/bugs/2131647

Title:
  pipewire failed to work with v4l2loopback devices

Status in pipewire package in Ubuntu:
  Fix Released
Status in pipewire source package in Noble:
  Fix Committed

Bug description:
  [Impact]
  Using pipewire with video device created by v4l2loopback will get following error log

  $ gst-launch-1.0 pipewiresrc ! videoconvert ! autovideosink
  Setting pipeline to PAUSED ...
  ERROR: from element /GstPipeline:pipeline0/GstPipeWireSrc:pipewiresrc0: stream error: can't negotiate buffers on port
  Additional debug info:
  ../src/gst/gstpipewiresrc.c(692): on_state_changed (): /GstPipeline:pipeline0/GstPipeWireSrc:pipewiresrc0
  ERROR: pipeline doesn't want to preroll.
  ERROR: from element /GstPipeline:pipeline0/GstPipeWireSrc:pipewiresrc0: Internal data stream error.
  Additional debug info:
  ../libs/gst/base/gstbasesrc.c(3177): gst_base_src_loop (): /GstPipeline:pipeline0/GstPipeWireSrc:pipewiresrc0:
  streaming stopped, reason not-negotiated (-4)
  Failed to set pipeline to PAUSED.
  ERROR: pipeline doesn't want to preroll.
  Setting pipeline to NULL ...
  Freeing pipeline ...

  [ Test Plan ]
  Need to test two kind of scenarios
   1. video device of USB camera
     - play video with command "gst-launch-1.0 pipewiresrc ! videoconvert ! autovideosink"
   2. virtual video device created by v4l2loopback
     - insert v4l2loopback kernel module with command "sudo modprobe v4l2loopback card_label="v4l2 Visual Webcam" exclusive_caps=1"
     - get video device with command "ls /sys/devcies/virtual | grep video"
     - generate video source to device get in previous step with command "gst-launch-1.0 videotestsrc ! video/x-raw,format=YUY2 ! identity drop-allocation=true ! v4l2sink device=/dev/{VIDEO_DEVICE}"
     - reload pipewire with command "systemctl --user restart pipewire.service"
     - get video source number with "wpctl status | grep "v4l2 Visual Webcam (V4L2)"
     - play video with command "gst-launch-1.0 pipewiresrc path={VIDEO_SOURCE_NUMBER} ! videoconvert ! autovideosink"

  [ Where problems could occur ]
  This SRU add V4L2 video fallback method mmap, the origin method USERPTR should still works without problem. The risk should be low. But modify V4L2 video handling may have chance cause video unable to play.

  [ Other Info ]
  related upstream patches
  https://gitlab.freedesktop.org/pipewire/pipewire/-/commit/b2dd733520667f90896cc0eb10f3614d4f7f961a
  https://gitlab.freedesktop.org/pipewire/pipewire/-/commit/877c262e7877defff9462d4ece1c44d87bbc3caf
  https://gitlab.freedesktop.org/pipewire/pipewire/-/commit/37eef2cf2370c9dee47820855b8d60bfc52da41a
  https://gitlab.freedesktop.org/pipewire/pipewire/-/commit/b9df297e2a2704934bd7d9e04f754eb6ea161576

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/pipewire/+bug/2131647/+subscriptions