Hi On 2022. december 26., hétfő 10:52, Laurent Pinchart wrote: > Hi Kieran, > > Thank you for the patch. > > On Fri, Dec 23, 2022 at 11:17:35PM +0000, Kieran Bingham wrote: > > > Provide a streaming attribute to allow userspace to interogate if a device > > is actively streaming or not. > > > > This will allow desktop notifications to report if a camera or device > > is active on the system, rather than just 'open' which can occur when > > configuring the device. > > > > Bug: https://gitlab.freedesktop.org/pipewire/pipewire/-/issues/2669 > > Signed-off-by: Kieran Bingham kieran.bingham@xxxxxxxxxxxxxxxx > > --- > > > > This is a quick POC to see if such a facility makes sense. > > I'm weary that not all video devices may have the queues registered on > > the struct video_device, but this seems like an effective way to be able > > to determine if a device is actively streaming on a system. > > > I can imagine multiple problems, from race conditions to permissions and > privacy. In order to comment on the fitness of this solution to address > the problem you're trying to solve, could you describe the actual > problem ? The issue is explained in the following thread: https://gitlab.freedesktop.org/pipewire/pipewire/-/issues/2669#note_1697388 In short, the user wants to show a "camera-in-use" indicator when the laptop camera is used. The script that the user previously had only checked if /dev/video0 was open in any process, if it was, the indicator was shown. However, libcamera - at least at the moment - keeps the file descriptor open as long as the Camera object exists, which pipewire keeps alive for the entire lifetime of the device, therefore the "camera-in-use" indicator is always shown. > [...] Regards, Barnabás Pőcze
