Hi, On Wed, Jan 5, 2022 at 8:35 PM Robie Basak <1921...@bugs.launchpad.net> wrote: > > > On a MIPI camera through Intel IPU6 platform that its raw V4L2 > loopback interface is preserved for Intel Camera HAL libraries, a relay > daemon + v4l2loopback is used to allow the usage of legacy V4L2 based > apps. > > Why is this camera's raw V4L2 loopback interface being "preserved for > Intel Camera HAL libraries"?
The Intel IPU camera provides only raw image access through kernel V4L2 interface, and one will need the corresponding userspace middleware to manipulate the image/video stream. For IPU6 that is being used on a certain oem platforms, following components are needed: * https://github.com/intel/ipu6-camera-bins: prebuilt proprietary binaries and firmware blobs, * https://github.com/intel/ipu6-camera-hal: camera hardware abstraction layer library, * https://github.com/intel/icamerasrc: gstreamer element plugin. So these components will allow a camera app, with the knowledge of icamerasrc, to retrieve normal image/video streams. For all existing, legacy, v4l2-only camera apps, they will not be able to find /dev/video* as they don't exist at all. And even there are, they will still need the above components to manipulate the image/video for correct presentation. In order to provide best backward compatibility, a v4l2-relayd is used to open hardware camera via gstreamer icamerasrc element and redirect the stream back into kernel v4l2loopback device, then a general, innocent userspace camera app may directly use the video device provided by v4l2loopback. All the components can be found in https://launchpad.net/~oem-solutions-group/+archive/ubuntu/intel-ipu6, and are being proposed for inclusion to Ubuntu archive at. the same time > Is this a requirement for hardware > enablement of this device (and if so, why?), or merely a userspace > software rearrangement? Mostly in the userspace, but we'll need v4l2loopback as a way to redirect processed video/image streams. > What functionality won't work if Ubuntu users on > Focal just use the V4L2 interface without using the "Intel Camera HAL > libraries"? This SRU is only for adding V4L2 Event APIs and a few coverity fixes, so it doesn't really cause functionality changes. However, it's true that v4l2-relayd now installs a /etc/modprobe.d/v4l2-relayd.conf file that specifies module parameters for v4l2loopback. So for Ubuntu users without v4l2-relayd installed, there is no visible difference. > What package provides the "Intel Camera HAL libraries"? Listed above. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1921474 Title: Support client usage notification via V4l2 Event API To manage notifications about this bug go to: https://bugs.launchpad.net/hwe-next/+bug/1921474/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
