[libcamera-devel] [PATCH] cam: Add --monitor option
Niklas Söderlund
niklas.soderlund at ragnatech.se
Mon Jul 13 20:21:54 CEST 2020
Hi Umang,
On 2020-07-13 15:53:15 +0000, Umang Jain wrote:
> Hi Niklas,
>
> Thanks for the review.
>
> On 7/13/20 7:35 PM, Niklas Söderlund wrote:
> > Hi Umang,
> >
> > Thanks for your work.
> >
> > On 2020-07-13 12:11:28 +0000, Umang Jain wrote:
> > > Add --monitor to monitor new hotplug and unplug camera events from
> > > the CameraManager.
> > >
> > > Signed-off-by: Umang Jain <email at uajain.com>
> > First off, for this patch.
> >
> > Reviewed-by: Niklas Söderlund <niklas.soderlund at ragnatech.se>
> >
> > When testing this patch to discover how far hotplug support have come I
> > noticed some issues. I'm not aware if you know about them or not so I
> > will describe them here.
> >
> > 1. Error message printed from cam
> >
> > When I run cam --monitor and physically unplug and then replug a USB
> > UVC camera I get the following ERROR:
> >
> > $ cam --monitor
> >
> > * unplug camera *
> > Camera Removed: Logitech Webcam C930e
> > [465:45:06.515424906] [593092] ERROR V4L2 v4l2_videodevice.cpp:1117 /dev/video0[cap]: Unable to request 0 buffers: No such device
> >
> > * plug camera *
> > Camera Added: Logitech Webcam C930e
> >
> > Would it be possible to not print the error when unplugging? I
> > understand the IOCTL can never succeed as the vidoe device is gone
> > but maybe we could avoid logging the error.
> hmm, I am not sure if we can suppress logging that error without much
> invasive changes.
> On looking around, I noticed there couple of places where
> V4L2VideoDevice::requestBuffers()
> is called, with request buffer count = 0. This particular one, is being
> called from releaseBuffers.
> >
> > 2. Qcam hits a delayed assert with hot-plug
> >
> > Once more the USB UVC camera is used.
> >
> > $ qcam
> > [465:59:29.856991110] [599647] INFO IPAManager ipa_manager.cpp:136 libcamera is not installed. Adding '/home/neg/work/libcamera/libcamera/build/normal/src/ipa' to the IPA search path
> > [465:59:29.858010955] [599647] INFO Camera camera_manager.cpp:283 libcamera v0.0.0+1602-7a13375c
> > [465:59:29.870436670] [599649] INFO IPAProxy ipa_proxy.cpp:122 libcamera is not installed. Loading IPA configuration from '/home/neg/work/libcamera/libcamera/src/ipa/vimc/data'
> > [465:59:36.255358189] [599647] INFO Camera camera.cpp:770 configuring streams: (0) 1920x1080-MJPEG
> > Using software format conversion from MJPEG
> > seq: 000000 bytesused: 151768 timestamp: 1677576692011000 fps: 0.00
> > seq: 000001 bytesused: 157570 timestamp: 1677576715997000 fps: 41.69
> > seq: 000002 bytesused: 158088 timestamp: 1677576751996000 fps: 27.78
> > seq: 000003 bytesused: 158089 timestamp: 1677576783994000 fps: 31.25
> > ....
> > seq: 000080 bytesused: 167393 timestamp: 1677579347940000 fps: 31.25
> > seq: 000081 bytesused: 167030 timestamp: 1677579383939000 fps: 27.78
> > seq: 000082 bytesused: 167221 timestamp: 1677579415938000 fps: 31.25
> > seq: 000083 bytesused: 166575 timestamp: 1677579447937000 fps: 31.25
> > seq: 000084 bytesused: 165611 timestamp: 1677579483936000 fps: 27.78
> > seq: 000085 bytesused: 166295 timestamp: 1677579515936000 fps: 31.25
> >
> > * unplug camera *
> > Removing camera: Logitech Webcam C930e
> > Failed to stop capture
> >
> > * wait a while *
> >
> > * close qcam *
> > [465:59:47.587993893] [599647] ERROR V4L2 v4l2_videodevice.cpp:1117 /dev/video0[cap]: Unable to request 0 buffers: No such device
> > [465:59:47.588042533] [599649] FATAL default event_dispatcher_poll.cpp:258 assertion "iter != notifiers_.end()" failed
> > Backtrace:
> > /home/neg/work/libcamera/libcamera/build/normal/src/qcam/../libcamera/libcamera.so(_ZN9libcamera19EventDispatcherPoll16processNotifiersERKSt6vectorI6pollfdSaIS2_EE+0x150) [0x7ffb28d9ae52]
> > /home/neg/work/libcamera/libcamera/build/normal/src/qcam/../libcamera/libcamera.so(_ZN9libcamera19EventDispatcherPoll13processEventsEv+0x2b9) [0x7ffb28d9a75f]
> > /home/neg/work/libcamera/libcamera/build/normal/src/qcam/../libcamera/libcamera.so(_ZN9libcamera6Thread4execEv+0x8a) [0x7ffb28de4396]
> > /home/neg/work/libcamera/libcamera/build/normal/src/qcam/../libcamera/libcamera.so(_ZN9libcamera13CameraManager7Private3runEv+0x104) [0x7ffb28d4c0d4]
> > /home/neg/work/libcamera/libcamera/build/normal/src/qcam/../libcamera/libcamera.so(_ZN9libcamera6Thread11startThreadEv+0xe5) [0x7ffb28de42ff]
> > /home/neg/work/libcamera/libcamera/build/normal/src/qcam/../libcamera/libcamera.so(_ZSt13__invoke_implIvMN9libcamera6ThreadEFvvEPS1_JEET_St21__invoke_memfun_derefOT0_OT1_DpOT2_+0x67) [0x7ffb28de8c2b]
> > /home/neg/work/libcamera/libcamera/build/normal/src/qcam/../libcamera/libcamera.so(_ZSt8__invokeIMN9libcamera6ThreadEFvvEJPS1_EENSt15__invoke_resultIT_JDpT0_EE4typeEOS6_DpOS7_+0x37) [0x7ffb28de8b6d]
> > /home/neg/work/libcamera/libcamera/build/normal/src/qcam/../libcamera/libcamera.so(_ZNSt6thread8_InvokerISt5tupleIJMN9libcamera6ThreadEFvvEPS3_EEE9_M_invokeIJLm0ELm1EEEEvSt12_Index_tupleIJXspT_EEE+0x43) [0x7ffb28de8add]
> > /home/neg/work/libcamera/libcamera/build/normal/src/qcam/../libcamera/libcamera.so(_ZNSt6thread8_InvokerISt5tupleIJMN9libcamera6ThreadEFvvEPS3_EEEclEv+0x18) [0x7ffb28de8a96]
> > /home/neg/work/libcamera/libcamera/build/normal/src/qcam/../libcamera/libcamera.so(_ZNSt6thread11_State_implINS_8_InvokerISt5tupleIJMN9libcamera6ThreadEFvvEPS4_EEEEE6_M_runEv+0x1c) [0x7ffb28de8a7a]
> > /usr/lib/libstdc++.so.6(+0xcfb74) [0x7ffb27582b74]
> > /usr/lib/libpthread.so.0(+0x9422) [0x7ffb26f7d422]
> > /usr/lib/libc.so.6(clone+0x43) [0x7ffb273cfbf3]
> Yes, I am aware of QCam issue. I suppose you only had one camera(i.e. UVC)
> on the system and trying to plug/unplug that?
> Or did you have multiple ?
I have two cameras in my system for this test a uvc and vimc pipeline.
$ cam -l
Available cameras:
1: Logitech Webcam C930e
2: VIMC Sensor B
If I remove the vimc kernel driver and thus only have one (uvc) camera
and run the test described above I get the same result.
>
> QCam still has some corners cases with one camera attached to the system
> when I looked at it last time.
> >
> > > ---
> > > src/cam/main.cpp | 24 ++++++++++++++++++++++++
> > > src/cam/main.h | 1 +
> > > 2 files changed, 25 insertions(+)
> > >
> > > diff --git a/src/cam/main.cpp b/src/cam/main.cpp
> > > index 2512fe9..3488315 100644
> > > --- a/src/cam/main.cpp
> > > +++ b/src/cam/main.cpp
> > > @@ -36,6 +36,8 @@ public:
> > > void quit();
> > > private:
> > > + void cameraAdded(std::shared_ptr<Camera> cam);
> > > + void cameraRemoved(std::shared_ptr<Camera> cam);
> > > int parseOptions(int argc, char *argv[]);
> > > int prepareConfig();
> > > int listControls();
> > > @@ -115,6 +117,10 @@ int CamApp::init(int argc, char **argv)
> > > ret = prepareConfig();
> > > if (ret)
> > > return ret;
> > > + } else if (options_.isSet(OptMonitor)) {
> > > + cm_->cameraAdded.connect(this, &CamApp::cameraAdded);
> > > + cm_->cameraRemoved.connect(this, &CamApp::cameraRemoved);
> > > + std::cout << "Monitoring new hotplug and unplug events..." << std::endl;
> > > }
> > > loop_ = new EventLoop(cm_->eventDispatcher());
> > > @@ -179,6 +185,8 @@ int CamApp::parseOptions(int argc, char *argv[])
> > > "list-controls");
> > > parser.addOption(OptListProperties, OptionNone, "List cameras properties",
> > > "list-properties");
> > > + parser.addOption(OptMonitor, OptionNone, "Monitor for hotplug and unplug camera events",
> > > + "monitor");
> > > options_ = parser.parse(argc, argv);
> > > if (!options_.valid())
> > > @@ -293,6 +301,16 @@ int CamApp::infoConfiguration()
> > > return 0;
> > > }
> > > +void CamApp::cameraAdded(std::shared_ptr<Camera> cam)
> > > +{
> > > + std::cout << "Camera Added: " << cam->name() << std::endl;
> > > +}
> > > +
> > > +void CamApp::cameraRemoved(std::shared_ptr<Camera> cam)
> > > +{
> > > + std::cout << "Camera Removed: " << cam->name() << std::endl;
> > > +}
> > > +
> > > int CamApp::run()
> > > {
> > > int ret;
> > > @@ -330,6 +348,12 @@ int CamApp::run()
> > > return capture.run(loop_, options_);
> > > }
> > > + if (options_.isSet(OptMonitor)) {
> > > + ret = loop_->exec();
> > > + if (ret)
> > > + std::cout << "Failed to run monitor loop" << std::endl;
> > > + }
> > > +
> > > return 0;
> > > }
> > > diff --git a/src/cam/main.h b/src/cam/main.h
> > > index 4a130d8..f61d288 100644
> > > --- a/src/cam/main.h
> > > +++ b/src/cam/main.h
> > > @@ -15,6 +15,7 @@ enum {
> > > OptInfo = 'I',
> > > OptList = 'l',
> > > OptListProperties = 'p',
> > > + OptMonitor = 'm',
> > > OptStream = 's',
> > > OptListControls = 256,
> > > };
> > > --
> > > 2.26.2
> > >
> > > _______________________________________________
> > > libcamera-devel mailing list
> > > libcamera-devel at lists.libcamera.org
> > > https://lists.libcamera.org/listinfo/libcamera-devel
--
Regards,
Niklas Söderlund
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